Fixing the backflow valve on my irrigation system
Springtime is here and time to fire up my irrigation system, only to discover that the backflow prevention check valve is leaking a strong stream of water. If you have hired a plumber lately, you know that they are most likely going to charge you a minimum trip charge just to stop by, most likely around $150.00. Therefore, when the backflow prevention valve for my irrigation system started leaking it was a no brainer to fix it myself.
The harsh winters here in Colorado can be brutal on things left outside to over winter. I think the gasket got brittle from the years of freeze and thaw and split, causing the leak.
Getting it apart was simpler that I thought, I was prepared for the bolts to be rusted in place. However, the valve is made of brass and I believe the bolts are stainless steel, two metals that resist rust. It came apart with easy.
Once I got it, apart I took the old gasket down to Lowe’s, expecting not to find exactly what I want but hoping to find a similar gasket or washer that I could make work. No such luck, however they did have a square piece of rubber that was 6”x6” and a 1/16th inch thick for a $1.98. I used it to make my own.
It was a simple process, I used the valve cover as a template and traced around it with an Exacto knife to cut out the shape.
I then found a drill bit that fit perfectly in the bolt holes in the valve cover, to drill through the rubber. To drill clean holes and keep the rubber from tearing I used a brad point bit because the shoulders of those bits have a square edge and will cut a cleaner hole over a twist bit. When drilling the holes in the rubber I placed it on a sacrificial piece of wood I could drill into, placed the valve cover over the top, and drilled through the bolt holes. There was one other hole I needed to drill, I`m not sure of the purpose for this hole. A plastic tube ran through this hole transferring water to the back of the washer. To cut this hole I was able to feel the location through the rubber and pushed the drill bit through the rubber, twisting it by hand.
All in all the whole project took one trip to the hardware store, about 20 minutes of fabrication time and cost $2.00 in materials to complete. That sure beats waiting around for a half a day for a plumber to bill me 150 bucks to replace a rubber washer.
Just in case you wanted to know, what the inside looked like. Behind the white plastic, this is a spring, which I believe helps control the pressure. There is another valve cover on the top. I would take extreme care if you needed to remove that cover. In the metal, it is stamped. “Spring Loaded” so if you take that cover off the spring may fly out. I did not remove it to find out; if you are leaking from that cover, it may be safer to call a plumber.
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