Main advantages of this seal type are:
- Lubrication of the seal faces from atmospheric side and therefore prevention of dry running even when there is insufficient liquid at process side
- Prevention of deposits at the atmospheric side of the seal (crystals)
- Dilute leaking liquid
API Plan 62: During operation, the flushing liquid enters the seal box from below and flushes spring, shaft sleeve and static seal ring from the atmospheric side. It takes diluted chemical residue out.
The system is designed to work unpressurized but some pressure may be used! Clean water or water with glycol is used as external medium but caution needs to be taken for process liquids that may react with water. The recommended flow is appr. 25 l/h. Pressure is maximum 3 Bar.