Main Air Valves Question

maggy

I have a ThermoFlow GSA 175, 175000BTU steam boiler with two mains out of it. One main is 43 ft feeding 7 radiators and the other main is 33 ft feeding 5 radiators. I have a Gorton #1 at the end of each main and the heat is working ok. My question is will I benefit anything if I upgrade to Gorton #2's. And should I put more than one, or should I just leave as it is....Thanks for any replies

Hap_Hazzard

What's the system pressure like?

Does your boiler cycle on pressure (i.e. does it turn on and off several times each heating cycle before the thermostat is satisfied)? In particular, does the boiler shut down momentarily before the radiators even get hot? This would be a sign of inadequate venting. But if this is not the case, and your system pressure is less than 2 psi and everything is perfectly balanced, I'd say leave it alone.



But if you want to increase the venting, you might try

a. putting a Gorton #2 on the longer main and 3 Gorton #1s on the shorter one.

b. putting 2 Gorton #2s on the longer main and a Gorton #2 and 2 Gorton #1s on the shorter one.



Both of these give you a 4:3 venting capacity ratio to go with the 4:3 volume ratio, and both allow you to keep using the two #1s (assuming they're healthy). If the mains are 2" pipe I think the first option would be adequate.

nicholas bonham-carter

improving venting

can you hear any sounds from your radiator vents, either a start-up [pressure], or at shutdown [vacuum]?

if you can fit them is, then i would add a gorton 2 to each main venting location. the gorton 2 is cheaper per cu ft. capacity, and although you may have more venting than you need, you can never have too much.

rather than figure out what the volume of the pipes, and boiler steam chest is, i prefer to have the same amount of resistance of venting on each dry return, so that the steam will fill the main pipes first, and then start up the risers and takeoff's simultaneously. a 0-3 psi gauge on the same pigtail will let you know when you have the lowest possible resistance to the escaping air [back-pressure].--nbc