Book - School of Science and Technology

220 Pumps and other auxiliary equipmentCondensate handling equipmentWhen steam has given up its latent content in heating equipment of any type, thecondensate remains at the temperature of the steam and it would be inexcusably wastefulto discharge it to drain since it might well represent 20% or so of the energy input to theboiler plant. The condensate must, however, be removed as soon as it is formed, in orderto prevent water-logging, and returned to the boiler plant for re-evaporation.Steam trapsAt the exit point of the heating equipment it is necessary to introduce a device which willallow condensate to pass but not steam: this is a function fulfilled by the steam trap. Thereare various types of trap and these fall into three broad categories, identified by the meansadopted to distinguish and separate condensate from live steam, as follows:. Mechanical,incorporatingOpen top bucketInverted bucketBall float.. Thermostatic,with various elementsBalanced pressureLiquid expansionBi-metallic.Open top bucket Inverted bucket Ball floatMechanical type trapsBalanced pressureBi-metallicThermostatic type trapsThermodynamic trap(with strainer)Figure 8.18 Types of steam trap (various manufacturers)