A branch table (also called a pipe seat) provides a branch from a large diameter pipe to a small diameter pipe. The pipe on which the branch table is welded is called a main, and the pipe welded on top of the branch table is called a branch. Branch connections are available in full sizes, types, holes and pressure ratings. Materials can be stainless steel, chromium-molybdenum or other alloys.
Classification of Stub Tables
The Weldolet® butt weld stub is the most common type of branch connection. It is beveled at the end and butt-welded to a straight pipe, and is therefore considered a butt-welded fitting. The design of the butt-weld stub minimizes stress concentrations and provides overall reinforcement. Butt-weld stubs are available in STD, XS and Sch 160 pressure classes.
Socket Stubs Sockolet® have the same base as Butt Weld Stubs, but have a socket weld connection for the branch connection. The Socket Stubs are available in pressure classes 3000# and 6000#.
Threaded Stub Tables Thredolet® have the same base as Butt Weld Stub Tables, but the branch connections are threaded and do not require welding. Threaded branch tables are available in pressure classes 3000# and 6000#.
The Latrolet® is used for 45° branching. The connection to the branch pipe can be butt-welded, socket-welded or threaded.
Elbow Stubs Elbolet® are used to provide branch connections on long radius elbows or short radius elbows. The connection to the branch pipe can be butt-welded, socket-welded or threaded.
Nipolet® short pipe stubs are commonly used for valve installation and venting. Available in XS and XXS thicknesses and in lengths from 3 1/2″ to 6 1/2″ with socket or male threaded ends.
Sweepolet® is an embedded seat with a corrugated shape and integral reinforcement. Butt-welded connection to the branch pipe, commonly used for low pressure lines.
*When purchasing a branch pipe table, specify both main and branch pipe sizes and wall thickness (pressure) ratings.