The key to maintain vacuum oil filling equipment is to judge faults.

The main point of repairing vacuum equipment is to judge faults. Vacuum can not be pumped up, there may be several reasons, we must find out what is the reason, is the vacuum injection equipment pumping capacity is not enough or high leakage rate; or both. At this time, we should observe and record patiently and find out the faults. For example, the same time to evacuate, and the vacuum is low, at this time, close the high-pressure valve, such as the vacuum gauge pointer drops quickly, in most cases the vacuum chamber leak, this time should be detected first. If the vacuum gauge pointer drops very slowly, most cases is the vacuum unit pumping capacity is not enough, then the focus will be on finding the vacuum pump and valve problems, see where there is leakage, or diffusion pump oil is polluted, oxidation, etc., or the front pipeline seal is not good, pump oil is not enough; or pump oil emulsion, shaft Sealing oil leakage, valve damage and other failures.

The most troublesome problem for users is the leak detection rate. Leakage is divided into internal leakage and external leakage; leakage is better to detect, and internal leakage is harder to handle. The larger leak point can be detected by flame method. According to the principle that the air flow can make the flame deviate, vacuum is pumped first, and the leak point can be found if the flame is deviated from the leak point by candle or lighter. We can use the homemade leak detector to detect the leak within the working range of the rotary vane pump. Now we have produced ZHC.1 instrument. The leak detector is equipped with ZJ.2 ionization gauge and regulated by the suction port of rotary pump. If the diffusion pump unit, the leakage rate of l0Pa can be detected.

Small leaks and micro-leaks of vacuum oil injection equipment are difficult to detect. The common method is to use the ionization tube sensitive to certain gases in high vacuum, such as acetone or ethanol, inject acetone or ethanol into suspicious places with medical syringes. When the ionization meter is injected to the leak point, the needle will swing obviously. In this way must have patience, must wait until the ionometer's indication is stable, that is, the vacuum unit's pumping capacity and leakage balance, and then injection. It is best to repeat the leak several times. ZHC-1 instrument can also use the above method to detect leakage, the difference is that the ZHC-1 instrument can detect leakage within the working range of rotary vane pump, and not afraid of exposure to the atmosphere.

Leakage occurs mostly on equipment with water cooling sleeves, and no doubt is found in the leakage. But there are the following phenomena: the pumping speed of the mechanical pump is obviously low, the vacuum indicator value is low, the mechanical pump oil is quickly emulsified, the iron-based parts in the vacuum chamber are obviously corroded, with the above conditions can be basically determined to have internal leakage. There is a 25kg medium frequency furnace, 2X-70 rotary vane pump and 150 Roots pump together can only pump l0Pa, 150 Roots pump function is not shown, no leakage, but with the mechanical pump oil quickly emulsified, vacuum chamber iron base obvious rust conditions, disintegration equipment clean up with cooling water method It was found that the lid was leaking. The rest is to find out the leak. First clean up the inner wall, then pass through the cooling water to see if there is no wetting point.