Automatic Sprinkler System Maintenance.
I will cover a few of the main problems that people come across with the in ground part of sprinkler systems.
1. Water Leaking from Sprinkler
The main one is when people find water leaking from a sprinkler they think there is an issue with the sprinkler. This is not normally the case unless a sprinkler has been damaged by a mower or edger. The normal cause of the leak is either a worn or damaged diaphram in the valve or some grit which has become lodged in the diaphram where it seats in the valve.
A worn diaphram must be replaced but if there is grit embedded in it then the grit can be carefully prized out and the dint left there will grow back in a few days which will overcome the leak. Diaphrams in good quality valves these days will last 10 to 15 years in clean water without any problems.
2. Drippers leaking in Gardens
Sometimes you will come across a similar problem with drippers in a garden. An area will always be wet. If this is at a low point the first place to look is at the valve as above. Another thing that happens with drippers in a garden situation is someone will put a shovel or fork through the pipe. All prongs of the fork will hit the pipe, not just one. That is just how it happens.
3. Adjust Dripper Valves
At times with drippers, if there is too much pressure, a dripper will blow out or blow apart. Not a big deal to fix but when they are on for an hour there will be a big puddle. Many solenoid valves are adjustable so you ca turn them down. Rule of thumb with drippers. Turn the valve on and allow the line to build pressure then pull apart or remove a dripper so you can see it from the valve. Turn the flow control down until the water flows gently and not a pressure squirt too about 2 metres (6 feet).
4. Check and Replacing your Valve Diaphram.
There are a few ways to open up a valve depending on your type of solenoid valve. Always turn the master valve off or house water main.
Some valves have a cap about 75mm diameter that is just screwed off. Normally hard to do though without the correct tool. ALWAYS be really careful with the coil on the top of the valve. If you are a little bit rough they can break and quite often cost more than a new valve. Most others have screws to retain the top of the valve. If you remove the coil first and this makes life easier, be careful not to loose the parts. Inside the coil when you remove it is a small metal plunger about 20mm x 4mm with a 20mm spring behind it. Some are encapsulated but most are not and if you drop the little spring in a valve box full of muddy water you will never find it. When re-installing plunger put the rubber end outwards.
Before taking the top off the valve, dig a ring around the valve so it goes 20mm below the top. Be careful with the wires on the coils as they can be damaged too. Remove the top and check for grit in the seat and tears in the rubber. If you need a new diaphram you will need to get the model and brand off the valve. If you can’t find one don’t stress as most are different. Either get your phone and take a photo of it or draw a sketch and describe shapes of parts and go to your Landscaping or Irrigation shop. Clean it and re-assemble.
Bruce Moller. Lifestyle Landscaping Solutions, Bundaberg Service Manager