media vs valve

I'm having a little trouble understanding what you're asking but if I interpret it, you want to know:

What specifications or information do I need to provide to a supplier so that he can tell what valve to offer?

Is this correct? Or are you asking:

How do I calculate the correct type and size of valve for a particular application?

sorry if my question make u confuse..my question is not what u interpret is..actually, i want to know valve in different media like water,oil, gas must have different characteristics right..maybe for example valve in water have different shape compare to valve in oil or gas..this is example because i'm not sure what it is..actually i'm a student..this is part of my research..

tq

Ah! This post might be referring to the shape of the valve trim in a modulating valve involved in flow control. The shape selected can significantly effect the performance of a control system and in the limit, its stability.

Keywords: linear, equal percentage, trim shapes.

Resources: control textbooks.

Any takers?

valve in water have different shape compare to valve in oil or gas

Not exactly. The shape may be the same but the materials of construction will definitely be different. The different valve shapes have more to do with application. A butterfly valve is used more to start or stop the flow while a globe valve is used to control the flow. A ball valve basically has the same function as a butterfly valve but is more suitable for higher pressures.

Learning about valves takes a whole book! I know because I've read a few of them. There are websites that offer some information. The only problem with using the web is that information in one site is rarely complete. You'll have to go to different sites to get more information.

The first thing to remember is never use petroleum products the grease a valve inlet for oxygen. Otherwise, you'll have a new piece of jewelery imbedded deep into your skull.

If you can't find it on the Web, and no here can help you, I suggest you go to your local Library. They have these things called books that often contain tables of stuff just like this. Check it out, and make a Reference Liberian earn his/her pay.

Are you using a "poppet" valve? Or some other type of valve?

Please be specific.

I'll say pick up a valve catalog and read the application section.

Search for valve manufacturer and request/download catalog. You'll be surprise how much info is there.

Pineapple

It is usual to select the valve based on the characteristics of the fluid, its temperature and pressure, and not the other way round:

• Here is a valve. What can be done with it?
• Here is a fluid. What valve would be needed?