Vane pumps use GRAPHITAR vanes, liners and rotors. For best performance, GRAPHITAR vanes are machined for a close tolerance fit between vane and rotor, a radiused contact edge and an exact length. Vanes should be specified up to the minimum length of the rotor. No allowance need be made for swelling of the vane in service. GRAPHITAR’s high degree of stability in any pumped medium will maintain the close clearance originally built into the assembly. Centrifugal force is sufficient in most applications to maintain vane contact with the liner. Some slow speed pumps may require the use of a spring, hydraulic or pneumatic pressure behind the vane.

Inlet and outlet ports are usually moulded into GRAPHITAR end plates to avoid radial machining on the pump liner. A commercial lap will give the bearing surface adequate flatness as it will seat itself against the rotating parts in operation. Liners are finished to the same length as the rotor by lapping both ends to a high degree of flatness and parallelism.

Successful Usage

GRAPHITAR parts have also been successfully used in reciprocating pumps. Pistons, Piston rings and valve plates of GRAPHITAR give longer life and positive sealing in applications where lubrication problems prohibit the use of other materials. Tensile loads on the piston can be met by running the rod through the piston and compressing the GRAPHITAR member between two metal washers. For applications where positive pressure is maintained on the piston, an open ball joint has given excellent performance. Piston rings can be gapped or segmented , with either butt or overlap joints.
Properly designed and assembled GRAPHITAR pump components can be expected to show virtually no wear after a very short run in period, provided their mating surfaces are hard and smooth.  

The Parts We Offer

  • Pump vanes
  • Carbon rotors
  • Compressor pistons and piston rings
  • Consumer and automotive pump assemblies
  • Pump liners and valve plates
GRAPHITAR parts from US Graphite have many successful uses within a wide range of pump applications within the consumer automotive and industrial markets.