1. How many types of seals are commonly used in pumps?
There are two types, dynamic seal and static seal.
2. What is the basis for choosing seals for pumps used in chemical production?
According to the process conditions, working pressure and medium corrosion, the rotation speed is selected.
3. What are the types of flat gasket seals?
1) Non-metallic gasket seal;
2) Non-metal and metal composite gasket seal;
3) Metal pad seal.
4. What are the main causes of gasket leakage?
1) leakage caused by design;
a Improper selection of flange and flange sealing surface;
b Improper selection of gaskets;
c. Improper selection of flange and bolt materials;
2) leakage caused by the manufacture, installation, and operation;
a The machining accuracy of flanges and gaskets does not meet the technical requirements;
b. When tightening the bolts, the operation is improper, causing the gasket to deviate;
c The face of the flange seal is clean and free of impurities.
5. What is the working principle of the floating ring seal?
The floating ring seal is based on the throttling effect produced in the narrow gap between the shaft and the floating ring and injects sealing oil higher than the gas pressure in the gap to achieve the purpose of sealing the gas.
6. What causes the increased leakage of the floating ring seal?
1) The floating ring is used for a long time, and the normal wear and tear increases the gap;
2) The surface of the bushing of the floating ring hole is rough, the precision is low, and the gap increases due to short-term wear;
3) Improper assembly causes deflection, and the centering accessories fall off, causing the oil to flow out from other gaps, which increases the leakage;
7. What are the common types of dynamic seals?
Cup seals, ring seals, spiral seals, pneumatic seals, hydraulic seals, centrifugal seals, packing seals, labyrinth seals, mechanical seals, etc.
8. What are the main factors affecting sealing?
1) the quality of the seal itself,
2) process operating conditions,
3) Assembly and installation accuracy,
4) The accuracy of the host itself,
5) Sealing auxiliary system
9. What is the inspection standard of the dynamic seal leakage point?
1) The sealing point of the packing shall not exceed 15 drops per minute;
2) The mechanical seal point is not allowed to leak at the beginning, and no more than 15 drops per minute at the end;
3) The gear oil pump is allowed to leak slightly, no more than 1 drop per minute;
4) Various oil injectors are allowed to leak slightly, no more than 1 drop per minute.