UW1981
Mechanical
- Oct 25, 2005
- 38
Does anybody know why API STD 526 limits the pressure on some orifice/flange combinations. As an example, a 600#/150# 4X6 "L" orifice constructed out of carbon steel has a pressure limitation of 1,000 psig at 100 F (Table 10), though a 600#/150# 3X4 "K" at 100 F is rated at the full flange rating of 1,480 psig. There are some manufacturers that "deviate" from these pressure limitations outlined in 526, but I was hoping to learn the reason for the limitation before we accept valves that exceed those limitations.
