Orifice plate Sizing

[GenevaMech]

6 foot diameter pipe carrying high temp gas at high flow. could be as high as 25000 ft^3/s. need to size orifice plate to read about 100 in H2O or more of pressure change across plate. for some reason my calcs keep saying pressure drop will be around 10 in H2O even if beta is .5!! i know something is wrong. any helpful sites or tips?

thanks and god bless engineers

 

[JLSeagull]

If really six-foot diamteter, an orifice plate is the WRONG FLOW ELEMENT for a NPS 72 pipe. For large pipe consider other flow element technologies such as transit time ultrasonic or thermal mass flow.

 

[GenevaMech]

haha that's what i said, but this is what the company wants.

 

[JLSeagull]

An old control valve sales manager used to advise his peddlers, "Tell them they are wrong twice - then sell it to them."

 

[DLite30]

yea, this seems slightly ridiculous...but anyway, I show that a 36" orifice in 72" pipe will flow just over 2,100 MMSCFD at 140F (0.6 SG natural gas) at 700 psig with 100"H20 psid.

http://tinyurl.com/3yrgplf