PV Breather Valves
The Series 8300 range of Breather Valves minimise vapour losses from storage tanks during operations whilst preventing internal pressure & vacuum conditions from exceeding the tank design limits. Hence both product & vessels are protected as well as tank environmental conditions.
DESIGN FEATURES
COMBINED UNITS
Series 8300 Pressure & Vacuum Breather Valves can be fitted in combination with Series 8350 Flame Arresters.
Note – This type of installation reduces valve flow capacities and thus special sizing calculations are applicable.
CHEMICAL SERVICE
Series 8300 Pressure & Vacuum Breather Valves can be supplied in a range of alternative materials for chemical and/or cryogenic services and can be used with air dryers fitted at the vacuum inlet port, to protect those products which could be adversely affected by normal atmospheric air.
It is suitable for wide range of services in the petroleum, chemical and related industries for land tankages only.
LOW BLOW-DOWN
Blow-down is the difference between opening and closing pressures.
The floating diaphragm operation ensures that blow-down is minimised to 10% for pressure relief and 10-15% for vacuum relief.
LOW LEAKAGE
Capability of the resilient diaphragm to wrap around the edge of the pallet seat. The high ratio of seating force to seating area provides a tight seal.
As the pressure or vacuum rises, the relevant pallet begins to lift, but the diaphragm wrap around at the edge of the seat maintains a good seal.
As the pressure or vacuum continues to rise, the pallet lifts further, but the diaphragm naturally assumes a good seal.
When pressure or vacuum reaches the set conditions, the pallet opens fully.
