Emergency Vents
Large-capacity relief devices that open under abnormal overpressure conditions to protect tank integrity.
Manufactured in Vadodara, Gujarat, India by Pressure and Flow Control Industries since 1975.
Overview
Emergency vents are sized for abnormal events that a standard breather valve is not intended to handle — most commonly external fire exposure, where rapid vaporization can quickly overwhelm normal relief capacity. They provide the large, fast-opening relief area needed to keep tank internal pressure within safe limits during such events.
PRECON® Emergency Pressure Relief Valves (Model PFCI/EPRV/2051) are recommended for large above-ground storage tanks in addition to the normal venting capacity provided by breather valves and flame arresters, as per API 2000. They stay tightly sealed in normal conditions and open only when the set pressure is reached, releasing the excess vapour.
How It Works
Under normal operation the vent stays fully seated and weathertight. When internal pressure exceeds the emergency set point, the full vent area opens rapidly to relieve large vapor volumes, then re-seats once pressure returns to normal.
Applications
- Fire-exposure overpressure protection on storage tanks
- Backup relief alongside primary breather valves
- Tanks handling volatile or high-vapor-pressure products
Choose the Right Configuration
PRECON® Emergency Vents come in three operating types, chosen by tank size and the set pressure required. All three share the same body materials, PTFE diaphragms and flanged end connections.
Guide Operated
A weight-loaded pallet on a vertical central guide, which keeps the seat aligned and lifts the pallet straight up for maximum flow. The standard choice for low set pressures: sizes 6" to 30", set pressures 40 to 400 mm WC, with an aluminium pallet up to 80 mm WC and stainless steel above.
Download CatalogueSpring Loaded
An economical solution for emergency venting on higher-pressure tanks where a weight-loaded design is impractical. The spring gives a tighter seal at higher operating pressures and reseats the pallet immediately after the overpressure is released. Stainless steel pallet; 6" to 16" for set pressures of 1050 to 8000 mm WC, and 18" to 24" for 800 to 8000 mm WC.
Download CatalogueHinge Operated
Designed for higher settings with a weight-loaded pallet. The whole pallet assembly lifts on its hinge, giving clear access for tank inspection with no dismantling or gasket replacement, so the vent is back in service without expensive manpower. Stainless steel pallet; 6" to 12" for set pressures of 100 to 1000 mm WC, and 14" to 24" for 100 to 800 mm WC.
Download Catalogue