<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
	xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
	xmlns:georss="http://www.georss.org/georss" xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#" xmlns:media="http://search.yahoo.com/mrss/"
	>

<channel>
	<title>The3r's Weblog</title>
	<atom:link href="http://the3r.wordpress.com/feed/" rel="self" type="application/rss+xml" />
	<link>http://the3r.wordpress.com</link>
	<description>World Wide Web Google, Yahoo, Msn, Myspace, Friendster,</description>
	<lastBuildDate>Tue, 11 Sep 2007 15:17:41 +0000</lastBuildDate>
	<language>en</language>
	<sy:updatePeriod>hourly</sy:updatePeriod>
	<sy:updateFrequency>1</sy:updateFrequency>
	<generator>http://wordpress.com/</generator>
<cloud domain='the3r.wordpress.com' port='80' path='/?rsscloud=notify' registerProcedure='' protocol='http-post' />
<image>
		<url>http://s2.wp.com/i/buttonw-com.png</url>
		<title>The3r's Weblog</title>
		<link>http://the3r.wordpress.com</link>
	</image>
	<atom:link rel="search" type="application/opensearchdescription+xml" href="http://the3r.wordpress.com/osd.xml" title="The3r&#039;s Weblog" />
	<atom:link rel='hub' href='http://the3r.wordpress.com/?pushpress=hub'/>
		<item>
		<title>Flowmeter Application</title>
		<link>http://the3r.wordpress.com/2007/09/11/flowmeter-application/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/flowmeter-application/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:17:41 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/flowmeter-application/</guid>
		<description><![CDATA[Differential Pressure Orifice Meter Venturi Tube Flow Nozzles Pitot Tube Dall Tube Annubar Target Meter Rotameter Flow Tube Elbow Meters Positive Displacement Meters Rotary Meter Sliding Vane Meter Rotating Vane Meter Reciprocating Piston Meter Rotary Piston Meter Velocity Meter Turbine Meter Vortex Meter Electromagnetic Meter Ultrasonic Meter Mass Flowmeter Thermal Meter Coriolis Meter &#160; About [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=22&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p class="pagelink"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/differential-pressure.htm"><font color="#000000">Differential  Pressure</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/orifice-meter.htm"><font color="#000000">Orifice Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/venturi-tube.htm"><font color="#000000">Venturi Tube</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/flow-nozzles.htm"><font color="#000000">Flow Nozzles</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/pitot-tube.htm"><font color="#000000">Pitot Tube</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/dall-tube.htm"><font color="#000000">Dall Tube</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/annubar.htm"><font color="#000000">Annubar</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/target-meter.htm"><font color="#000000">Target Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/rotameter.htm"><font color="#000000">Rotameter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/flowtube.htm"><font color="#000000">Flow Tube</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/elbow-meters.htm"><font color="#000000">Elbow Meters</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/+vedisplacement-meter.htm"><font color="#000000">Positive Displacement  Meters</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/rotary-meter.htm"><font color="#000000">Rotary Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/slidingvane-meter.htm"><font color="#000000">Sliding Vane Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/rotatingvane-meter.htm"><font color="#000000">Rotating Vane Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/pistonmeter.htm"><font color="#000000">Reciprocating Piston Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/rotarymeter.htm"><font color="#000000">Rotary Piston Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/velocity-meter.htm"><font color="#000000">Velocity Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/turbine-meter.htm"><font color="#000000">Turbine Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/vortex-meter.htm"><font color="#000000">Vortex Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/electromagnetic-meter.htm"><font color="#000000">Electromagnetic  Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/ultrasonic-meter.htm"><font color="#000000">Ultrasonic Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/mass-flowmeter.htm"><font color="#000000">Mass Flowmeter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/thermal-meter.htm"><font color="#000000">Thermal Meter</font></a></font></p>
<p style="margin-top:0;margin-bottom:0;"><font face="Arial"><a href="http://the3r.wordpress.com/wp-admin/coriolis-meter.htm"><font color="#000000">Coriolis Meter</font></a></font></p>
<p class="pagelink">&nbsp;</p>
<p class="pagelink"><font face="Arial" size="2">About Peak  Flow Meters, Water Flow Meters, Flowmeter Companies, Fuel Flow Meters and Flow  Monitor Services.</font></p>
<p class="compdesc"><font face="Arial" size="2">Flow meters are used to measure the  flow of air, fluids and gas. Some of the most popular flow meters are: peak flow  meters, water flow meters, fuel flow meters, air flow meters, ultrasonic flow  meters, and flow monitor services. Many flow meters measure the volume of the  material while other flow meters measure the speed, and still other flow meters  measure the mass of the materials. For the most part, flow meters are used to  infer mass flow through calculations that flowmeter and flow monitor instruments  make after taking various flow measurements such as absolute pressure,  differential pressure, viscosity and temperature. Most flow meters including:  peak flow meters, water flow meters, and fuel flow monitors, are made up of  three parts: the primary device, transducer and transmitter. These three  flowmeter parts are usually combined into one so that the flowmeter is only one  instrument.</p>
<p>There are many different types of flow meters used for  different measurements of flow. Thermal mass flow meters take measurements with  two sensors that work together. A temperature sensor reference, and an active  heated sensor take measurements by calculating how much heat loss occurs in the  flowing liquid, and thus these flow meters can determine the flow rate based on  this amount. Another type of flowmeter is the Coriolis mass flow meter, which  operates on the basis of the Coriolis Effect. Basically, an excitation force is  applied to the flowmeter tube, causing the fluid or gas to rotate because the  acceleration is acting in opposite directions on both sides of the applied  force. A flowmeter measurement can then be taken. Other kinds of flow meters  operate using sound: these are called ultrasonic flow meters, and include  several types like Doppler Effect flow meters and time-of-flight flow  meters.</p>
<p>Because of their varied uses, flow meters are useful in a variety  of fields. Medically, flow meters are used to measure a patients air intake.  These types of flow meters are called peak flow meters and are particularly  beneficial for asthma patients. In plumbing, water flow meters are used to  measure the amount of fluid running through a tube for efficiency purposes. In  general, flow meters are used in many industrial purposes for flow measurements  to help companies determine profit gain or loss. Other industries that benefit  from the use of flow meters, peak flow meters, fuel flow meters, water flow  meters, and flow monitor services include the automotive industry, petroleum and  gas industries, utility services, HVAC, food processing and raw materials  industry.</p>
