The ZJY Series consists of compact Roots vacuum booster pumps equipped with an integrated bypass valve for differential-pressure protection. Two synchronized, non-contact figure-eight-shaped rotors provide high pumping capacity while the internal bypass valve limits excessive pressure differential during initial evacuation and high-gas-load conditions. This allows the booster and backing pump to start at approximately the same time in properly configured vacuum systems, helping shorten evacuation time. With a compact footprint, low operating noise and nominal pumping speeds from 252 to 4,320 m³/h (70–1,200 L/s), the ZJY Series is particularly suitable for industrial systems requiring high pumping capacity at low inlet pressures.
Working Principle
Two synchronized figure-eight-shaped rotors rotate in opposite directions inside the pump housing without contacting each other or the chamber wall. Gas entering the inlet is trapped between the rotors and housing and transported toward the discharge side. The integrated bypass valve responds to the pressure differential across the booster. When the differential pressure exceeds the specified setting, the valve opens and recirculates part of the gas from the discharge side to the inlet side, limiting booster load. As system pressure decreases and the differential pressure falls, the bypass valve closes progressively and the booster delivers its full pumping capacity.
Key Features
Pumping speeds are nominal values at 50 Hz. 1 L/s = 3.6 m³/h.
Bypass Valve ΔP: Differential pressure at which the integrated bypass valve operates to limit excessive pressure differential across the Roots booster.
*Ultimate pressure depends on the backing pump, vacuum-system configuration and operating conditions. ZJY Series Roots vacuum boosters are designed to operate with a suitable backing pump.
Typical Applications
high-capacity evacuation for industrial drying processes
vacuum furnaces, heat treatment and sintering systems
pre-evacuation and booster stages for coating equipment
vacuum drying and treatment of transformers, capacitors and electrical components
vacuum distillation, concentration and drying with suitable backing pumps
compact booster systems requiring fast evacuation and simplified start-up