The weldolet has a bevelled end to butt weld to the branch pipe. (which will also have a bevelled end), whereas the sockolet has a socket into which a plain end. branch pipe is inserted, then fillet welded together. Pipe olets. Weldolet is the type of fitting used to create a branch with the smaller size of main pipe.

Sweepolet is used for large size branch connection. It provides smooth flow transition from run pipe to branch pipe. Sweepolet is used in piping header and pressure vessel when smooth flow transition is necessary and standard tee cannot be used.