Not vulnerable to water hammer. Upon startup, air, gas, and cool condensate freely vented. Will dump live steam if cool air surrounds trap, May need insulation for proper operation. If failure rates are high, dirt, corrosion, water hammering, and freezing are the usual causes. Dirt can be from a variety of causes, and cannot always be avoided.
Strainers help prevent dirt from damaging traps.
Take immediate action to discover where corrosive elements are entering the system. Convective and radiative heat losses from steam traps can cost hundreds of dollars, depending on the size and temperatures of the trap and surrounding air. If condensate pressure is less than atmospheric pressure, the visual method is useless. Abnormally warm boiler room. Condensate pump water seal failing prematurely.