Replacement backflow valve piston

[WobblyHand]

Float valve is complete. Finished just before lunch. Fits great in the assembly.

So this part of the project is over. Next I will drill and tap the valve bonnet cover for 8-32 screws. One of the 6-32 holes is stripped and it seems not to have been drilled correctly. So I will drill with a #29 drill and tap to 8-32. Think I will put in some stainless screws to hold the lid on.

The copper unions have been giving me trouble, they are very hard to get leak free. 4 out of 5 times they don't seal right at all. Think I will replace them. I found this style at McMaster, which look ok. They are $11.19 each in the 1" size.

McMaster-Carr

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[WobblyHand]

Drilled and tapped the bonnet for 8-32 screws, the next size up. Waiting for the unions and some stainless hex head screws to arrive. They should arrive tomorrow. Took a picture of all three float pistons, to see the difference. Glad I learned on the aluminum one, as that was my second try.

Pity I have to install the brass one, it came out pretty well. At least I have the picture of the three little pigs!

 

[WobblyHand]

Got the screws and installed the float piston. The unions that I bought were a bust. They were not even close to the picture in the product description. Haven't seen a substitution by McMaster this way before. Sent them pictures, and they said to for me to keep them and they would refund my money. Guess I can install them as a last resort if I can't get the original unions to seal.

Will install the whole assembly tomorrow. Hope not to get too wet!

 

[WobblyHand]

Well, got waylaid yesterday.

Anyways, got the whole backflow valve installed today. Used teflon tape on the old fitting threads which made it easier to tighten. Sort of a single use lube. Also picked up a HF special big 18" crescent wrench. $14.95, so not too terrible. Used a pipe wrench on the nut and the crescent wrench on the pipe. With two 18" wrenches it was easy to make it tight. Turned on the water, and thought I had a leak. Nope, it was the washing machine. No leaks at the house union. Turned on the main valve and water came out (as it should) and then the float sealed and cut off the water to the bonnet. Then turned the valve to the irrigation system. No leaks either! Dried everything off and watched for a while. No drips.

Success! Project complete.

First pic: Completed assembly with water on. Second pic. The new 8-32 screws that I drilled and tapped into the bonnet, to hold on the lid. The lid diverts the water to the ground, rather than having the water go up the side of the house! I know this from personal experience