DE Filter Problem

[rschrei518]

I have a hayward de4800 and my issue is with the pressure relief valve the threads on top of the tank are damaged when i try and thread the relief valve in it just spins. I have a blank cap with no gauge or relief which threads in fine it just seems that the threads on the blank cap are thicker and longer. The threads on the relief valve are badly designed not because i have this issue and every 2 years the threads just break off the relief valve so i always have to replace it. Any tips on how i can maybe build something which may work or repair my existing threads?

Here is a diagram of the relief and tank

http://www.poolcenter.com/parts_filter_ ... _clear.htm

 

[spishex]

Re: DE FILTER PROBLEM

Welcome!

If the threads on the current air relief are crossed then that's that. Use the cap until the new one arrives.

On the next one you might try using teflon tape instead of depending on the o-ring. That will allow you to thread it in just a bit further and there'll be no o-ring to disintegrate, which may be why you end up having to tighten it every 2 years or so.

 

[rschrei518]

Re: DE FILTER PROBLEM

I have a brand new relief valve and tried it and it is no better its the threads on the tank itself that is worn any ideas on what i can do?

 

[spishex]

Re: DE FILTER PROBLEM

Ah, I get you. Perhaps you could buy a smaller air relief valve, one with 1/2" threads let's say, and then tap corresponding 1/2" threads into the blank cap?

 

[rschrei518]

Called Hayward and they are NO help they pretty much say try teflon tape or buy a new tank. Teflon tape is not helping. Today i went shopping to find fittings or anything the size of the blank cap but nobody carries plastic fittings in my size. I did find a relief valve made by pentair for a pentair tank and it has larger threads my question can i or should i try enlarging the existing hole and rethreading it and if so how would i go about rethreading the existing hole at the top of tank?

 

[Durk]

Try a brass nipple threaded into the tank, and then a coupling (brass or PVC) to attach the male thread on the relief valve to the nipple. The nipple should go deep enough into the tank to reach the good threads that are left at the bottom of the hole. Use Teflon tape and don't bother with the O-ring. Some people get nervous about metals in pool systems, but one nipple (that actually has no flow through it) will not do anything you have to worry about. My 1946 pool had 2-inch brass gate valves and a bronze pump. When we got our first multi-port valve in the 1960's, it was made of brass. Heaters are mainly metal.

Drilling out and tapping a thread into the hole in the tank to take a bushing is another approach, but I wonder if there is enough material around the top hole to support a larger hole. I'd try the nipple first. If it doesn't work, then drill and tap is about your only choice.