Flat face flange connection valves

Valve connection ends have various forms. Flat face connection is one of the commonly used connection forms. The connection code is FF. Since the entire connection surface after processing is flat face, it is easy to process and is one of the commonly used connection methods for low-pressure valves. For high pressure butterfly valves can be design with RF flange end in Cowinns company. Here we just share some knowledge for FF flange end.

Flange standards are GB/T 9113 , HG/T

20592 , GB/T 17241.6 , ASME B16.1 take the form of integral flange as an example. Different flange standards stipulate that the applicable pressure of flat face flange connection is slightly different, such as GB/T 9113-2010 whole steel in common flange Pipe flange and HG/T20592-

2009ф stipulates that the whole plane type iRPN 6 , PN 10 , PN16 .

And GB/T 17241.6-2008 integral cast iron flange and JB/T 79-

2015 integral steel pipe flanges stipulate that the applicable nominal pressure is PN2.5 , PN6 , PN10 , PN16 , PN25 , and the maximum pressure can reach PN 40 , of which GB/T 17241.6-2008 also includes Class 150 and Class 300 , American standard cast iron The pressure commonly used in valve common flat face flange connection standard ASME B6.1 is Class

125.

Since the flat face flange seal is a large plane, the contact area of ​​the gasket and the two flanges is wide when the gasket is connected to the two flanges. After the full plane is installed, the sealing surface of the sealing surface has a lower specific pressure, so the applicable nominal pressure range is narrow, PN 2.5 , PN 10 , the PN 16 is the most used applications more.

Flat face flange end gate valve and installation type