Answer / www.islamqa.com

#"Cv" for valve is known as: valve sizing coefficient or
valve flow coefficient

#It refers to " how many gallons per minute can pass
through a fully open valve under diffrential pressure of 1
PSI "

#Cv is a unitless value and by getting it's value we can
get the valve size in inch from tables.

#Cv is got from calculations using s/w provided by
manufacturer as we have many parameters affect its value,
and Cv value is critical as it affects valve size which
leads us - if wrong - to oversized valve or undersized
valve, which harm the process.

#Cv - as mentioned - is got from calculations using s/w,
but it has a basic formula for gas service and liquid
service.

#For liquid service:

Q = Cv (DP/ROH)^.5, ROH IS SPECIFIC GRAVITY

#For gas service:

Q = 963 Cv (DP(P1+P2)/ROH*T)^.5, T is gas temperature in
Rankin

Regards,

Ahmed Sabry
Control and Instrumentation Engineer
GPC - General Petroleum Company
ahmedsabry.online@gmail.com
CELL.: 00 2 0121367310

Answer / bhavesh

wecan seeing value of (cv)means cooficient of valve and as
per desined use pipeline in short we can define control
valve size as per desining requriment.

Answer / faiyaz

class 150 class 300 class 600 class 900 class 1500 its size of valve according to the size oil and gas and water will be flow

Answer / ashok

BY SEEING BODY SIZE AND NAME PLATE

Answer / venkatesh j

we can seeing valve size and valve tubing and valve colour

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