<p>Each type of flowmeter has specific guidelines that must be  followed for proper use. For example, when using a gas flow meters, the  flowmeter must remain full of gas. Liquid in gas flow meters can affect the flow  meters accuracy. Similarly, in order for liquid flow meters to work properly,  they must remain full of liquid. Gas in liquid flow meters can affect the  accuracy of flowmeter readings. Generally, contaminants of any kind will cause  an inaccurate reading of flow meters, so these flowmeter and flow monitor  instruments must be treated with care and cleaned regularly.</font></p>
<p class="pagelink"><font face="Arial" size="2">Types of Flow  Meters including: Peak Flow Meters, Water Flow Meters, Fuel Flow Meters, Air  Flow Meters, Mass Flow Meters, Flowmeter Companies and Flow Meter Manufacturers.  </font></p>
<p><font face="Arial" size="2"><br />
<strong>Coriolis mass flow meters</strong> are used  to measure the force of acceleration resulting from a moving object towards or  away from the center of rotation.</p>
<p><strong>Differential pressure flow  meters</strong> are used to measure the flow of fluids and gases in a pipe by  introducing constriction that causes the flowmeter pressure to drop. These flow  meters must be kept clean to result in accurate  measurements.</p>
<p><strong>Insertion flow meters</strong> measure flow at one position  in a pipe, and then, based on the flowmeter measurement, these flow meters  estimate the flow rate for the entire pipe.</p>
<p><strong>Magnetic flow meters</strong>  measure flow by creating a magnetic field that is channeled into the liquid and  causes a voltage signal to be sensed that is proportional to the flow of  liquid.</p>
<p><strong>Mass flow meters</strong> are used to measure gas flow and are one  of the more popular types of flow meters. This flowmeter is relatively  unaffected by changes in temperature or pressure in the mass flow meters tubes  or mass flow meters pipes.</p>
<p><strong>Open channel flow meters</strong> are used to  measure the flow of liquids when the channel flow meters are open to the  atmosphere.</p>
<p><strong>Peak flow meters</strong> are used by patients with asthma or  other lung disorders to measure the amount of air patients take into their  lungs. Peak flow meters allow physicians to further determine the severity of  any illness.</p>
<p><strong>Positive displacement flow meters</strong> trap liquid to  measure its flow by rotating parts that move between seals and the flowmeter  body.</p>
<p><strong>Sight flow</strong> indicators allow the operator to view the liquid  as it is moving. Some flow monitor and flow indicator models come equipped with  lights to enhance the visibility of the fluids.</p>
<p><strong>Target flow meters</strong>  measure the amount of force that is exerted on a target in a particular liquid  or gas. Readings from target flow meters should not be used to measure high  viscosity liquids because the target can be damaged.</p>
<p><strong>Thermal flow  meters</strong> are flow meters that use thermal properties of fluids to measure the  flow. Thermal flow meters are heated and as the liquid flows by, it can tell the  flow rate by the amount of heat lost.<br />
<strong><br />
Turbine flow meters </strong>consist  of a rotor that measures the fluid when it passes through the blades. The blade  speed of turbine flow meters is then translated into the speed of the  fluid.</p>
<p><strong>Ultrasonic flow meters</strong> use sound to determine flow rate.  Both Doppler Effect flow meters and time-of-flight flow meters are two types of  ultrasonic flow meters.</p>
<p><strong>Variable area flow meters</strong> measure by  letting the flow stream change the opening in the flowmeter with a movement of  an internal flowmeter part.</p>
<p><strong>Vortex flow meters</strong> and fluid flow  meters generate oscillations as a result of the flow that allows a flowmeter  measurement to be taken. </font></p>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/22/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/22/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/22/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/22/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/22/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/22/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/22/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/22/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/22/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/22/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/22/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/22/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/22/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/22/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/22/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/22/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=22&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/flowmeter-application/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>CONTROL VALVES is A final controlling element</title>
		<link>http://the3r.wordpress.com/2007/09/11/control-valves-is-a-final-controlling-element/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/control-valves-is-a-final-controlling-element/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:15:45 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/control-valves-is-a-final-controlling-element/</guid>
		<description><![CDATA[Introduction : CONTROL VALVES is A final controlling element, through which a fluid passes, which adjusts the size of flow passage as directed by a signal from a controller to modify the rate of flow of the fluid. Valve Flow Coefficient (Cv) &#8211; The number of US gallons per minute of 60°F water that will [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=21&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p align="left"><font size="2"><strong>I</strong></font><font size="2"><strong>n</strong></font><font size="2"><strong>troduction : </strong>CONTROL VALVES is A final controlling element,  through which a fluid passes, which adjusts the size of flow passage as directed  by a signal from a controller to modify the rate of flow of the fluid. <a href="http://the3r.wordpress.com/wp-admin/Cv_Coefficient">Valve Flow Coefficient (Cv)</a> &#8211; The number of US gallons  per minute of 60°F water that will flow through a valve with a one pound per  square inch pressure drop</font></p>
<p align="left"><font size="2">Rated Cv &#8211; The value of Cv at the valve full-open position</p>
<p>Rated Travel  &#8211; The linear movement of the valve plug from the closed position to the valve  full &#8211; open position<br />
Leakage &#8211; The quantity of fluid passing through an  assembled valve when the valve is in the closed postion<br />
On-Off Service &#8211; When  the valve is used to start / stop the flow by being cycled to the full open or  to full closed position<br />
Modulating Service &#8211; When the valve is being used to  throttle or regulate the flow by varying the opening between open and closed  positions<br />
Maximum shut-off Pressure &#8211; The pressure of the fluid flowing into  the valve against which the valve will have to close Service Temperature &#8211; The  maximum and minimum temperature of the media<br />
Supply Pressure &#8211; The plant air  supply pressure available to operate a pneumatic actuator<br />
Stem Torque &#8211; The  force required at the valve stem to open or close the valve against system  pressure and service conditions<br />
Capactiy &#8211; Rate of flow through the valve  under stated conditions<br />
Fail close &#8211; The condition wherein the valve port  remains closed should the actuating power fail<br />
Fail open &#8211; The condition  wherein the valve port remains open should the actuating power fail<br />
Fail  last &#8211; The condition wherein the valve port remains in the last position should  the actuating power fail</font></p>
