In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
There is this job. It is a one-pipe steam system. We installed a new boiler and lost our A dimension. So we installed a condensate tank with traps at the end of the main and at every drip. We installed air vents on the outlet side of each trap. All of the traps and air vents are about 25 inches above the boiler's water line.
When we started it up, condensate was stacking in the returns. It was not flowing to the condensate tank fast enough. The condensate would build and build until water started squirting out of every air vent. The air vents were not breaking the vacuum quick enough. So, I raised each air vent about 2 feet above the outlet of the traps. Presto. This solved everything.
I thought that the return was open to the atmosphere so the highest the condensate would get would be the inlet to the tank. And when the tank got full it would pump the water into the boiler. Does anyone know why the air vents needed to be raised in order to break the vacuum?