Vacuum Generation - WIKA CPP30 Betriebsanleitung

5. Commissioning, operation
After increasing the pressure, the value displayed can drop slightly again
for about 30 seconds.
The causes can be thermodynamic effects, the hose connection and the
seals.
Readjust the pressure using the fine adjustment valve. If pressure
continues to drop, check the measuring circuit for leak tightness.
Reducing the pressure for new pressure range
▶
Turn the fine adjustment valve until the new, desired pressure is reached.
▶
Turn clockwise in order to increase the pressure.
▶
Turn anticlockwise in order to reduce the pressure.
Reducing the pressure to 0 bar [0 psi]
1. Turn the fine adjustment valve anticlockwise.
2. Carefully open the pressure relief valve by turning it anticlockwise no more than once.
⇒
Pressure is reduced and there is no pressure on the hand test pump.
Do not disassemble the reference pressure measuring instrument or the
test item until the pressure relief valve is open and there is no pressure in
the test pump.

5.5 Vacuum generation

1. Before vacuum can be generated, the switching valve may have to be actuated
(see label on the pump). Use a pen or a small screwdriver for this. The cover of the
switching valve is intended to prevent unintentional actuation.
▶
Make sure the drain valve is not completely closed.
▶
Ensure that the knurled nut and counter nut are adjusted so that the spring or
sleeve visible above the counter nut has just a little play when the pump handles
are pressed together.
2. Screw in the fine adjustment valve clockwise, until a slight stop is felt.
3. Carefully screw the pressure relief valve by turning it clockwise, until the valve closes.
⇒
There is no "hard stop" to be felt.
4. Using the pump handles, carefully and slowly pump until the maximum vacuum is
reached.
5. Use the fine adjustment valve, until the desired vacuum is reached exactly; max.
-0.95 bar [-28 inHg].
▶
Turn clockwise in order to reduce the vacuum (increase pressure).
▶
Turn anticlockwise in order to increase the vacuum.
WIKA operating instructions, model CPP30
EN
15