Bypass is used to prevent vapor lock in vertical multistage pumps.
Vapors are discharged from the upper part of the working chamber of the pump through a thin copper tube into the suction pipeline.
When pumping hot liquids (water, alcohols, ethers, etc.) whose temperature approaches the boiling point,
a vapor-air lock is formed in the upper part of the pump, which leads to a drop in performance and pressure
of the pump unit In addition, in this mode of operation, the mechanical shaft seal
dry running mode, which inevitably leads to failure.
