Normally this type of mechanical seal flushing plan is used for the fluid contain more amount of suspended solid materials and low vapour pressure fluids. In this mechanical seal flushing plan, the flushing fluid is pumped in to the seal chamber from an external clean source. Seal chamber heat removal Process and solids removal from seal chamber Increase seal chamber pressure and fluid vapour margin. The injection fluid must be compatible with process fluid. In which the pump manufacture use throat bushing sized to hold pressure or maintain flow velocity of the flushing fluid. To restrict dirty process fluid enter in to the seal chamber, injection flow rate is maintained 1.5 ksc or 1.5 psi greater than the pump discharge pressure in the case of single stage pump. Where in the case of multistage pump the injection pressure will be vary with the pressure developed by the end impeller (that is after that impeller mechanical seal is mounted).
API Flushing Plan 32
- Used on dirty or contaminated fluids, paper pulp etc..,
- High temperature service
- Regularly monitor control system for closed valves or signs of plugging
- By using of external pump system for injecting flushing fluid, thereby we spend additional energy for the whole system.