What is a dummy leg? Hazards?

• A. A non-adjustable pipe support welded to strengthen a vulnerable point; hazards include pipe failure, corrosion, and loss of primary containment (LOPC)
• B. A flexible hanger; hazards include movement
• C. A short pipe for venting; hazards include leaks
• D. A test stub; hazards include miscalibration

Answer: (A)

A dummy leg is a short, non-adjustable pipe piece welded into a line to reinforce and stiffen a vulnerable point in a piping system. It’s meant to provide fixed support and help keep the pipe from bending or moving at a critical spot, especially where there may be stress, expansion, or loads acting on the line.

Because it’s a permanent, welded addition, problems can arise if the weld or the leg itself deteriorates. A failed or corroded leg can lead to a leak or rupture, and since the containment of the process fluid is compromised, there’s a risk of loss of primary containment (LOPC). The fixed nature of the leg also means it can introduce stress concentrations or traps for moisture and corrosive agents if not properly designed and maintained.

This fits best because it describes a permanent reinforcement item, distinct from a flexible hanger (which would allow motion), a venting short pipe (whose purpose is to vent, not reinforce), or a test stub (used for testing or calibration, not structural support).