NV C-1A Boilers Practice Questions - Nevada C-1A Boilers Contractor Examination Exam

So the pump can pull a vacuum on the boiler and boil the water. Because the tank is the point of no pressure change; pumping away raises pressure in the circuit and improves air control. So the relief valve will open on every start. Because NFPA 54 requires all pumps to discharge into the gas vent.