When building a pipeline, the length of the pipes used are not always known. By manufacturing the pipe separate from the flange plate, the welders can cut the pipe to length and weld a flange plate in place to join the pipes at any needed length. The plates can also be welded to the pipe on a slight bias, allowing two pipes to be joined that may not be precisely lined up.
There are many different styles of flange plates that are used for different purposes. The blind plate acts as a cover or cap for a pipe and is used to seal or block off a pipe. The slip-on style of plate allows the plate to be slid onto a pipe and then welded in place. Using the socket weld-style of plate on the ends of two pipes allow them to be easily connected and disconnected.
Flange plates with chamfers and bevels are used to assist in lining up two pipes which are out of alignment. Plates with a studding outlet are plates that have studs inserted around the plate in place of bolt holes. This type of plate allows the pipes to be joined by sliding one flange plate over the studs on a second flange plate and then nuts are tightened to secure the two.
America Series:Class 150 ,Class 300, Class 600, Class 900A ,Class 1500,Class 2500.
Flange Facing Types
America Series:Flat face(FF),Raised face(RF),Tongue(T),Groove(G),Female(F),Male(M),Ring type joints face(RJ/RTJ)
Europe Series:Type A(Flat Face),Type B(Raised Face),Type C(Tongue),Type D(Groove),Type E(Spigot),Type F(Recess),Type G(O-Ring Spigot),Type H(O-Ring Groove)