Cracking Pressure

[rbashiz]

Hi,

I am supposed to order a check valve to be used on a subsea pig reciver. the check valve is to be used when dewatering the pipeline when receiving the pigs.

the valve is 4" on a 16" line. what would the cracking pressure be?

Thanks,

Leni

 

[chemebabak]

rbashiz,

Why do you need to know the cracking pressure? Is this a low pressure application?

Unless this is a low pressure operation, you should not worry about the cracking pressure. Many check valve manufacturers offer low cracking pressure check valves, but I do not see how pipeline dewatering would require low cracking pressure.

The cracking pressure of most standard check valves are in the 3-5 psig range. In any case, if I needed to know that kind of information, I would ask the valve vendor. The cracking pressure is different for each type of valve. They have all this data for each valve.

 

[brubakerj]

Consider the poppet weight divided by the area of the orifice. Crane's Tech Paper 410 has some formulas for minimum flow (not sure how they are derived).