Installation of Steam Traps

However carefully a steam trap may be designed, made and chosen, unless it is correctly installed, maximum efficiency is impossible. 

First, make sure that the trap will continue to function when installed by keeping out pipe scale, jointing and packing with a strainer.  Strainers are cheap insurance against trap maintenance and are far superior to dirt pockets which are never cleaned out anyway. 

Second, remember that the trap has yet to be designed that will bring the condensate to it.  Provision must be made to collect the water and lead it to the trap. 

How often is a trap installed like this!  A 6" main with a 1/2" drain connection and the trap conveniently placed for maintenance but too far away from the drain point for efficient service.  The end view (Diagram A) shows how easily condensate is carried past the drain point giving the trap no opportunity to release it. 

To drain a main efficiently, size a drip pocket equal to the size of the steam main with pipes up to 4".  Then 1/2 the main diameter size, up to and larger than 4", but not less than 4".  Therefore, a 4" and 6" main pipe size would still have a 4" diameter drip leg.  To create a differential pressure across the trap, the leg should be at least 12" in length (see Diagram "A").  Then fit the strainer and trap as near to the drain point as possible if a mechanical trap is used or about 2-3 ft. away if a thermostatic trap is chosen. 

This will make sure that no condensate runs past the trap and that the trap will not be delayed in discharging the water that collects.

Contributed by Bruce Gorelick, Enercheck Systems, Inc.