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7. Gas-Ballast Valve
A gas ballast valve is provided on the side of the PKS. (Ref. DWG. Fig. 4 ~ 6)
When condensable gases such as steam or solvents, etc. are pumped, compressed
gases may be condensed and mixed into the pump oil.
Such gases circulate inside the pump and may effect both the ultimate pressure
and also shorten the life of the pump's shaft seals and bearings. Consequently
the life of the pump itself will be shortened. But in this pump, when a
condensable gas is pumped, such a gas can be discharged out of the pump through
the exhaust valve without condensing it into the pump oil, by opening the gas
ballast valve after the pump temperature increases sufficiently. (When gases
other than condensable gases are pumped, operate the pump with the gas ballast
valve closed).
8. Operation
8.1 Pump start
Recheck the prescribed installation once more. Operate the pump in
accordance with the following procedures to obtain the best performance of the
pump.
1) Close the vacuum valve [A] (as shown in Fig. 2) and open the leak valve [B].
2) Turn the motor-switch on.
3) Close the leak valve [B] when the pump is rotating at a constant speed.
4) Check the oil-feeding solenoid valve for proper operation.
Note: If the pump does not rotate smoothly, do the following;
1) Check the power supply
2) Check the charged oil level. If the problem still persists, contact
ULVAC or ULVAC's distributor.