<p align="left"><font size="2"><strong>Application :</strong> A Control Valve is a  power-operated device used to modify the fluid flow rate in a process system.  Well, what happens if the power is cut off? When a Control Valve is sized or  selected to do a particular job, one of the first questions you should consider  is how that valve will respond in the event of a loss of signal or power. This  is called its &#8220;fail-safe mode&#8221; and knowing the fail-safe mode is the key to  troubleshooting it. In most applications (about 80%), it is desirable for valves  to fail closed. In other applications, you might want a valve to fail open or  fail in place. Safety concerns and process requirements will mandate the fall  mode of the valve. When a valve is not sitting in its fail position, is is being  told how and when to move by some external signal. By the comments one hears,  you would be led to believe that control valves sit around and think up things  to do on their own. Perhaps this will some day be true when all control valves  are &#8220;smart.&#8221; If a Control Valve is observed in an unstable condition or appears  to not be responding correctly to an input signal, remember that something is  telling the valve to behave that way.<br />
A control valve is only as strong as  its weakest link. When the 1965 Ford Mustang first appeared, it was powered by a  6-cylinder engine with a 3-speed transmission &#8211; but it had a 140 m.p.h.(225  k.p.h.) speedometer. The fact that it had a 140 m.p.h.(225 k.p.h.) speedometer  did not mean it could actually travel that fast. In the same way, a control  valve with a 600# rated valve body cannot throttle and shut off against 1440  pounds of pressure. There are two basic types of control valves: rotary and  linear. Linear-motion control valves commonly have globe, gate, diaphragm, or  pinch &#8211; type closures. Rotary-motion valves have ball, butterfly, or plug  closures. Each type of valve has its special generic features, which may, in a  given application, be either an advantage or a disadvantage<br />
</font></p>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/21/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/21/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/21/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/21/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/21/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/21/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/21/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/21/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/21/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/21/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/21/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/21/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/21/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/21/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/21/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/21/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=21&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/control-valves-is-a-final-controlling-element/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Butterfly Valves</title>
		<link>http://the3r.wordpress.com/2007/09/11/butterfly-valves/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/butterfly-valves/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:13:53 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/butterfly-valves/</guid>
		<description><![CDATA[Butterfly Valves Butterfly valves are throttling valves used to control flow through a circular disc by turning the valve’s main axis at ninety degree or right angles towards the direction of flow in the pipe. These valves use an inflatable seat to seal with air pressure, thus requiring less torque and a smaller actuator, resulting [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=20&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/08/butterfly-valves/" title="Butterfly Valves" rel="bookmark">Butterfly  Valves</a></h2>
<p class="entrytext">Butterfly valves are throttling valves used to control flow through a  circular disc by turning the valve’s main axis at ninety degree or right angles  towards the direction of flow in the pipe. These valves use an inflatable seat  to seal with air pressure, thus requiring less torque and a smaller actuator,  resulting in lower overall valve cost.</p>
<p class="bodytext" align="justify">The demand for actuated butterfly valves is  growing because actuated butterfly valves can provide: precise, repeatable  control for industrial process, complex automatic sequencing for process  control. These important industrial fittings control the flow of gas or liquid  by means of a disk, which turns on a diametrical axis inside a pipe or by two  semicircular plates hinged on a common spindle, which permits flow in a single  direction. These compactly designed valves offer a rotary system movement of  less than 90 degree. The valves are manufactured in materials including  stainless steel, plastic, ceramic and PVC.<strong>Advantage of Butterfly Valves </strong><br />
These valves  can be used in areas where space is limited, this is so, because butterfly  valves are available in small dimensions and are used in a variety of chemical  services.</p>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/20/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/20/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/20/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/20/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/20/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/20/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/20/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/20/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/20/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/20/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/20/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/20/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/20/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/20/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/20/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/20/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=20&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/butterfly-valves/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Types of Check Valves</title>
		<link>http://the3r.wordpress.com/2007/09/11/types-of-check-valves/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/types-of-check-valves/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:13:35 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/types-of-check-valves/</guid>
		<description><![CDATA[Check Valves A check valve is a mechanical device used as an industrial/plumbing fitting, which normally allows fluid or gas to flow through it in uni-direction. A double check valve is often used to prevent back flow and to keep potentially contaminated water from siphoning back. Clapper valves, a type of check valve is used [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=19&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/08/check-valves/" title="Check Valves" rel="bookmark">Check  Valves</a></h2>
<p class="entrytext">A check valve is a mechanical device used as an industrial/plumbing fitting,  which normally allows fluid or gas to flow through it in uni-direction. A double  check valve is often used to prevent back flow and to keep potentially  contaminated water from siphoning back. Clapper valves, a type of check valve is  used in or with firefighting, and has a hinged gate (often with a spring urging  it shut) that only remains open in the outflowing direction.</p>
<p class="bodytext" align="justify"><strong>Types of Check Valves  </strong></p>
<ul>
<li><strong>Single Disc Swing Valves : </strong>These valves can be mounted both  vertically as ell as horizontally and are designed with a closure element  attached to the top of the cap. This closure element can be pushed aside by the  flow, but swings back into the close position upon flow reversal.</li>
