The air pressure instrument of the vacuum aluminum brazing is within the service range of the validity period. If the valve of the vacuum pipe has air leakage, the valve will be replaced.
Through inspection, the clearance between the rotor and the rotor of the Roots pump and between the rotor and the inner wall of the pump cavity is within the allowable range,
and the gear wear is very small, so it is unnecessary to replace it,
If the bearing is seriously worn, the bearing is replaced. The shaft head seal ring of the roots pump leaked oil. The shaft head seal ring was replaced and the lubricating oil at both ends of the roots pump was replaced.
After the maintenance of the Roots pumps, there is no air leakage at the leak detection seal. The ultimate vacuum of the Roots pump can reach 3 × 10-2Pa。
vacuum aluminum brazing valve
Through the external inspection of the furnace body and vacuum extraction system of the vacuum aluminum brazing,
it was found that the main valve stem seal, the pre-extraction valve, the vent valve, the pneumatic ball valve, and the furnace door seal all had different degrees of air leakage.
After disassembly and inspection,
it was found that the valve stem seal of the main valve and the sealing ring of the furnace door big ring were seriously aged, cracked, and had air leakage,
so the corresponding sealing ring was replaced.
When replacing the main valve stem seal ring, considering the influence of high temperature here,
the seal ring is simple aging, so the material selected is fluoro rubber.
Fluorine rubber is a very good sealing material with high-temperature resistance and various media resistance.
It has a small amount of gas discharge and has unparalleled superior performance over other sealing materials, thus providing the necessary guarantee for the sealing here.
At the same time, it was found that the sealing wear of the pre-extraction valve core, vent valve,
pneumatic ball valve stem, and valve core was very serious, so the three valves were replaced.
thermocouple of vacuum aluminum brazing
3, When detecting the leakage at the metal head of the thermocouple, due to the relatively long reaction time of leakage detection,
if there is a very small leakage point near the metal head of the thermocouple, it is particularly easy to misjudge.
For this, a special method is adopted: first, wrap the seal of the coupling wire with a plastic bag, and then pass helium into the plastic bag for leak detection.
Through the above method, it was found that there was gas leakage at the seal of the thermocouple itself, so a new thermocouple was replaced.