Welch’s belt-driven vacuum pumps are available with an ultimate pressure of 1x10-4 mbar with a comprehensive pumping speed ranging between 1.3 m³/h and 15 m³/h.


ChemStar® belt-driven vacuum pumps are designed to tolerate harsh chemical contamination. That’s why vital pump parts are corrosion resistant. The oil capacity is large for excellent dilution of contaminants. Oil is fed to the pump from the top of the reservoir allowing sludge to settle without compromising lubrication. The recommended lubricant ("Gold Oil") is a synthetic oil designed to reduce chemically active sites. Use the nitrogen purge to drive elimination of corrosive gases. Chemical reactions affecting the pump oil are lessened by low pump operating temperatures, a result of slow pump rotation and reduced friction. PTFE surfaces, fluorocarbon gaskets and seals, Nitrogen purge to cool and degas oil. A gas ballast valve is included for use when pumping condensable vapors.

Welch also provides the system add-ons that further protect your pump and your environment. Select the equipment that augments your vacuum system needs – traps, oil mist eliminators, and system components.

ChemStar® are delivered with Gold Oil, motor overload protection, gas ballast valve, hinge clamp ring, centering ring, hose connector and ready to use after oil filling.

Welch vacuum pump oil is specifically formulated for the unique needs of vacuum pumps. Use of non-Welch vacuum pump oil voids any performance claims and product warranties.

•In Duoseal belt driven rotary vane pumps, use Welch Duoseal or Welch Gold Oil

•In CRVpro rotary vane pumps use Welch premium or Welch gold oil

•In Chemstar belt driven rotary vane pumps use Welch gold oil