Threaded back check valves for one directional LPG/NH3 flow

Threaded back check valves are one-way valves that protect container contents from escaping if piping or fittings accidentally break. Frequently they are found in gas installations where there is a requirement for a high, single directional flow.

Product description

As back check valves provide a one-way flow security functionality, they are ideal for installation in pipelines flowing into pressure tanks and pump discharge lines as they will close off if the flow-direction changes or stops.

icon 3 squares in front of eachother symbolising material


Body: Brass, cadmium plated steel, carbon steel, stainless steel
Disc: Brass, cadmium plated steel
Stem: Brass, stainless steel, cadmium plated steel
Spring: Stainless steel, carbon steel
Seat disc: Synthetic rubber
Guide: Carbon steel, stainless steel
Poppet: Stainless steel

icon a gear with lines going up down left and right symbolising specifications


Gas types: LPG (Propane, Butane), NH3 (Ammonia, Anhydrous Ammonia)
Connections: Thread
Type: NPT
Operating pressure: Up to 27.5 bar (400 psi)
Internal pressure: Up to 131 bar (1900 psi)
Temperature range: -45˚C to +148˚C (-50˚F to +300˚F)
Sizes and range: 1/2" to 3"
Series: 33146 Series, 3176 Series, A3186, A3187S, A3196, A3276BC, A6586D, A6586D, A3400L4, A3400L6, 302 model, 143 model, 51 model and 50 model 
Standards: UL listed, CE-PED

*Materials and specifications are subject to generalisation. Our experienced people are ready to help you find the correct fit for your application. 

icon a magnifying glass over a gear symbolising features


  • Heavy-duty construction for long life endurance
  • Positive seal of soft seat valves due to synthetic rubber seat disc
  • Faster flow rate provided by swing-away checks
  • Low pressure due to generous flow channels
  • Faster filling of bulk tanks
  • Available in steel, brass and stainless-steel

Did you know?

MAKEEN Gas Equipment can provide a threaded type with a threaded flange connection available in 1-½" to 8"

Alternative products

  • Flanged back check valve

    Back check valves (flanged)

    These one-directional valves close off if the flow direction changes or flow stops. They keep the contents of a container from escaping if the piping or fittings accidentally break.

    See our Back check valves (flanged)

Get in touch!

Whether you already know what you need, or you would like the opinion of an expert, we are always ready to help you out.