Vacuum pump use and general fault treatment

2019/5/28

Before use, should first read carefully shangcheng product specifications, unpacking should check the quality of shipment. Collect the spare parts and technical documents, remove the vent protection parts. Installation, wiring and steering test as required.
An auxiliary method for judging steering. Put the sheath upside down on the pump port. If it is sucked up after the pump is started, it is in the forward direction; if it is blown down, it is in the reverse direction. Normal sound is forward, abnormal sound is reverse.
If equipped with inflatable solenoid valve in the pump mouth, generally should be installed horizontally, and at the same time with the pump action. Vacuum pump oil is recommended according to the manual. Note that ester vacuum pump oil is not allowed to mix with mineral oil vacuum pump oil and other oils. Only after strict cleaning can ester vacuum pump oil be replaced.
Check the ultimate pressure of the pump with the compressed mercury vacuum gauge as the standard. The full pressure gauge should pay attention to the matching calibration and backup comparison between the gauge and the regulator. It is recommended to install a ball valve between the regulator and the pump under test. Close the valve in case of emergency to extend the regulatory service time.
Shangcheng vacuum pump maintenance
L. First of all, we need to know the type, characteristics and current condition of the pump. Understand the operation requirements and determine the repair target. Be prepared with testing tools before carrying out maintenance.
2. Fault diagnosis and diagnosis. Good judgment saves trouble. Verify the diagnosis.
3, troubleshooting, simple after complex, easy after difficult. Do not disassemble without disassembling. To reduce new damage caused by lack of special tools and improper operation, reduce position change and run-in time. Generally speaking, the spliced rotor is not removable, otherwise the shape and position tolerance will not be maintained, the rotor will be scrapped.
4, toxic and harmful, corrosive pumps, users should be asked to clean, and inform the necessary protective measures, to protect the health of maintenance personnel.

Vacuum pump fault classification
It is recommended to divide the faults into operation faults and performance faults.
The operation failure may include the pump does not turn, the pump temperature is too high, the oil leakage, the water leakage, the high power exceeds the standard and so on.
The performance failure may include the limit pressure, the limit full pressure, the extraction efficiency, the noise, the injection oil, the gas ballast performance and so on not to be up to the standard or cannot meet the requirements.
1. Examples of fault judgment and diagnosis
2, the pump can disk move without turning. The cause may be coupling failure; Belt slip; Motor wiring error; Motor damage; The power is out.
3, can not dish or dish up very heavy, the reason can be because the starting pump temperature is too low, pump oil viscosity is too high; Design and manufacture reasons for stopping pump return too much oil. Too much stop and return oil caused by too high oil level (too much refueling, or condensation of water vapor in the pump, or condensation of water flow back to the pump in the exhaust pipe); There are foreign bodies in the pump (welding slag and oxide in the intake pipe; Spinner spring and other pump parts of the debris; The rotary vane is stuck in deformation; Bite occurs (copper sleeve, rotor, middle wall, pump cover, stator, bearing).
4, the pump temperature is too high. Means that the high oil temperature measured near the low level exhaust valve exceeds the specified value in the operation manual. Because the pump temperature rise will make the pump oil viscosity significantly decreased, and the saturated vapor pressure of pump oil increased, so that the ultimate pressure of the pump increased and pumping efficiency decreased; Make rubber parts easy to age; Thermal expansion reduces the operating clearance, especially the thickness direction of some non-metallic rotary plates and the clearance of copper sleeve inner hole, which affects the reliability of pump operation. The reasons for the high pump temperature can be that the environment temperature of the pump is too high, the inlet temperature is too high, the inlet cooling device fails, and the inlet pressure of the pump is too high for long-term continuous operation. Water cooling pump cooling water shortage, circulating water design effect is not good; Temperature control water regulating valve failure.
5. Oil leakage. Can occur in the shaft seal, oil tank and pump parts of the sealing surface, oil plug, oil standard, oil hole, stator parts and support through hole connection, air ballast valve (such as 2X-8) and other parts. It can be caused by aging of seals, improper installation, damage and failure, uneven surface, impurities, roughness and loose casting. If the pump after the return of oil, oil will enter the gas valve, not open the gas valve may leak.
Homemade rubber pad, must use oil resistant rubber, according to the original design shape, sealing surface is too big pressure will not be tight oil leakage.
6. Water leakage can occur in water pipe joints, cover plane of water jacket, screw plug of water drain hole, water drain valve, etc., water jacket drilling, casting defects, freezing crack, and water leakage may also be caused.
7. High power exceeds standard. Can be caused by long-term continuous inlet pressure is too high, exhaust pressure is too high, debris into the occurrence of bite, pump temperature is too high, rotary plate and other cooperation gap is too small, voltage is too high, pump fluid back into the pump too much, will damage the motor. Long term continuous operation near high power should be avoided as far as possible. If there are deposits on the surface, disassemble and remove them regularly.
8, the limit pressure is not up to standard.
Can be caused by external leakage, internal leakage, oil hole blockage, pump oil quality or pollution deterioration, water vapor and other condensable substances, instrument distortion, pump operation is not normal.
More leakage, exhaust port can see white steam. There are many bubbles at the oil mark. You can feel the exhaust pressure on the exhaust port. There are many bubbles in the oil surface of low level exhaust valve. Power will increase. At this point, the first check whether the gas ballast valve has been closed. Since every new pump is tested at the pump mouth, if there is leakage, the pump mouth, pipes, valves and containers should be checked one by one. External shaft seal failure, oil cup without oil, oil hole head leakage can also cause external leakage. Internal leakage can be caused by the movement gap in the pump, exhaust valve seat plane, exhaust valve sealing surface, internal shaft seal, pump cover plane, intake pipe, air ballast valve seal. Wear, corrosion and bite will increase the operating clearance. When the oil hole is blocked, open the oil hole to listen to, the noise of the pump will be relatively light, in the case of a good oil tank seal, if the hand on the exhaust port has the feeling of being sucked, exhaust valve may fail.
9. Noise. Pump structure design, motor and pump bearing noise, rotating vane and other moving parts smooth, too much oil intake, fan, transmission parts produced by noise, large air intake, open air ballast operation, oil baffle plate and other pump parts loose, the installation of unequal vibration, will affect pump noise.
10, spray oil. To prevent oil in the oil box of the oil return hole size, location, the condition of seal, oil baffle plate design, installation, vent part of mist reduction device, the oil and gas separator cap, the oil level the height, the size of the input, will affect the fuel injection pump, the pump door open atmosphere, straight league pump outlet air velocity can be as high as 30 m/s, blown away when the oil level, oil in the cycle of pump and air flow out of the oil will test all measures to prevent injection.