vacuum condensate lift fittings

garynavo

Anybody know if these are still made? I'm looking at a project in California that needs them.

nicholas bonham-carter

Can you describe the situation a bit more, as there may be an alternative solution.--NBC

Pumpguy

I've checked around, and have been told manufactured lift fittings have not been on the market for maybe 50 years or more. I only recall seeing one installation that had manufactured cast iron lift fittings, and that went in before WW 2.

These can be easily made up from common pipe fittings; either screwed or welded up.

The most important one is at the bottom of the lift. This is basically an inverted P trap. This allows the upstream horizontal run to totally drain. The upper loop over is only necessary if the downstream run is longer than 10 feet.

The actual lift pipe should be smaller in diameter. This increases the velocity in the lift and is more efficient.

Please keep in mind that lift fittings should only be used out in the system, and never just ahead of a vacuum condensate pump's receiver tank.

When a lift is required at the inlet of the vacuum condensate pump's receiver tank, an auxiliary accumulator tank with float switch should be used. This is really a large volume lift fitting with a float switch and air vent pipe with pressure vent check valve.

With this arrangement, the condensate flows by gravity to the auxiliary accumulator tank. If the vacuum pump is running, condensate immediately gets lifted up to the vacuum pump's receiver.

If the vacuum pump is not running, the aux tank will fill until the float switch trips, turning on the vacuum pump to make the lift.

If a lift fitting is used in lieu of an auxiliary accumulator tank, it will be necessary to run the vacuum pump continuous to keep the lower returns drained of condensate.

In this arrangement, when the vacuum pump shuts off, the pressure differential needed to make the lift is lost, and the lower returns will fill with condensate until the vacuum pump is started again. This will also cause a water seal on the system, preventing air from venting off to atmosphere.

Pumpguy

That should read.........P trap, not inverted P trap. Sorry.

gerry gill

thats a great little write up on how things work Pumpguy , much appreciated.

Pumpguy

I can't tell you how many times I see this stuff piped wrong. As with what I read here about boiler installations, It seems like people don't read installation instructions, or do and just don't care.