<li><strong>Double Disc or Wafer Check Valves : </strong>These valves consist of  two half-circle disks hinged together that fold together upon positive flow and  retract to a full-circle to close against reverse flow.</li>
<li><strong>Lift-Check Valves :</strong> These valves can operate in either  vertical or horizontal mounting.</li>
<li><strong>Silent valves :</strong> These valves are quite similar to lift  check valves with a center guide extending from inlet to outlet ports.</li>
<li><strong>Ball-Check Valves :</strong> These valves are good for most services  and can even handle fluids that produce gummy deposits. Since the disc is free  to rotate, this all helps to keep the valve seats clean.</li>
<li><strong>Cone Check Valves : </strong>These valves use a free-floating or  spring loaded cone resting in the seat ring as the closure element. Incase of a  reverse flow, the cone is forced back into its seat preventing back flow.</li>
</ul>
<p class="bodytext" align="justify"><strong>Application of Check  Valves</strong></p>
<ul>
<li>Few types of irrigation sprinklers and drip irrigation emitters have small  check valves built into them to keep the lines from draining when the system is  shut off.</li>
<li>Offshore Oil and Gas</li>
<li>Civil Engineering</li>
<li>Gas-Turbine Systems</li>
</ul>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/19/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/19/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/19/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/19/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/19/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/19/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/19/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/19/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/19/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/19/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/19/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/19/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/19/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/19/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/19/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/19/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=19&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/types-of-check-valves/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Control Valves</title>
		<link>http://the3r.wordpress.com/2007/09/11/control-valves/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/control-valves/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:13:16 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/control-valves/</guid>
		<description><![CDATA[Control Valves A Control Valve is an important industrial fitting device used to modify and control the fluid flow rate in a process system. Also known as proportional valve, this power-operated device can be used to modify pressure rate in a process system. There are various specifications and parameters which must be considered for these [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=18&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/08/control-valves-2/" title="Control Valves" rel="bookmark">Control  Valves</a></h2>
<p class="entrytext">A Control Valve is an important industrial fitting device used to modify and  control the fluid flow rate in a process system. Also known as proportional  valve, this power-operated device can be used to modify pressure rate in a  process system.</p>
<p class="bodytext" align="justify">There are various specifications and  parameters which must be considered for these power-operated valves including  diameter, working pressure and operating temperature. Available in choice of  material including copper, brass, bronze, cast iron and stainless steel, and  other plastic material such as PVC AND CPVC, these valves are the most used  fittings.<strong>Types of Control Valves</strong><br />
Globe, Gate,  Diaphragm, Needle, Butterfly, Ball and Plug Valves are all, kinds of control  valves and are used for different applications in large number of  industries.</p>
<p><strong>Application of Control Valves</strong></p>
<ul>
<li>Waterworks</li>
<li>Fire Protection</li>
<li>Irrigation</li>
<li>Industrial</li>
<li>Petroleum</li>
<li>Aviation Fueling</li>
</ul>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/18/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/18/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/18/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/18/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/18/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/18/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/18/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/18/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/18/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/18/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/18/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/18/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/18/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/18/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/18/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/18/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=18&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/control-valves/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Gate Valves</title>
		<link>http://the3r.wordpress.com/2007/09/11/gate-valves/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/gate-valves/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:12:56 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/gate-valves/</guid>
		<description><![CDATA[Gate Valves Gate valves, also known as Slide or Knife Valves, are named after a wedge-shaped internal plastic barrier, called a gate which rises and falls inside the valve as a handle is turned. These are linear motion valves in a which a flat closure element slides into the flow stream to provide shut off [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=17&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/08/gate-valves/" title="Gate Valves" rel="bookmark">Gate  Valves</a></h2>
<p class="entrytext">Gate valves, also known as Slide or Knife Valves, are named after a  wedge-shaped internal plastic barrier, called a gate which rises and falls  inside the valve as a handle is turned. These are linear motion valves in a  which a flat closure element slides into the flow stream to provide shut off and  are designed to minimize pressure drop across the valve in the fully opened  position and stop the flow of fluid completely.</p>
<p class="bodytext" align="justify">Knife valves effectively regulate flow rates  from zero to full flow, they work well with solids-laden water, and these valves  can be serviced in place. Knife Gate valves work well in applications involving  slurries as the ‘gates’ can cut through the slurry, also these valves are  advantageous in applications involving viscous liquids such as heavy oils,  varnish, molasses etc.<strong>Types of Gate Valves</strong></p>
<ul>
<li><strong>Parallel Gate Valves:</strong> These valves use a flat disc gate  between two parallel seats located upstream and downstream.</li>
<li><strong>Wedge-Shaped Gate Valves:</strong> These valves use two inclines  seats and a little mismatched inclined gate allowing tight shut-off.</li>
</ul>
<p class="bodytext"><strong>Application of Gate Valves</strong></p>
<ul>
<li>Viscous liquids such as heavy oils, creams etc.</li>
<li>Slurries</li>
