Hot Tip #13 – Steam Traps
“Drain each drip point with a separate 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, but it is not insignificant and must be taken seriously. This means that every iron chest should have a separate trap. If it is a split chest design ironer then each half will have a separate trap.
I was troubleshooting an ironer problem over the phone several years ago where a GM was insistent that one of his ironers was not large enough to dry his goods. Maintenance assured me that the trapping system was working fine. Not able to solve his problem over the phone, I jumped on a plane to find an eight-roll Hypro iron with a single trap for all rolls!