 |  ccessible for inspection and repair. Whenever possible, a trap should be located where it can be reached for testing and maintenance without the need of a ladder or man-lift, and without having to crawl under a piece of equipment or lie on the floor. This may not always be possible, but if traps are easier to test, chances are they will be tested more frequently. |
 |  elow the drip point. If the condensate is elevated to the trap, there is a loss of the differential pressure available for trap operation. This can result in inconsistent drainage of the heat exchanger or distribution line. It may also lead to excessive condensate retention and possible problems with freezing, water hammer and corrosion. |
 |  lose to the drip point. The vertical piping connecting the drip point to the trap is called the drip leg. Long drip legs can cause drainage problems because condensate can cool significantly before it can be discharged. Extremely short drip legs can cause problems as well, because they provide little static head to drain themselves when the steam is shut off. The horizontal piping connecting the drip leg to the trap is called the runout. The length of the runout should be minimized to prevent a pressure drop upstream of the trap. Such a pressure drop reduces the differential pressure at the trap, decreasing trap capacity. |
 |  rain each drip point with a single trap. This rule for trapping should never be broken under any circumstances. Short-circuiting occurs when the condensate outlets from two heat exchange units are connected. Short-circuiting is likely whenever the drip points of two heat exchangers are drained with one trap, even if the two units appear to be identical. Any differences in condensing rates will result in a variance in the steam pressure drops of the two units. The condensate from the unit with the lower pressure drop will prevent air and condensate coming from the other unit from reaching the trap. The difference in condensing rates can seem insignificant, such as when there is uneven airflow across the face of two adjacent coils in the same plenum, but should be taken seriously. |
