80 VPV Vane Pump
Trouble Shooting for VPV “Whisper Pumps™”
Some of the most common difficulties that could be experienced in the field are listed here with potential causes and
their remedies.
TROUBLE POTENTIAL CAUSE REMEDY
Excessive 1) Coupling misalignment 1) Align the pump and motor shaft to within .006 of an inch total
pump noise indicator reading. The tighter the alignment, the quieter the
pump will be.
2). The continuous pressure is significantly 2) The pumps have been sound tuned at rated pressure. Consult
below 200 psi for 140 bar pumps, or factory or raise minimum pressure 200 psi for single stage
300 psi for 210 bar pumps. compensators in 2000 psi rated pumps, or 300 psi for 3000 psi
rated pumps.
3) Fluid in the reservoir is low and the pump 3) Fill the reservoir so that the fluid level is well above the end of the
is sucking air. suction line during all of the working cycle.
4) Restricted inlet. 4) If a suction strainer is used, check it for obstructions or dirt. We
do not recommend the use of strainers as they tend to be a
leading cause of cavitation which manifests as excessive
noise. Check also for shop rags left in the reservoir.
5) Air leak in the suction line. 5) Tighten all fittings. If it still leaks, smear grease over the joints to
locate the leak.
6) Suction line has too many elbows, or is 6) The suction line should be as short and as straight as possible to
too long. reduce the resistance to flow.
7) Air in the fluid. 7) The return line should terminate below the fluid level to prevent
splashing.
8) Suction line is too small. 8) Suction line should always be equal in size to the suction port.
Never reduce it.
9) Vane does not move freely. 9) Contamination in the fluid or a burr in the vane slot can cause a
vane to bind up. Proper filtration and/or deburring of the vane
slots is required.
10) Vane is installed incorrectly. 10) In vane pumps built up to and including SV series 62 and VPV
series 00 and A02, vanes must be mounted with the rounded
edge toward the ring. In SV series 72 and VPV series B01 and
later, the leading edge of the vanes must be oriented in the
direction of rotation. The leading edge is identified as the low
side of the vane taper.
11) A vane is missing. 11) Make sure all vane slots have a vane in them.
12) Port plates installed incorrectly. 12) Plates must be installed so that the arrows point in the same
direction as the rotational arrows on the pump body. Port plates
with ratio valves may not be installed in pump bodies prior to SV
series 74, and VPV series B01. VPV series B01 requires the use
of port plates with ratio valves for 45cc and larger pumps.
Pump will 1) Shaft rotation in the wrong direction. 1) When installing a pump, always jog the electric motor to check
not prime for proper shaft rotation. Rotation should only be clockwise (right
hand) for VPV pumps.
2) Air leak in the suction line. 2) Make sure all fittings are tight.
3) Pump is air bound. 3) Use an air bleed valve to void the pump and suction line of air.
4) Fluid level in the reservoir is too low. 4) Fill the reservoir so that the fluid level is well above the end of the
suction line.
5) Stroke limiter is turned in too far. 5) Flow should not be reduced more than 50% of maximum. Turn
CW to restrict flow, (see page 83).
6) Suction port dust plug left in place. 6) Remove plug.
Pump is 1) Contamination in the compensator. 1) Thoroughly clean the control orifices and check filtration.
unstable 2) Pressure ring is not moving properly. 2) Control piston should be checked for freedom of movement.
Pump is 1) Case drain line is installed too close to the 1) The case drain and pump inlet should be separated by a baffle
too hot pump inlet line. in the reservoir.
2) Reservoir is undersized. Rule of thumb is a 2) Add a cooler.
minimum or 2 to 3 times pump output flow.
To Next Page
Loading...
Need help?
General
