Legend
- F. flushing inlet
- V. vent
- LBI. barrier liquid inlet
- LBO. barrier liquid outlet
- LI. level indicator
- LSL. low level switch
- PI. pressure indicator
- TI. temperature indicator
- 1. Barrier liquid refill
- 2. If required
- 3. Piston accumulator
Application of external piping feeding liquid to the barrier system in order to supply clear liquid to the external seal of the double system. Circulation is forced and maintained by an internal pumping ring. Barrier liquid pressure (ensured by the piston accumulator connected with the gland box) is higher than the sealed process pressure. Air- or water-cooled heat exchanger carries the heat away from the circulation system. Characteristics of the barrier liquid should be defined, to keep the operating conditions of the slide ring faces of the seal stable. Solution typical for double seals.