
What is a wafer check valve?
A wafer check valve is a non-return valve in wafer (lug-less) design that prevents backflow of media in pipelines. When flow pressure is sufficient, the hinged disc inside opens. As soon as pressure drops or flow reverses, the disc closes automatically — by gravity or by a return spring. Compared to a disc check valve, the swing check valve suits larger nominal sizes and higher flow rates. The compact wafer design to EN 1092-1 saves installation space compared to full-flanged check valves.
Check valve stainless steel — RK100 and RK101 ranges
Fergo stocks two ranges as check valve stainless steel:
- RK100: single-plate check valve, body and disc in stainless steel 1.4408, seal EPDM, NBR or metallic, with or without spring return, PN10/16/25/40 to EN 1092-1 Form B
- RK101: stainless steel check valve with FKM/Viton seat seal, body and disc in 1.4408, PN16, temperature range −10 °C to +180 °C
For steel pipelines with lower corrosion requirements the RK100 is also available in galvanised carbon steel 1.0619 and carbon steel 1.0460.

Plastic check valve — PVC-U and PP-H for aggressive media
The Fergo plastic check valve suits chemically aggressive media where metallic materials reach their limits. Two plastic options are available:
- PVC-U: for acids, alkalis, chlorine and wastewater at temperatures up to +60 °C — economical solution for water treatment, electroplating and pool technology
- PP-H (polypropylene): for aggressive chemicals at higher temperatures up to +100 °C — proven in chemical processing, exhaust air systems and flue gas scrubbers
Both plastic check valves are manufactured in wafer design and fit the same flange connections to EN 1092-1 as the stainless steel and carbon steel versions. For PFA-lined systems Fergo also stocks check valves in ductile iron GGG40.3+PFA.
Wafer check valve — technical data
- Nominal size: DN32 to DN400
- Connection: flange PN6, PN10, PN16, PN25, PN40, ANSI Class 125/150/300 to EN 1092-1 Form B
- Body (metal): stainless steel 1.4408, galvanised steel 1.0619, steel 1.0460, ductile iron GGG40.3+PFA
- Body (plastic): PVC-U, PP-H (polypropylene)
- Disc: stainless steel 1.4408/1.4581, galvanised steel 1.0619, PVC-U or PP-H (plastic body)
- Screws: stainless steel 1.4401
- Seat seal: EPDM, NBR, FKM (Viton), PTFE, metallic
- Spring: stainless steel 1.4571 (optional, spring return)
- Operating pressure: max. 16 bar (depending on DN and material; plastic derated by medium and temperature)
- Temperature: −10 °C to +180 °C (stainless steel/steel), up to +60 °C (PVC-U), up to +100 °C (PP-H)
- Conformity:EU Pressure Equipment Directive 2014/68/EU
Seal material — EPDM, NBR, FKM, PTFE or metallic
| Seal | Typical media | Temperature |
|---|---|---|
| EPDM | water, air, dilute acids | −40 °C to +120 °C |
| NBR | mineral oils, fuels, hydraulic fluids | −30 °C to +100 °C |
| FKM (Viton) | aggressive chemicals, fuels | −20 °C to +200 °C |
| PTFE | universal chemicals, food | −200 °C to +260 °C |
| Metallic | steam, high temperature, petrochemical | up to +200 °C+ |
For plastic check valves (PVC-U, PP-H) the seal is material-integrated. Check media compatibility with our resistance check tool. A full overview of approvals is on the Certificates page.
With or without spring return?
A check valve without spring closes by gravity and backflow alone. It suits horizontal mounting and applications with a steady flow profile. A spring-loaded check valve closes actively through a stainless steel spring (1.4571). The spring enables operation in any mounting position — including vertical — and ensures faster closure at low differential pressure. For applications with frequent flow reversal or vertical mounting we recommend the spring-return version.
Applications — water, chemicals, HVAC and industryThe wafer check valve suits virtually every industrial pipeline. In water supply and wastewater treatment, EPDM-sealed check valves protect pumps and distribution networks. In the chemical industry, FKM or PTFE-sealed stainless steel check valves secure reactive process lines. For highly aggressive media such as hydrochloric acid or caustic soda, plastic check valves in PVC-U or PP-H provide a corrosion-free solution. In HVAC systems they prevent backflow in heating and cooling circuits. In the food industry, stainless steel check valves with a hygienic surface finish provide the necessary cleanliness. For larger sizes from DN250 we recommend dual-plate check valves for lower pressure loss.
Check valve in stock — EU-wide delivery
Fergo stocks all 377 wafer check valve variants — stainless steel, carbon steel, plastic and ductile iron — for immediate dispatch. Standard shipping via DHL reaches customers across Europe within a few working days. Each check valve ships with datasheet, 3D model download and declaration of conformity to the EU Pressure Equipment Directive. For technical questions or bespoke configurations reach our team directly.














