TESTING STEAM TRAP OPERATION.

Several methods used for evaluating trap operation - including pyrometers, thermometers, pellets, and crayons that melt at predetermined temperatures - have little or no usefulness. Only when the steam pressure is very low (in the order of 2 to 5 psi as, for example, in a low-pressure steam heating system) are temperature measurements useful in trap testing. In a low-pressure heating system, thermostatic traps that discharge at temperatures below 212 F are generally used. Although there may be pressure in the return line, the temperature of the condenasate will be below 212 F because there is no flashing. In a vacuum system, however, flashing may occur and temperature measurements are of no value. Testing techniques are included for thermostatic traps, bucket traps, thermodynamic traps, impulse traps, and float-thermostatic traps.