</ul>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/17/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/17/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/17/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/17/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/17/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/17/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/17/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/17/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/17/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/17/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/17/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/17/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/17/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/17/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/17/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/17/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=17&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/gate-valves/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Globe Valves</title>
		<link>http://the3r.wordpress.com/2007/09/11/globe-valves/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/globe-valves/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:12:40 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/globe-valves/</guid>
		<description><![CDATA[Globe Valves Globe Valves Globe valves derive their name from the rounded bodies/spherical shape and are widely used in fitting industry to regulate fluid flow in both on/off and throttling service. These linear motion valves consist of moving parts including disk, the valve stem, and the hand wheel.The stem is used to connect the hard [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=16&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/08/globe-valves-2/" title="Globe Valves" rel="bookmark">Globe  Valves</a></h2>
<p class="entrytext">Globe Valves</p>
<p class="bodytext" align="justify">Globe valves derive their name from the  rounded bodies/spherical shape and are widely used in fitting industry to  regulate fluid flow in both on/off and throttling service. These linear motion  valves consist of moving parts including disk, the valve stem, and the hand  wheel.The stem is used to connect the hard wheel and the disk; the valves are  threaded and fit into the threads of the valve bonnet. These specialty valves  allow fluids to pass the spaces between the edge of the disk and the seat when  open.</p>
<p><strong>Types of Globe Valves </strong><br />
These valves are  available in three main body types, namely : <strong>Angle Design, Y-design and  Multi-piece Design.</strong> Angle valves are a type of globe valves, so  designed, that the inlet and outlet are perpendicular, for transferring flow  from vertical to horizontal. Y-design valves derive linear action from the  incline between the axis of the inlet and outlet ports. The inlet and outlet are  not of single piece construction. These valves offer precise throttling and  control and have high-pressure limits. They also offer a low coefficient of flow  and are however not good selections in applications requiring cleanliness or  sterility.</p>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/16/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/16/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/16/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/16/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/16/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/16/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/16/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/16/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/16/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/16/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/16/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/16/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/16/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/16/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/16/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/16/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=16&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/globe-valves/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Cavitation</title>
		<link>http://the3r.wordpress.com/2007/09/11/cavitation/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/cavitation/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:12:16 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/cavitation/</guid>
		<description><![CDATA[Cavitation Cavitation is a general term used to describe the behavior of voids or bubbles in a liquid. Cavitation is usually divided into two classes of behavior: inertial (or transient) cavitation and non-inertial cavitation. Inertial cavitation is the process where a void or bubble in a liquid rapidly collapses, producing a shock wave. Such cavitation [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=15&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/08/cavitation-2/" title="Cavitation" rel="bookmark">Cavitation</a></h2>
<p class="entrytext">Cavitation is a general term used to describe the behavior of voids or  bubbles in a liquid. Cavitation is usually divided into two classes of behavior:  inertial (or transient) cavitation and non-inertial cavitation. Inertial  cavitation is the process where a void or bubble in a liquid rapidly collapses,  producing a shock wave. Such cavitation often occurs in pumps, propellers,  impellers, and in the vascular tissues of plants. Non-inertial cavitation is the  process where a bubble in a fluid is forced to oscillate in size or shape due to  some form of energy input, such as an acoustic field. Such cavitation is often  employed in ultrasonic cleaning baths and can also be observed in pumps,  propellers etc.</p>
<p>nertial cavitation was first studied by Lord Rayleigh in the late 19th  century when he considered the collapse of a spherical void within a liquid.  When a volume of liquid is subjected to a sufficiently low pressure it may  rupture and form a cavity. This phenomenon is termed cavitation inception and  may occur behind the blade of a rapidly rotating propeller or on any surface  vibrating underwater with sufficient amplitude and acceleration. Other ways of  generating cavitation voids involve the local deposition of energy such as an  intense focussed laser pulse (optic cavitation) or with an electrical discharge  through a spark. Vapor gasses evaporate into the cavity from the surrounding  medium, thus the cavity is not a perfect vacuum but has a relatively low gas  pressure. Such a low pressure cavitation bubble in a liquid will begin to  collapse due to the higher pressure of the surrounding medium. As the bubble  collapses, the pressure and temperature of the vapor within will increase. The  bubble will eventually collapse to a minute fraction of its original size, at  which point the gas within dissipates into the surrounding liquid via a rather  violent mechanism, which releases a significant amount of energy in the form of  an acoustic shock-wave and as visible light. At the point of total collapse, the  temperature of the vapor within the bubble may be several thousand kelvins, and  the pressure several hundred atmospheres.</p>
<p>Inertial cavitation can also occur in the presence of an acoustic field.  Microscopic gas bubbles which are generally present in a liquid will be forced  to oscillate due to an applied acoustic field. If the acoustic intensity is  sufficiently high, the bubbles will first grow in size, and then rapidly  collapse. Hence, inertial cavitation can occur even if the rarefraction in the  liquid is insufficient for a Rayleigh-like void to occur. High power ultrasonics  usually utilize the inertial cavitation of microscopic vacuum bubbles for  treatment of surfaces, liquids and slurries.</p>
<p>The physical process of cavitation inception is similar to boiling. The major  difference between the two is the thermodynamic paths which precede the  formation of the vapor. Boiling occurs when the local vapor pressure of the  liquid rises above its local ambient pressure and sufficient energy is present  to cause the phase change to a gas. Cavitation inception occurs when the local  pressure falls sufficiently far below the saturated vapor pressure, a value  given by the tensile strength of the liquid.</p>
