selection guide for conrol valve

can anyone give me selection guide for control valve or the steps how to select control valve generally and the standard that mentioned this steps

shkoko2000,

not trying to slam you, but you are asking a question that is
hard to answer.

your question needs refining so we can help.
is the valve pneumatic, hydraulic, ball valve.
what is the application?
what is the speed you need to operate at if you are using a cylinder?
what is the desired pressure of the cylinder?
and what do you want to happen when the valve operates in the "A" position, is off, is operating in the "B" position?

you can google solenoid valves, valve basics.

regards,
james

i want selection of control valves(seat and plug) with i/p to operate as LCV or PCV

The Fisher Control Valve Handbook, now in its 4th edition, is considered a classic on process control valves.

http://www.documentation.emersonprocess.com/groups/public/documents/book/cvh99.pdf

Emerson also publishes a valve sizing calculation white paper using traditional methods:
http://www.documentation.emersonprocess.com/groups/public/documents/reference/d351798x012_11.pdf

To actually order a valve you'll need to specify its Cv, which requires a knowledge of the process (how much pressure do you want the valve to drop?) and

- process medium (maybe viscosity)
- specific gravity at operating temp
- operating temperature span
- operating pressure span, inlet pressure, outlet pressure (delta P)
- flow rate

What the valve needs to be:
style - 2 way/3 way
valve body material
trim material
flow characteristic needed: linear, equal percentage, quick opening
body line size
end connections: threaded/flanged/
leakage requirement
bonnet
packing material
spring range
actuator actuation - pneumatic? electric?
actuator action in the event of signal failure: fail open/closed/last
line pressure against which the valve actuator must operate and close against
Accessories
- positioner or I/P only?
- position feedback?
- proof of closure/open switches?
- gauges ?
- EXP ?
- input? 4-20mA? Fieldbus?
- Handwheel?
- airset?
- purge or drain connections?
- solenoid valve?