Great question! I knew there was a reason I liked you.įor that, we need to look at the type of material being used.ĭifferent materials rated in specific classes react differently as the temperature changes. Understand that if you are putting this information into practice, you should really look up ANSI B16.5.ĭO NOT rely solely on the chart above (to the right). SO, HOW WOULD YOU CONVERT AN ANSI CLASS TO A PSI RATING AND VICE VERSA? bolt connections rather than threaded). Most valves with flanged connections are traditionally expressed in ANSI classes.Īs far as I can tell, it’s just one of those quirks of the market. Some parts, though, are more commonly associated with classes than others. Specifically, I am talking about parts with flanged connections (i.e. It is very similar to a PSI and the pressure rating could be expressed as either an ANSI class or PSI. You can find both listed on a variety of parts. The standard we are concerned with is the ANSI B16.5, the class system for measuring allowable non-shock pressure as related to temperature. ANSI CLASS INTROĪNSI stands for American National Standards Institute, which oversees the measurement standards in the United States.ĪNSI works along with the American Society of Mechanical Engineers (ASME) to identify acceptable standards for all kinds of mechanical measures – from pipe thread taper to acoustic signal processing. It’s dozens of pages long and cannot be expressed in just a few paragraphs. To fully understand the system, you’ll want to research the documentation provided by the ANSI as described below (ANSI B16.5). Let me just start by saying this article is more of an introduction to the ANSI class system than an all-inclusive explanation. Please consult the ANSI B16.5 for pressure ratings of particular materials. This chart is an example of ANSI pressure class ratings for specific grades of steel. In this article, we’d like to talk about the exception to that rule, which is the ANSI class rating. Take a look through our website and you’ll see most of our pressure ratings are expressed as PSI - pounds per square inch.

600 psi to kpa