<p>In order for cavitation inception to occur, the cavitation “bubbles”  generally need a surface on which they can nucleate. This surface can be  provided by the sides of a container or by impurities in the liquid or by small  undissolved microbubble within the liquid. It is generally accepted that  hydrophobic surfaces stabilize small bubbles. These pre-existing bubbles start  to grow unbounded when they are exposed to a pressure below the threshold  pressure, termed Blake’s threshold.</p>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/15/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/15/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/15/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/15/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/15/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/15/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/15/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/15/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/15/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/15/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/15/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/15/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/15/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/15/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/15/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/15/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=15&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/cavitation/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Cavitation Valve</title>
		<link>http://the3r.wordpress.com/2007/09/11/cavitation-valve/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/cavitation-valve/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:11:57 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/cavitation-valve/</guid>
		<description><![CDATA[Cavitation Valve If the speed through the valve is high enough, the pressure in the liquid may drop to a level where the fluid may start bubble or flash. The pressure recovers sufficiently and the bubbles collapse upon themselves. control valve cavitation Cavitation may be noisy but is usually of low intensity and low frequency. [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=14&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/08/cavitation-valve/" title="Cavitation Valve" rel="bookmark">Cavitation Valve</a></h2>
<p class="entrytext">If the speed through the valve is high enough, the pressure in the liquid may  drop to a level where the fluid may start bubble or flash. The pressure recovers  sufficiently and the bubbles collapse upon themselves.</p>
<p>control valve cavitation</p>
<p>Cavitation may be noisy but is usually of low intensity and low frequency.  This situation is extremely destructive and may wear out the trim and body parts  of the valve in short time.</p>
<p>* The Cavitation Number An introduction to and a definition of the Cavitation  Number.<br />
* Cavitation &#8211; an Introduction</p>
<p>Application Ratio</p>
<p>A common way to characterize potential cavitation conditions is the  “applications ratio” (or “the incipient cavitation index”) and can be expressed  as</p>
<p>AR = pi &#8211; po / (pi &#8211; pv) (1)</p>
<p>where</p>
<p>AR = Application Ratio</p>
<p>pi = inlet pressure, absolute</p>
<p>po = outlet pressure, absolute</p>
<p>pv = vapor pressure of the fluid, absolute</p>
<p>For application ratios above 1 &#8211; the fluid flashes. This is not the same as  cavitation, but the closer the ratio is to 1, the higher the potential for  cavitation.</p>
<p>Note! With an increasing fluid temperature the possibility for cavitation  increases.<br />
Example &#8211; Flashing Water</p>
<p>If we know the boiling point and the absolute pressure of a fluid (Steam  Table with saturated steam properties) the minimum outlet pressure from a valve  to avoid flashing can be calculated.</p>
<p>For an application ratio of one equation (1) can modified to</p>
<p>AR = 1 = pi &#8211; po / (pi &#8211; pv)</p>
<p>or transformed</p>
<p>po = pv</p>
<p>Using “Steam Table” with saturated steam properties we can conclude that</p>
<p>* for a water temperature of 17.51 oC and absolute inlet pressure of 1 bar &#8211;  the minimum outlet pressure is 0.02 bar to avoid flashing<br />
* for a water  temperature of 81.35 oC and absolute inlet pressure of 1 bar &#8211; the minimum  outlet pressure is 0.5 bar to avoid flashing<br />
* For a water temperature of  99.63 oC and absolute inlet pressure of 1 bar &#8211; the minimum outlet pressure is 1  bar to avoid flashing</p>
<p>Note! Flashing is not the same as cavitation. Due to local conditions in a  valve cavitation may start on much higher outlet pressures.<br />
Multi Stage  Control Valves</p>
<p>Cavitation can be avoided by using more than one control valve or more  convenient &#8211; a multistage control valve.</p>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/14/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/14/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/14/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/14/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/14/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/14/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/14/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/14/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/14/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/14/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/14/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/14/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/14/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/14/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/14/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/14/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=14&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/cavitation-valve/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
		<item>
		<title>Technical Principles of Valves</title>
		<link>http://the3r.wordpress.com/2007/09/11/technical-principles-of-valves/</link>
		<comments>http://the3r.wordpress.com/2007/09/11/technical-principles-of-valves/#comments</comments>
		<pubDate>Tue, 11 Sep 2007 15:11:04 +0000</pubDate>
		<dc:creator>the3r</dc:creator>
				<category><![CDATA[Tech]]></category>

		<guid isPermaLink="false">http://the3r.wordpress.com/2007/09/11/technical-principles-of-valves/</guid>
		<description><![CDATA[Technical Principles of Valves Risk, Reliability and Safety Hazardous areas classifications, types of protection, rating systems and critical temperatures. Sizing Steam and Condensate Pipes GENERAL Solenoid valves are used wherever fluid flow has to be controlled automatically. They are being used to an increasing degree in the most varied types of plants and equipment. The [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=13&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<h2><a href="http://www.intro4u2u.com/2007/01/technical-principles-of-valves/" title="Technical Principles of Valves" rel="bookmark">Technical Principles of Valves</a></h2>
<p class="entrytext">Risk, Reliability and Safety</p>
<p>Hazardous areas classifications, types of protection, rating systems and  critical temperatures.<br />
Sizing Steam and Condensate Pipes<br />
GENERAL</p>
<p>Solenoid valves are used wherever fluid flow has to be controlled  automatically. They are being used to an increasing degree in the most varied  types of plants and equipment. The variety of different designs which are  available enables a valve to be selected to specifically suit the application in  question.</p>
<p>CONSTRUCTION</p>
