Control Valve

No.

Not without a lot more details. If you cannot supply us with sufficient information about the process the valve is supposed to control, how can we help?

Are you a :

Browser?

Student?

Valve salesman?

Process engineer?

Valve technician?

Manager?

Just curious?

I am a Design Engineer and i am not good in control valves.

Actually,for one project,i have received many calculation sheet and quotations from vendors so i just want to know what are the main things in calculation sheet and quotation which i should check?

This is a quite complex subject. Some basics include:

1) Compatibility of valve parts with the fluid.
2) Pressure and temperature conditions.
3) Basic valve type (piston, globe, ball, diaphragm, butterfly, needle, etc.)
4) Flow coefficient (C_v or K_v, depending on local custom).

As for calculations, most will revolve around item (4).

I am a Design Engineer and i am not good in control valves.

Actually,for one project,i have received many calculation sheet and quotations from vendors so i just want to know what are the main things in calculation sheet and quotation which i should check?

Is it possible for you to give data for some examples? The field is too wide for one-size-fits-all generalities.

Various control valve manufacturer literature often has good information, often in an engineering appendix to their catalog. If you are receiving quotations from vendors, ask them for such data. Good vendors will be helpful with this.

In calculation sheet,This calculation sheet provided by samson and there is 6 main columns

These are factors given from Valve vendor.My question is which factor should i check and there is any thumb rule for review of calculation sheet?

Can you tell us what the valve is supposed to do?

This is Level control valve.

Oh, God.

I was hoping for something like, "This is Level control valve", it is used in the xxxxx industry for controlling the level of xxxxx liquid in a xxxx plant, etc.

I think we have failure to communicate.

?

I am a Design Engineer and i am not good in control valves.

Actually,for one project,i have received many calculation sheet and quotations from vendors so i just want to know what are the main things in calculation sheet and quotation which i should check?

Hi Ankur,

Control Valve selection is (as Lyn has suggested) a complex field. In my experience use the valve supplier's expertise. For the correct valve selection, you need to decide on the minimum operating pressure drop for given flow duty point, and the max pressure drop for given flow duty point. From this the valve supplier will calculate the correct Cv, and operating range of the valve. You can do this yourself, but the operating characteristics of the valves can be very particular to each manufacturer. Hence, I would work closely with the valve suppliers, develop a working relationship, so you can trust in their experience.

Having said that, you don't exactly need a high performance control valve, a Level control valve simply needs to open and close when the level in the tank triggers a change. This is sometimes done with electrical signal from level transmitter, but is more often done with a float valve (when open allows diaphragm valve to open, and when float is closed on high level, causes the diaphragm valve to close).

So a level control valve, is significantly simpler than a true control valve.

To confirm the suitability of the valve, I would check the following ...

1. Check the flow through the valve is acceptable.

2. Check the pressure drop at that flow is acceptable.

3. Check the pressure rating of the valve suits your needs.

4. Check the material of construction (including all wetted parts) is compatible with the process fluid (at the process temperature, pH etc).

5. Review the rest of the information, if you don't understand any of it - ask the manufacturer that sent it (they are paid to assist you).

Hope this helps.

Anthony

Do you know what the valve is supposed to do?

You select a control valve after carefully specifying the requirements for the valve.

To do this, you would need to know what industry the valve will be used in. The processes and chemicals involved in them. If you cannot do this, you are lost.

In my opinion, you are lost.

Review of the "calculation sheet" will depend on much more than you have given us, also.

Your refusal to provide useful information will never result in a satisfactory answer to your VERY GENERAL question.

Yes, if there is someone in the area that can act as a Mentor.