Valves for Atmospheric Storage Tank
Large inventory, low pressure, high consequence. Tank valves manage in/out isolation, over/under-pressure breathing, water draw-off and - on flammable products - fail-safe shutoff at the nozzle.
Which valves are used on a atmospheric storage tank?
A atmospheric storage tank carries 5 characteristic valve interfaces: inlet/outlet nozzle isolation, breather / pv relief, water draw-off, recirculation / mixing, sampling. Each position, its usual valve configuration and the engineering reason are below. Typical specs are indicative — line class and project specification govern.
The Valve Interface Map
Inlet/outlet nozzle isolation
Gate Valves →Gate or resilient-seated butterfly valve
First isolation at the shell nozzle; the valve every downstream job depends on.
On flammable service, fire-safe design and often a fusible-link or remotely-operated shutoff.
Breather / PV relief
Safety & Relief Valves →Pressure/vacuum relief valve
Protects the thin shell against over-pressure on filling and vacuum collapse on emptying - sized to API 2000.
A blocked PV vent has collapsed more tanks than any other single cause.
Water draw-off
Ball Valves →Ball or plug valve
Periodic draining of settled water from the tank bottom.
Recirculation / mixing
Butterfly Valves →Butterfly valve
Isolation on mixing and recirculation nozzles.
Sampling
Ball Valves →Small-bore ball valve
Representative product sampling points at multiple levels.
Isolation Strategy
- Nozzle valve plus line blind for tank entry - a single closed valve is never entry-grade isolation
- PV vents must never be isolated while the tank is in service; maintenance requires gas-freeing or nitrogen procedures
Maintenance Notes
- PV valve pallets and seats inspected seasonally - sticking pallets from product gum are the common failure
- Exercise the nozzle valves on a schedule; a tank valve that has not moved in five years is a fitting, not a valve
Governing & Adjacent Standards
Used in these process units
Other equipment valve references
Connected Engineering
Sourcing valves for a atmospheric storage tank?
Send your equipment datasheet or line list — we supply the full valve set (Gate Valves, Safety & Relief Valves, Ball Valves, Butterfly Valves) with certification, in one PO.