The emergency vent is an auxiliary to a free vent. It acts to relieve excess internal pressure created by overheating, fire and over-pumping etc.
OPW 202F Emergency Pressure Relief Vent

These vents meet the requirements of API 2000 code as stipulated in AS 1940.
Features & Benefits
- Lightweight Construction – Allows for safe, easy installation on large aboveground tanks.
- Spring-Loaded, O-Ring Sealed Cover with Teflon-Coated Seat – Ensures smooth, vapor-tight sealing surface and reliable service life.
- Full-Bore, High-Capacity Upward Venting – Enables smaller diameter vents with higher venting capacity to be used on ASTs when compared to weighted, mushroom-style vents.
- Aluminum Cover and Body with Stainless Steel Components – Corrosion-resistant construction to protect expensive finish or epoxy coatings on ASTs.
- Alerts Tank Operators of Possible Venting Problems – When the emergency vent is actuated, the lid remains open for inspection until manually reset. The actuation of the emergency vent indicates abnormal excessive pressure build-up in the tank due to either a blockage in the normal tank vent or in the event of a rapid expansion of vapors, possibly from a fire.
- 3-Point Vent Shear System – Ensures the vent safely opens every time, even if non-OPW replacement parts are utilized. Shear Pin breaks at 2.5 psi (0.17 bar), Break Link breaks at 3.5 psi (0.24 bar), and Bar breaks at 6.5 psi (0.44 bar).
- UL Listed - To satisfy Third Party accreditation requirements of many jurisdictions
Spare Parts:
1 | H04869RE | Break Link |
2 | H06475RE | Rivet |
3 | H04981M | Cotter Pin |
4 | H04928 | Parts S/A |
5 | H04929M | Screw |
6 | C01288I | Bar |
7 | H04871M | Break Pin |
8 | C01289M | Gasket |
9 | H04873M | O-Ring |
10 | H06449RE | Rivet |