Rotor pump overpressure protection function
Benefit: Automatic pressure regulation protects the pump from failure and mechanical problems.
How it works:
The "spring" and "piston" of the exhaust packing normally send pressure to the part of the pump that is in contact with the liquid.
When the pressure inside the pump (or the part in contact with the fluid) is higher than the pressure exerted by the spring, the pressure difference pushes the exhaust packing upward in the opposite direction from the part in contact with the fluid. This causes the fluid to flow backwards through bypasses A and B, which inhibits the increase in pressure inside the pump (in the part in contact with the fluid).
The vent cap includes the adjusting bolt, lock nut, cap nut, spring retainer, coil spring, guide bushing, piston, piston o-ring, vent packing, and sleeve cap.