How much above main for a Gorton #2?

dkirkwood

Hi
I have 2 mains in a one pipe steam system--each main is on the long side of the house. The main currently has Hoffman No 4 vents---which i replaced only 2 years ago--but they no longer close completely--they are allowing too much steam to escape, and it is increasing the boiler add water too much.

Since I am replacing them, I read Gorton #2s are considered better valves, so I bought them.

The existing Hoffmans sit about 5" above the main. The are installed on a nipple, and 2 45 degree els coupled together that raises them to that height.

The Gortons are much larger--including the valve stem, they have a height of almost 6 inches. The space above the mains is limited due to the floor joists above.

So the question: How high must the Gortons be to function properly? One one main, there is a 2" nipple off the main tap, to which the Gorton will attach--the valve body will be 5" above that main. On the other main, there is less room--it will be attached to a one inch nipple, and the body will be about 4" off the main--note when I say valve body, I mean the body, not the stem--the stem attaches to the nipple and it is about 1.5" long, so that 1.5" is part of the measurements above.

Anyone see a problem with these clearances?

I suspect the Hoffmans failed due to grime in the pipes--so I would prefer to have the room to install a wye strainer, but to do that, I would have to offset the valves to the side of the main at least 12" on one side, and about 18" on the other, in order to get the valve to a point where other pipes/wires won't interfere with it--anyone know if offsetting the valves from the main in this manner is a problem?

Thanks for help

nicholas bonham-carter

How long are the mains from the boiler to the vent location?
The rule of thumb is one Gorton #2 for each 20 feet of 2 inch pipe. The aim for a balanced system, is to have as little resistance to the escaping air as possible, so the mains fill first with steam, and the all the radiators simultaneously.
If you provide a mounting with a circuitous route from pipe to vent, it will absorb any impact of water hammer, and the mounting height is less important.
What is your pressure?—NBC

dkirkwood

It is about 35 feet from the boiler to the vent. So should I put a T connector in an the needed fittings for 2 Gorto #2s on each main?

When you say circuitous route--do you mean a configuration where I offset the pipe to the vent off the main (e.g., use a 45 degree elbow off the main, then 12" nipple running perpendicular to the main), then another 45 elbow--and mount the vent(s) to that last elbow--is that what you meant by circuitous?

Thanks for help

nicholas bonham-carter

Yes that piping should absorb the force of any water hammer slugs coming along the mains.--NBC

Fred

Don't spend money on two Gorton #2's. Buy one Barnes and Jones Big mouth vent. It has the capacity of about two Gorton #2's, cost the same as one and is built like a tank, solid brass. Well worth the change out.

Steamhead

Those heights should be fine. What size pipe are the mains?