Mains Water Installation Kit - A buyer's guide

Connecting a water fed piece of equipment such as a water dispenser, coffee machine, vending machine or combination oven usually involves adapting the connection from mains copper cold water pipe to flexible tubing or a vending hose. While this can be achieved with 1 simple fitting, doing it correctly and more importantly, legally, requires water control devices such as a non-return valve. Other devices such as pressure reducing valves (PRV) and water blocks prevent equipment or property damage in the case of pressure fluctuations or leaks.

Although the components can be purchased separately and assembled during the appliance installation, pre-assembled mains water installation kits are available in a variety of specifications to ensure a convenient, safe and professional install.

The following guide will explain what an installation kit is, the advantages of using one and the different configurations available.


What is a mains water installation kit?

A mains water installation kit is a generic term that describes a collection of close coupled water control devices. The most common devices used in installation kits include isolation valves, single or double non-return valves (also known as a check valve), pressure limiting valves, water blocks and water block reset devices.



Other common terms used to describe a mains water installation kit include install kit, installation rail and install rail.


What does a mains water installation kit do?

What an install rail does largely depends on the devices used in the rail but the main purpose is to speed up appliance installs and ensure they are fully compliant with section 6 (backflow prevention) of the Water Regulations Guide. Compliance is achieved with a non-return (check valve) and the other devices add a range of other benefits, all of which are outlined below:


  1. Water Block Reset Device
    An external reset device to allow quick and easy manual reset of a Water Block.
  2. Water Block
    A Water Block is an innovative leak prevention device which controls the maximum continuous flow of water between 5 and 50 litres. Its function is to prevent flooding and leak damage by stopping the flow of water if the quantity exceeds the set value.
  3. Pressure Reducing Value (PRV)
    A pressure reducing valve (also known as a pressure limiting valve) reduces the pressure of the liquid travelling through it. This can help protect appliances by preventing the maximum pressure rating being exceeded.
  4. Isolation Value
    An isolation valve allows the flow of water from the mains to a water service pipe to be regulated so appliances can be isolated from the rest of the mains water system.
  5. Non-return (check) Value
    A check valve is a valve that closes to prevent backward flow of liquid (backflow) and is required by law to prevent water that’s already in your equipment re-entering the mains supply. Non-return valves are available with either a single or double check. Single check valves provide Water Regulations backflow prevention compliance for fluid categories 1 and 2, while double check valves provide compliance for fluid categories 1, 2, 3 and 4.

Please note: Items 4 and 5 on the image is a single component combining an isolation valve and double check valve. It has a check valve both before and after the isolation valve.


Why use an install rail and what are the advantages?

Other than to comply with water regulations and to benefit from the advantages each install rail component provides; install rails save time and provide piece of mind.

Spending time on-site assembling various components is both inefficient and increases the possibility of leaks from bad connections. Purchasing a pre-assembled fully tested kit, which uses high quality WRAS approved components, is not only faster but usually yields better results. For a comparison, it’s a bit like spending time and effort building a kit car in your garage when a mass produced car will cost less and be more reliable – it’s generally considered to be for enthusiasts only!


Install Rail Advantages

  • Aids in water regulation compliance
  • Various component benefits such as leak prevention
  • High quality components
  • Key components carry WRAS approval
  • Fully tried and tested
  • Saves time

WRAS stands for Water Regulations Advisory Scheme. Their aim is to contribute to the protection of public health by preventing contamination of public water supplies and encouraging the efficient use of water by promoting and facilitating compliance with the Water Supply (Water Fittings) Regulations.



What install rail configurations are available?

While there are a variety of different configurations available from a number of manufacturers, we offer a comprehensive range of mains water installation kits, which include a range of different components depending on your application. The table below outlines the available kits:

MK15 MK16 MK35 MK36
Isolation (Shut Off) Valve
Double Check (Non-Return) Valve
Tamper Proof Non Adjustable PRV
Honeywell Adjustable PRV
Water Block
Water Block Reset

All install rails are available with a 1/4″ push fit outlet with some also available with a 3/8″ push fit outlet and/or 15mm copper stems. However almost any variant can be made (minimum order quantity applies) to suit your exact requirements.

View our range of mains water installation kits today and make sure your installations are both quick and hassle free and compliant with backflow prevention water regulations.