<p>Solenoid valves are control units which, when electrically energized or  de-energized, either shut off or allow fluid flow. The actuator takes the form  of an electromagnet. When energized, a magnetic field builds up which pulls a  plunger or pivoted armature against the action of a spring. When de-energized,  the plunger or pivoted armature is returned to its original position by the  spring action.</p>
<p>VALVE OPERATION</p>
<p>According to the mode of actuation, a distinction is made between  direct-acting valves, internally piloted valves, and externally piloted valves.  A further distinguishing feature is the number of port connections or the number  of flow paths (”ways”).</p>
<p>DIRECT-ACTING VALVES</p>
<p>With a direct-acting solenoid valve, the seat seal is attached to the  solenoid core. In the de-energized condition, a seat orifice is closed, which  opens when the valve is energized.</p>
<p>DIRECT-ACTING 2-WAY VALVES</p>
<p>Two-way valves are shut-off valves with one inlet port and one outlet port  (Fig. 1). In the de-energized condition, the core spring, assisted by the fluid  pressure, holds the valve seal on the valve seat to shut off the flow. When  energized, the core and seal are pulled into the solenoid coil and the valve  opens. The electro-magnetic force is greater than the combined spring force and  the static and dynamic pressure forces of the medium.</p>
<p>DIRECT-ACTING 3-WAY VALVES</p>
<p>Three-way valves have three port connections and two valve seats. One valve  seal always remains open and the other closed in the de-energized mode. When the  coil is energized, the mode reverses. The 3-way valve shown in Fig. 2 is  designed with a plunger type core. Various valve operations can be obtained  according to how the fluid medium is connected to the working ports in Fig. 2.  The fluid pressure builds up under the valve seat. With the coil de-energized, a  conical spring holds the lower core seal tightly against the valve seat and  shuts off the fluid flow. Port A is exhausted through R. When the coil is  energized the core is pulled in, the valve seat at Port R is sealed off by the  spring-loaded upper core seal. The fluid medium now flows from P to A.</p>
<p>Unlike the versions with plunger-type cores, pivoted-armature valves have all  port connections in the valve body. An isolating diaphragm ensures that the  fluid medium does not come into contact with the coil chamber. Pivoted-armature  valves can be used to obtain any 3-way valve operation. The basic design  principle is shown in Fig. 3. Pivoted-armature valves are provided with manual  override as a standard feature.</p>
<p>INTERNALLY PILOTED SOLENOID VALVES</p>
<p>With direct-acting valves, the static pressure forces increase with  increasing orifice diameter which means that the magnetic forces, required to  overcome the pressure forces, become correspondingly larger. Internally piloted  solenoid valves are therefore employed for switching higher pressures in  conjunction with larger orifice sizes; in this case, the differential fluid  pressure performs the main work in opening and closing the valve.</p>
<p>INTERNALLY PILOTED 2-WAY VALVES</p>
<p>Internally piloted solenoid valves are fitted with either a 2- or 3-way pilot  solenoid valve. A diaphragm or a piston provides the seal for the main valve  seat. The operation of such a valve is indicated in Fig. 4. When the pilot valve  is closed, the fluid pressure builds up on both sides of the diaphragm via a  bleed orifice. As long as there is a pressure differential between the inlet and  outlet ports, a shut-off force is available by virtue of the larger effective  area on the top of the diaphragm. When the pilot valve is opened, the pressure  is relieved from the upper side of the diaphragm. The greater effective net  pressure force from below now raises the diaphragm and opens the valve. In  general, internally piloted valves require a minimum pressure differential to  ensure satisfactory opening and closing. Omega also offers internally piloted  valves, designed with a coupled core and diaphragm that operate at zero pressure  differential (Fig. 5).</p>
<p>INTERNALLY PILOTED MULTI-WAY SOLENOID VALVES</p>
<p>Internally piloted 4-way solenoid valves are used mainly in hydraulic and  pneumatic applications to actuate double-acting cylinders. These valves have  four port connections: a pressure inlet P, two cylinder port connections A and  B, and one exhaust port connection R. An internally piloted 4/2-way poppet valve  is shown in Fig. 6. When de-energized, the pilot valve opens at the connection  from the pressure inlet to the pilot channel. Both poppets in the main valve are  now pressurized and switch over. Now port connection P is connected to A, and B  can exhaust via a second restrictor through R.</p>
<p>EXTERNALLY PILOTED VALVES</p>
<p>With these types an independent pilot medium is used to actuate the valve.  Fig. 7 shows a piston-operated angle-seat valve with closure spring. In the  unpressurized condition, the valve seat is closed. A 3-way solenoid valve, which  can be mounted on the actuator, controls the independent pilot medium. When the  solenoid valve is energized, the piston is raised against the action of the  spring and the valve opens. A normally-open valve version can be obtained if the  spring is placed on the opposite side of the actuator piston. In these cases,  the independent pilot medium is connected to the top of the actuator.  Double-acting versions controlled by 4/2-way valves do not contain any  spring.</p>
<p>MATERIALS</p>
<p>All materials used in the construction of the valves are carefully selected  according to the varying types of applications. Body material, seal material,  and solenoid material are chosen to optimize functional reliability, fluid  compatibility, service life and cost.</p>
<p>BODY MATERIALS</p>
<p>Neutral fluid valve bodies are made of brass and bronze. For fluids with high  temperatures, e.g., steam, corrosion-resistant steel is available. In addition,  polyamide material s used for economic reasons in various plastic valves.</p>
<p>SOLENOID MATERIALS</p>
<p>All parts of the solenoid actuator which come into contact with the fluid are  made of austenitic corrosion-resistant steel. In this way, resistance is  guaranteed against corrosive attack by neutral or mildly aggressive media.</p>
<p>SEAL MATERIALS</p>
<p>The particular mechanical, thermal and chemical conditions in an application  factors in the selection of the seal material. the standard material for neutral  fluids at temperatures up to 194°F is normally Viton. For higher temperatures  EPDM and PTFE are employed. The PTFE material is universally resistant to  practically all fluids of technical interest.</p>
<p>PRESSURE RATINGS &#8211; PRESSURE RANGE</p>
<p>All pressure figures quoted in this section represent gauge pressures.  Pressure ratings are quoted in PSI. The valves function reliably within the  given pressure ranges. Our figures apply for the range 15% undervoltage to 10%  overvoltage. If 3/2-way valves are used in a different operation, the permitted  pressure range changes. Further details are contained in our data sheets.</p>
<p>In the case of vacuum operation, care has to be taken to ensure that the  vacuum is on the outlet side (A or B) while the higher pressure, i.e.  atmospheric pressure, is connected to the inlet port P.</p>
<p>FLOW RATE VALUES</p>
<p>The flow rate through a valve is determined by the nature of the design and  by the type of flow. The size of valve required for a particular application is  generally established by the Cv rating. This figure is evolved for standardized  units and conditions, i.e. flowrate in GPM and using water at a temperature of  between 40°F and 86°F at a pressure drop of 1 PSI. Cv ratings for each valve are  quoted. A standardized system of flowrate values is also used for pneumatics. In  this case the air flow in SCFM upstream and a pressure drop of 15 PSI at a  temperature of 68°F.</p>
