Legend
- V. vent (if required)
- FI. flow indicator
- FIL. coalescing filter used in barrier gas feeding
- FSH. high flow switch
- GBI. buffer gas inlet (plugged)
- GBO. barrier gas outlet (normally closed) used only to depressurize the stuffing box
- PI. pressure indicator
- PCV. pressure control valve, sets the pressure above the process pressure of the inner seal
- PSL. low pressure switch
- 1. Buffer gas panel (feeding unit)
- 2. Vendor
- 3. Purchaser
- 4. If required
Barrier gas installation. Externally supplied barrier gas is used to positively prevent process fluid from leaking into the atmosphere. Pressure of the barrier gas is higher than the medium pressure on the technological process side of the inner seal. Venting of the gland box may be required prior to start-up and operation, to avoid the collection of gas in the pump.
Barrier gas installation operating according to Plan 74 comprises a power supply unit equipped with appropriate connectors and valves and control and measuring equipment. This installation is used with double gas-lubricated seals.
APPLICATION EXAMPLE
