Steam Trap Safety Issues

When steam traps cause a backup of condensate in a steam main, the condensate is carried along with the steam. This lowers steam quality and increases the potential for water hammer. Not only will energy be wasted, but equipment can also be destroyed. Water hammer occurs as slugs of water are picked up at high speeds in a poorly designed steam main, in pipe coils, or where there is a lift after a steam trap. In some systems, the flow may be at 120 feet per second, which is about 82 mph.

As the slug of condensate is carried along the steam line, it can reach an obstruction, such as a bend or a valve, where it is suddenly stopped. The effect of this impact can be imagined. It is important to note that the damaging effect of water hammer is due to steam velocity, not steam pressure. It can be as damaging in low-pressure systems as it can in high. This can actually produce a safety hazard, as the force of water hammer can blow out a valve or a strainer. Condensate in a steam system can be very destructive. It can cause valves to become wiredrawn and unable to hold temperatures as required. Little beads of water in a steam line can eventually cut any small orifices the steam normally passes through. Wiredrawing will eventually cut enough of the metal in a valve seat that it prevents adequate closure, producing leakage in the system.