I am looking for a certain air eliminator valve.

Sved

I have a one pipe system feeding 44 apts. The Gorton eliminator valve vents the main line quickly. Once the steam gets past the last register,the main line actually becomes a condensate return line but steam will continue to flow until it gets to the end near the boiler and the eliminator valve will close as it senses steam. However,as the steam cools down a bit, the valve will open some to keep the return line hot, thus venting some of the steam and pressure I want to go to the apts.

Does anyone make an eliminator valve that will close at say 150 and not reopen again until say 120 when the that particular heating cycle is complete?

When that valve senses 150, it is obvious that steam has reached the last riser and is feeding the apts. I don't need or want to keep the return so hot. It wastes fuel and I am trying to save fuel.

Brad White_203

Another view of what you are describing

John, I suspect that the end of the main (past the last radiator not register), is what is known as a "dry return", because it is above the waterline. Yes, it carries some condensate, in fact, all that is collected along the way, sure.

But because it is above the waterline, it is called "dry", meaning that it can carry air, steam and water for that matter. The vent at the end of this dry return is still useful for it vents air out ahead of any steam behind it.

Now, yes, you note correctly that as the steam cools and condenses, it draws a vacuum and the valve replaces it with air. Perfectly normal.

Remember, a vacuum is not pressure, it is the absence of pressure. Atmospheric pressure is higher than vacuum so it is really doing you a favor, turning a debit into a neutral condition. If the vacuum persisted, that pipe would fill with steam which would be at the expense of your radiators. We are not talking about much in either case and one hopes that pipe is insulated. Is it?

Now, if the vent is releasing steam, that itself is another issue. If not releasing steam but is closing as normal, there is not much harm that is doing for it is normal vent behavior.

If you want to save fuel, at least insulate that pipe if it is not already. Also continue to improve the things you can- insulate all piping, drop the pressure, vent the radiators, add TRV's to the radiators, etc.

Much of the heat within that dry return will be condensate-borne heat after the initial warm-up. You could always drop it below the waterline (make it a wet return) and take that steam issue out of the equation if it is that much of a concern.

My $0.02

Brad