Bellow Seal Valve


F.R.I Bellow Seal Valves can be either a gate or a globe valve, designed for applications where full stem sealing (Zero Leakage) is required.

Examples of such applications are:

  • Vacuum service: where a vacuum pump is continuously extracting air from a pipeline. In this application, the Bellow Seal Valve is the only solution to prevent outside air to leak into the pipeline through the stuffing box.
  • Hazardous fluids: like chlorine, hydrogen, ammonia and others
  • Costly Fluids: in some applications, leaks need to be avoided simply because of the high cost of the fluid.
  • Environment Protection Standards.

    The bellow is the most critical component and forms the heart of the Bellow Seal Valves. The most popular stainless steel bellow material is AISI 316Ti which contain Titanium to withstand high temperatures. Alternatively, Inconel 625 improve fatigue strength and corrosion resistance as compared with stainless steel bellows. Similarly, Hastelloy C-276 offers greater corrosion resistance and fatigue strength than Inconel 625. Fatigue resistance can be improved by using a multiply bellows system and reducing the stroke length.


    Sizes: up to 36”

    Pressure class: 150# to 2500#

    Material of construction: Carbon Steel (A105 & WCB ) | Low alloys (F1-WC1 : F11-WC6 | F22-WC9) | High Alloys (F91-C12A | F92 & Stainless Steel)

    Nickle alloys: (Inconel | Monel | Hastelloy | Duplex | Super Duplex)

    Hardfacing: Stellite | Chromium Carbide

    All materials used are of 100% European origin


    Full trace-ability of all components provided with strict application of re-stamping procedures.

    F.R.I. Bellow Seal Valves are qualified fugitive emission ISO 15848-1 and can be supplied with certificate ISO 15848-2 on request.