Operation, Priming the pump, Using the pump – Crystal HydraulicPump User Manual

Page 5: To establish a zero pressure reference

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Operation

3

HydraulicPump Operation Manual

Operation

PRIMING THE PUMP

1

Put a small amount of fl uid in the Reservoir; enough to cover the bleed-off valve hole in the

bottom of the reservoir.

The easiest way to fi ll the Reservoir is to remove the Vent Plug, and use the fl uid bottle to squirt

fl uid into the Reservoir.

2

Turn the variable volume handle clockwise until it stops turning.

3

Open the Bleed-off Valve by turning it counter-clockwise, then squeeze the Handle.

Fluid and trapped air should circulate out of the Bleed-off Valve hole back into the Reservoir.

4

Squeeze the Handle repeatedly until no air is seen coming out of the Bleed-off Valve hole.

5

Fill the Reservoir, in prepation for use.

Note:

We recommend that you keep the pump primed.

USING THE PUMP

1

Shut-off the Bleed-off Valve.

2

Squeeze the handle until fl uid is seen in the NPT port.

3

Open the Variable Volume Handle counter-clockwise until it stops.

4

Attach a pressure standard to the NPT port.

5

Remove the CPF Plug and connect your CPF hose.

We suggest that you squeeze the pump handle to fi ll the hose with fl uid, prior to connecting

the other end of the hose to the instrument to be calibrated.

6

Squeeze the pump handle to generate 20–30 psi and loosen the CPF fi tting connection at the

end of the hose to bleed air from the system through the CPF weep / bleed hole.

7

Repeat until no air escapes.

This minimizes the volume of air you will need to compress to achieve your desired pressure. In

fact, the less air you have in your system, the better the pump will perform.

TO ESTABLISH A ZERO PRESSURE REFERENCE

1

Check that the pump at the same elevation as the device being tested

2

Open the Bleed-off Valve.

3

Close the Bleed-off Valve, and repeatedly squeeze the Handle until you are close to, but not

greater than, your desired pressure point.

4

Use the the Variable Volume Handle to adjust the pressure to precisely your desired pressure.

The pressure may initially appear to be unstable, and dropping. This is usually due to either a

small amount of expansion of the hose under pressure, and/or residual air or gas dissolving into

the hydraulic fl uid. If there are no leaks, both of these eff ects will diminish until the pressure is

stable. Of course, very high resolution pressure calibrators will detect this eff ect better than low

cost mechanical gauges.

Bleed-off Valve

Variable Volume Handle

Vent Plug

Reservoir

Handle

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