A dummy leg or trunnion is a piece of pipe welded to a straight, bend, or elbow in a piping system instead of a structural member. They are used on sections of pipe as support stands. They are best used when little to no movement is foreseen in the system and primarily prevent against sagging or extra stress to other piping sections. The ‘dummy’ support gets its name from the fact that the pipe does not conduct the flow of anything, however it can be vital for keeping a section of the system in place.
Depending on the load and the available structural steel member one dummy support may be used or two dummy supports may be used. Trunnion lengths should be kept as short as possible to minimize the bending and stresses at the weld joint on the pipe. Trunnion supports may be used with reinforcing pipe saddles for heavier pipe loads to distribute the pipe load over a larger pipe wall area.
Dummy legs and trunnion supports are often made of the same or slightly smaller-sized pipe of the piping system.
We can fabricate and supply dummy legs and trunnion supports to specification and cope for field installation.