<p>SOLENOID ACTUATOR</p>
<p>A common feature of all Omega solenoid valves is the epoxy-encapsulated  solenoid system. With this system, the whole magnetic circuit-coil, connections,  yoke and core guide tube &#8211; are incorporated in one compact unit. This results in  a high magnetic force being contained within the minimum of space, insuring  first class electrical insulation and protection against vibration, as well as  external corrosive effects.</p>
<p>COILS</p>
<p>The Omega coils are available in all the commonly used AC and DC voltages.  The low power consumption, in particular with the smaller solenoid systems,  means that control via solid state circuitry is possible.</p>
<p>The magnetic force available increases as the air gap between the core and  plug nut decreases, regardless of whether AC or DC is involved. An AC solenoid  system has a larger magnetic force available at a greater stroke than a  comparable DC solenoid system. The characteristic stroke vs. force graphs,  indicated in Fig. 8, illustrate this relationship.</p>
<p>The current consumption of an AC solenoid is determined by the inductance.  With increasing stroke the inductive resistance decreases and causes an increase  in current consumption. This means that at the instant of de-energization, the  current reaches its maximum value. The opposite situation applies to a DC  solenoid where the current consumption is a function only of the resistance of  the windings. A time-based comparison of the energization characteristics for AC  and DC solenoids is shown in Fig. 9. At the moment of being energized, i.e. when  the air gap is at its maximum, solenoid valves draw much higher currents than  when the core is completely retracted, i.e., the air gap is closed. This results  in a high output and increased pressure range. In DC systems, after switching on  the current, flow increases relatively slowly until a constant holding current  is reached. These valves are therefore, only able to control lower pressures  than AC valves at the same orifice sizes. Higher pressures can only be obtained  by reducing the orifice size and, thus, the flow capability.</p>
<p>THERMAL EFFECTS</p>
<p>A certain amount of heat is always generated when a solenoid coil is  energized. The standard version of the solenoid valves has relatively low  temperature rises. They are designed to reach a maximum temperature rise of  144°F under conditions of continuous operation (100%) and at 10% overvoltage. In  addition, a maximum ambient temperature of 130°F is generally permissible. The  maximum permissible fluid temperatures are dependent on the particular seal and  body materials specified. These figures can be obtained from the technical  data.</p>
<p>TIME DEFINITIONS (VDE0580) RESPONSE TIMES</p>
<p>The small volumes and relatively high magnetic forces involved with solenoid  valves enable rapid response times to be obtained. Valves with various response  times are available for special applications. The response time is defined as  the time between application of the switching signal and completion of  mechanical opening or closing.</p>
<p>ON PERIOD</p>
<p>The on period is defined as the time between switching the solenoid current  on and off.</p>
<p>CYCLE PERIOD</p>
<p>The total time of the energized and de-energized periods is the cycle period.  Preferred cycle period: 2, 5, 10 or 30 minutes.</p>
<p>RELATIVE DUTY CYCLE</p>
<p>The relative duty cycle (%) is the percentage ratio of the energized period  to the total cycle period. Continuous operation (100% duty cycle) is defined as  continuous operation until steady-state temperature is reached.</p>
<p>VALVE OPERATION</p>
<p>The coding for the valve operation always consists of a capital letter. The  summary at left details the codes of the various valve operations and indicates  the appropriate standard circuit symbols.</p>
<p>VISCOSITY</p>
<p>The technical data is valid for viscosities up to the figure quoted. Higher  viscosities are permissible, but in these cases the voltage tolerance range is  reduced and the response times are extended.</p>
<p>TEMPERATURE RANGE</p>
<p>Temperature limits for the fluid medium are always detailed. Various factors,  e.g. ambient conditions, cycling, speed, voltage tolerance, installation  details, etc., can, however, influence the temperature performance. The values  quoted herein should, therefore, be used only as a general guide. In cases where  operation at extremes of the temperature range are involved, you should seek  advice from Omega’s Engineering Department.<br />
Sizing of steam and condensate  pipes and tubes, pressure loss in piping, recommended speed and  capacities<br />
Steam &amp; Condensate Systems</p>
<p>Steam is an integral and essential part of modern industrial process  technology. Without steam, food, textile, chemical, medical, power, heating and  transport industries could not exist or perform as they do. In this section  necessary information as steam properties, steam and condensate piping and much  more is provided<br />
Steam Thermodynamics</p>
<p>The basic thermodynamic of steam and condensate<br />
Temperature  Measurement</p>
<p>Measurement of temperature; probes, sensors and transmitters<br />
Thermal  Expansion of Pipes and Tubes</p>
<p>Thermal expansion of pipes and piping applications<br />
Thermodynamics</p>
<p>Thermodynamics is the branch of physics which deals with the transformation  of heat into mechanical work<br />
Valve Selection Guide</p>
<p>An applications guide for selecting valves<br />
Valves and Valve Standards</p>
<p>International standards common used for valves<br />
Ventilation Systems</p>
<p>Systems for ventilation and air handling<br />
Water Systems</p>
<p>Design properties for hot and cold water systems. Capacities, users  consumptions, use of energy and more. Anyone involved in design, analysis,  operation, maintenance or rehabilitation of water distribution systems will find  practical guidance in this section. Hydraulics of pressurized flow, piping  design and pipeline systems, storage issues and more</p>
<br /><img alt="" border="0" src="http://feeds.wordpress.com/1.0/categories/the3r.wordpress.com/13/" /> <img alt="" border="0" src="http://feeds.wordpress.com/1.0/tags/the3r.wordpress.com/13/" /> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/the3r.wordpress.com/13/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/the3r.wordpress.com/13/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/the3r.wordpress.com/13/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/the3r.wordpress.com/13/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/the3r.wordpress.com/13/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/the3r.wordpress.com/13/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/the3r.wordpress.com/13/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/the3r.wordpress.com/13/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/the3r.wordpress.com/13/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/the3r.wordpress.com/13/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/the3r.wordpress.com/13/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/the3r.wordpress.com/13/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/the3r.wordpress.com/13/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/the3r.wordpress.com/13/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=the3r.wordpress.com&amp;blog=1428690&amp;post=13&amp;subd=the3r&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
			<wfw:commentRss>http://the3r.wordpress.com/2007/09/11/technical-principles-of-valves/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
	
		<media:content url="http://1.gravatar.com/avatar/dc4cc97a5d3f3269f7d0c28c9b997e8f?s=96&#38;d=identicon" medium="image">
			<media:title type="html">the3r</media:title>
		</media:content>
	</item>
	</channel>
</rss>
