another question

bruce_21

Dan says in his books that an F&T trap is necessary at the end of the steam main.

This appears to be just a thermostatic trap on the end of a pipe acting like a radiator. This is a two pipe system with both a dry return for all the other radiators and this wet return for the end of the steam main and one radiator on its way back to the boiler

Do I need to change this trap?

Jamie Hall

read on...

an F&T is needed at the end of a steam main in some two pipe systems -- but not in all of them.  From what I can make out in the photos (never was much good at interpreting stuff from photos) it does look like a normaermostatic trap.  If I am correct in the big pipe being the steam main (which should be insulated!!!), and  the small pipe bieng a return, what is happening is that the small pipe from the main over to the trap plus the trap going into the return is acting like an end of main vent (it's referred to as a crossover trap in this situation).



Shouldn't have to fiddle with it at all, assuming it is working.

JStar

Yup.

That is the supply main's air vent. The thermostatic trap will prevent steam from entering the dry return. You don't have an F+T trap because the main drops down and probably goes into a wet return, creating it's own water seal, preventing steam from going into the returns.