Mechanical seal (mechanical seal) of the basic concepts

Mechanical seal (mechanical seal) of the basic concepts: mechanical seal (mechanical seal) is defined as at least one rotation axis perpendicular to face pressure in the fluid and elastic compensation mechanism (or magnetic) and under the effect of maintaining cooperation with the secondary seal affixed relative sliding of the merger constitute a device to prevent fluid leakage. Elastic loading mechanism and the secondary seal is a metallic bellows mechanical seal which we call metal bellows seal. In the light seal, there are used as an aid to the rubber bellows seals, rubber bellows stretch limited, generally need to meet the load supported by elastic springs.

Mechanical seal consists of:
There are four main parts. a. main components: the rotating ring and stationary ring. b. Auxiliary Seal: Seal (with O-, X-shaped, U-shaped, wedge-shaped, rectangular flexible graphite, PTFE-coated rubber O-ring, etc.). c. elastic compensation mechanism: spring, push the ring. d. Transmission Parts: Kei seat shells and key or a variety of screws.
[Cartridge mechanical seals]
Cartridge mechanical seal
cable tray accessories, wire cable baskets, cable tray supports
Mechanical seal should pay attention to the problem:
1. Installation Notes
a. the installation to be very careful to avoid bias arising from the installation
(1) on the gland should be carried out after the coupling alignment, the bolts should be evenly supported to prevent deflection end gland, check with a feeler points, the error is not greater than 0.05 mm.
(2) Check the gland and the shaft or sleeve diameter with the gap (ie concentric), four weeks should be uniform, with a feeler points tolerance is not greater than 0.01 mm.

b. The amount of compression according to the provisions of the spring, does not allow too large or too small phenomenon requires error 2.00 mm. Face than the pressure increase over the General Assembly, the other speed face wear. Too small will cause less than the pressure seal and can not play a role.
c. ring installed, it will ring after the spring pressure to automatically bounce back.
2. Disassembly Notes
a. In the installation, carefully remove the mechanical seal, is strictly prohibited the use of hand-hammer and flat shovel to avoid damaging the sealing elements. If the scale demolition of no less than should be cleaned before demolition.
b. If both ends of the pump mechanical seal, in the assembly, disassembly process of mutual care, to prevent trade-off.
c. mechanical seal on the run-off, loosen the seal gland where the case is moved, the movement ring parts must be replaced, should continue to be used to re-tighten. Because loose track after the friction will change in the original operation, the sealing contact surface is very easily destroyed.
Mechanical seal running and maintenance issues:
1 Before you start work and precautions
a. a comprehensive inspection of mechanical seals and ancillary equipment and piping installation is complete, compliance with technical requirements.
b. mechanical seal for hydrostatic testing before the start, check the mechanical seal for signs of leakage. If the leak more, should find out the reason for trying to eliminate. If still ineffective, should be demolished and re-check the installation. Hydrostatic test pressure used is generally 2 to 3 kg / sq cm.
c. Press the pump rotation to drive cars, check whether the light evenly. Such as disk drive difficult or not moving, you should check whether the error size of the assembly, installation is reasonable.

2 Installation and decommissioning
a. before the start should be kept sealed cavity filled with liquid. Solidification of the medium for transmission, the application of steam to melt sealed chamber heated to medium. Disk drive before starting to prevent the sudden start caused by a soft ring fragmentation.
b. For use outside the seal pump mechanical seal oil system, seal oil system should start. After stopping the last stop seal oil system.
c. heat pump does not immediately stop after the outage seal oil and seal the cavity cooling water, seal should be 80 degrees at the oil temperature dropped to below, we can stop the cooling water to avoid damage to the seal parts.
3 running
a. If the pump starts slight leakage, should be observed for some time. If continuous operation 4 hours, leakage is still not reduced, the pump should stop checking.
b. pump operating pressure should be stable, the pressure fluctuation is less than 1 kg / square centimeter.
c. pump in operation, should avoid the phenomenon of taking the time to avoid dry friction and sealing the sealing surface damage.
d. Always check the seals. Operation, when the leakage exceeds the standard, heavy oil is not more than 5 drops / min, light oil is not greater than 10 / min, 2-3 days, still no improvement if the trend should stop the pump bolt check seals.