Description
The FIG 351S & 748A is an integrated flame arrester and pressure vacuum vent for atmospheric storage tanks. It prevents flames from entering the tank’s vapor space while controlling internal pressure. This 2″” assembly is ideal for hydrocarbon service, ensuring tank safety during normal operation and protecting against external ignition.
Features
- Combined flame arrester (351S) and pressure vacuum vent (748A) in one assembly
- Stainless steel arrester plates for reliable flame barrier performance
- Cast iron body and cover (351S); aluminum body and hood (748A)
- Brass poppets and arrester grid housing for corrosion resistance
- 30-mesh stainless steel screens on the 748A
- BSP threaded variant (351SB) available for international installations
- Optional dryer-equipped 748A models available
- Pressure settings from 2 oz/sq.in. up to 16 oz/sq.in.
Applications
- Aboveground atmospheric storage tanks handling hydrocarbon fuels (e.g., gasoline)
- Tanks built and tested in accordance with UL 142, NFPA 30 & 30A, and API 650
- Shop-fabricated atmospheric storage tank installations
Restrictions & Warnings
- Not for use with: Acetylene, carbon disulfide, ethylene oxide, or hydrogen gases
- Service: Sized for normal hydrocarbon flames (e.g., gasoline in air) only
- Maintenance: Monthly inspection required; immediate inspection during freezing conditions
- Safety: Blocked airways can cause excessive pressure/vacuum buildup and structural tank damage
- Operational: Tank must not be filled or unloaded unless vents are confirmed fully operational
- Sizing: Size vents per NFPA 30 (2018) §21.4.3
