Direct injection of liquid into the high-pressure side of the double or single seal is called "flushing". Generally, pumps should be flushed, especially light hydrocarbon pumps.
1. Flush to dissipate heat. The heat generated by the liquid seal must be controlled. This can be achieved by flushing the sealed cavity with liquid to remove heat and control the temperature rise.
2. Lower the liquid temperature. In some cases, the liquid temperature is too high to affect the sealing performance. In such cases, the temperature must be lowered to improve the performance of the liquid.
3. Change the pressure in the sealed chamber. In some cases, it is necessary to increase or decrease the pressure in the sealed chamber to improve performance. This can be achieved by suppressing evaporation or reducing the thermal load on the seal.
4. Clean process liquid. If the process liquid contains inappropriate solid particles or contaminants, the liquid in the sealed cavity needs to be cleaned. In extreme cases, it may be necessary to provide clean liquid from outside the sealing system.
5. Control the atmosphere side of the seal. Because process liquids are in contact with the atmosphere, they may dry out, crystallize, or coke. It is very important to prevent interaction with the atmosphere so as not to adversely affect the sealing performance.
Classification of Machine Seal Washing Solutions
◆Single Seals
PLAN 01 (single end face self-washing)
PLAN 02 (jacket cooling and heating)
PLAN 11 (self flushing)
PLAN 13 (backwashing)
PLAN 14 (forward + reverse flushing)
PLAN 21 (self-flushing with cooling)
PLAN 23 (internal flushing with circulation sleeve)
PLAN 31 (self-flushing with suspension separator)
PLAN 32 (external flushing)
PLAN 41 (self-flushing with suspension separator and heat exchanger)
◆Dual Seals
PLAN 52 (Tandem seal with pressureless buffer tank)
PLAN 53A (double end face seal with pressure seal fluid)
PLAN 53B (double end face seal with forced circulation of sealing liquid)
PLAN 53C (Double end seal with booster tank)
PLAN 54 (Double end face seal with external sealing liquid)
◆Quench Seals
PLAN 62 (external flushing or rapid cooling to prevent accumulation of solid particles on the sealing surface)
PLAN 65 (with float level switch to measure seal leakage)
◆Gas Seals
PLAN 72 (Tandem dry gas seal using isolated nitrogen for volatile media)
PLAN 74 (double end face dry gas seal)
PLAN 75 (used in series dry gas seal for non-volatile media)
PLAN 76 (Tandem dry gas seal with externally-lead sealed gas)
