STEAM TRAPS

Miscellaneous Mechanical Components DOE-HDBK-1018/2-93 STEAM TRAPS STEAM TRAPS Steam traps are installed in steam lines to drain condensate from the lines without allowing the escape of steam. There are many designs of steam traps for high and low pressure use. EO 1.14 STATE the purpose and general operation of a steam trap. EO 1.15 IDENTIFY the following types of steam traps: a. Ball float steam trap c. Bucket steam trap b. Bellow steam trap d. Impulse steam trap General Operation In general, a steam trap consists of a Figure 16 Ball Float Steam Trap valve and a device or arrangement that causes the valve to open and close as necessary to drain the condensate from piping without allowing the escape of steam. Steam traps are installed at low points in the system or machinery to be drained. Some types of steam traps that are used in DOE facilities are described in this chapter. Ball Float Steam Trap A ball float steam trap is illustrated in Figure 16. The valve of this trap is connected to the float in such a way that the valve opens when the float rises. When the trap is in operation, the steam and any water that may be mixed with it flows into the float chamber. The water, being heavier than the steam, falls to the bottom of the trap, causing the water level to rise. As the water level rises, it lifts the float; thus lifting the valve plug and opening the valve. The condensate drains out and the float moves down to a lower position, closing the valve before the condensate level gets low enough to allow steam to escape. The condensate that passes out of the trap is returned to the feed system. Rev. 0 ME-05 Page 35