Single Check Valve Brass 22Mm

Single Check Valve Brass 22Mm

The 22mm Brass Single Check Valve (also known as a Non-Return Valve) is a critical safety and functional component in plumbing and heating systems. Its primary purpose is to permit water to flow in one direction only, automatically preventing "backflow" or "back-siphonage" which could contaminate the mains water supply or disrupt the operation of a heating circuit.

This valve is a Fluid Category 2 protection device, suitable for preventing the backflow of water that has undergone a change in temperature or has had substances added to it that do not represent a significant health hazard.

Key Features and Specifications

Size: 22mm Compression ends (Standard UK size for main cold water feeds and heating flow pipes).

Material: High-grade DZR (Dezincification Resistant) Brass body for long-term durability.

Internal Mechanism: Spring-loaded plate or "poppet" that opens under pressure and snaps shut if the flow reverses.

Pressure Rating: Typically rated up to 16 bar.

Temperature Rating: Suitable for temperatures up to 85°C or 90°C (brand dependent).

Standards: Manufactured to comply with BS EN 13959 and WRAS (Water Regulations Advisory Scheme) approval for use with potable water.

Common Applications

Outside Taps: Installed on the internal pipework leading to a garden tap to prevent contaminated hose water from siphoning back into the house.

Combi Boiler Filling Loops: Often integrated into or placed next to the filling loop to prevent central heating water from entering the mains.

Showers and Mixers: Preventing cross-flow between the hot and cold water supplies in thermostatic mixing valves.

Pump Protection: Installed after a pump to prevent the weight of the water column from spinning the pump backward when it is switched off.

Unvented Cylinders: A crucial part of the cold water combination valve assembly for unvented hot water systems.

Installation Guidelines

Flow Direction: Look for the embossed arrow on the valve body. The valve must be installed with the arrow pointing in the direction of the required water flow.

Positioning: Because it is spring-loaded, this valve can be installed in any orientation (horizontal, vertical, or at an angle).

Accessibility: Check valves contain moving parts that can eventually scale up or fail; they should be installed in an accessible location for future testing or replacement.

Plastic Pipe: If using 22mm plastic pipe (e.g., PEX or Hep2O), ensure you use the correct 22mm pipe inserts before tightening the compression nuts.

Essential Companion Products

Isolation: 22mm Full Bore Lever Ball Valve (Install before the check valve for easy maintenance).

Inserts: 22mm Plastic Pipe Inserts.

Sealing: Silicone Grease (for the compression olives if required).

Tooling: Two adjustable spanners to ensure a secure, counter-tightened joint.

Specialist Support and Local Collection

Correct backflow prevention is a legal requirement under the Water Supply (Water Fittings) Regulations. We stock 15mm, 22mm, and 28mm check valves in single and double configurations.

Visit our trade counter at 61 Fullers Road, E18 2QB for immediate collection. Our team can help you determine if your specific application requires a Single Check Valve or a Double Check Valve for higher-risk Fluid Category 3 protection.