Posted by S Crook on December 24, 2000 at 12:38:47:
In Reply to: Re: pressuretrol/vaporstat posted by Larry Shoots on December 16, 2000 at 12:05:24:
: : We have a two pipe steam system which has a Honeywell 404A pressuretrol(subtractive differential)with an operating range of 3lbs. and up. From what I have read, the system should have a pressuretrol which will allow an operating range of .5 cut-in and maximum of 2 cut-out. I have also read that a Honeywell vaporstat(L408A1132) could be used. Would this vaporstat be okay for my system and what are the operating range settings?
: What is a vaporstat? It sounds like something I would be interested in. I am looking for a steam valve that allows a certain amount of steam to enter the room. Does a vaporstat perform this function?
A Honeywell Vaporstat is a pressure switch like a pressuretrol but with a range of either 0-1 psi or 0-4 psi depending on the model (compare to 1/2 to 9 psi for typical p-trols. They will let you set the pressure much lower than the typical minimum of OFF at 1.5psi and subtractive diff of 1psi for ON at 0.5 psi w/ pressuretrol. e.g ON at 4 oz (1/4 psi) OFF at 12 oz (3/4 psi) will work like a charm on most systems, some will run at even lowerr pressures. The name of the game is to stay below 2 psi at absolute most, below 1.5 psi ideally.