Stainless Steel Compression Ring Replacement for Pool Backwash Valve

[Paul Jones]

I have a 60 Sq. Ft. diatomaceous earth (DE) filter for the pool filtration system. The filter system is contained in a stainless steel canister and consists of eight fabric grids that are coated with DE. Filter grids are attached to a backwash valve that controls the flow of the water for filtering and backwashing. The backwash valve is located near the bottom of the filter and is held in place with bronze compression ring secured with six stainless steel ¼-20 hex head screws. The original backwash valve and compression ring are made from bronze. Over the years the bronze compression ring corrodes, eventually cracks and breaks, and the unit develops a slow leak. I have replaced the bronze compression ring before but this time I decided to replace the compression ring with one I made from ¼” thick T-304 stainless steel plate.

The new 0.250” thick T-304 SS compression ring is 6.8” in diameter, has a 4.65” center opening, and 0.115 step that mates with the bronze backwash valve. It was a challenge using my small horizontal band saw to cut out a 7” square of the SS plate. I couldn't cut the last inch of stainless steel plate from a 12"x12" plate and used the drill press to drill a series of connected drill holes to break it loose. I had previously ground a lathe tool for machining O-rings (see http://www.homemadetools.net/forum/l...epanning-33447 ) and used this tool to trepan the center section to avoid removing most of the stainless steel with a boring bar. The compression ring fit perfectly and I expect the new compression ring to last a long time as compared to the factory versions made from bronze.