Cut-in's & Back flow prevention - what's it all about and why is it so important?
The Cut-in
If your reticulation system is running from the mains water supply - you will have a cut-in from the main feed to your property, which will be connected to your reticulation main feed pipe. This connection has to be carried out by a Licensed plumber, and is classified as major plumbing works.
The cut-in is normally done in copper pipe, and involves the plumber installing a tee connection in your mains water supply feed, and branching off to an isolation valve, so your reticulation system can be isolated in the event of a maintenance issue.
Regulations were put in place many years ago, to ensure that this cut-in was performed to a certain standard, and that it be done using kitemarked tested products.
New legislation saw to it that all cut-ins were professionally installed using a kite-marked isolation valve, or a ball valve as they are known, and directly connected to this via a 'screw fitting' must be a dual check non-return (backflow prevention) valve.
The purpose of this legislation primarily to protect the quality of our drinking water supply. Without a backflow prevention valve in place, syphonage could occur at the mains feed, and dirty and contaminated water could potentially be sucked back in to the main water feed, and contaminate the water supply further down the line.
Master Control Valve
The next connection after the compliant cut in, is your reticulation system, and this should start with whats known as the Master Control Valve. This is a solenoid valve controlled by your reticulation controller, and its main purpose is to isolate the mains pressure from your reticulation pipework when the system is no in use. The master control valve is programmed to open with each of your station solenoids as the system runs, and to close when the cycle is complete. This will ensure that your reticulation system cannot keep running in the event of one of your station solenoids sticking open. The master control valve should be connected by a screw fitting to ensure no glued joints are left under mains pressure.
Is my system compliant?
Most modern homes built in the last 10 years will more than likely have been fitted with a compliant cut-in kit. However many older homes are not fitted with them. There is no need to immediately install the compliant cut-in, however if there is any requirement to modify the cut in, or to perform maintenance on your master control valve, you must install the compliant cut-in isolation valve and dual check non return valve to bring the system up to code.
We visit may properties throughout the year where the retic system doesn't actually have a master control valve. This is usually highlighted when the customer reports one of their stations running despite the controller being turned off. Frequently the station will run continuously until the water is switched off at the mains. In cases like these a compliant cut in must be carried out, and the relevant isolation valve and dual and check non-return valve be installed.
A professionally installed compliant cut-in is the first step in any new reticulation installation, and is an important upgrade to older reticulation systems installed in Perth, Western Australia.
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