Water supply blockage any ideas?

[Gone West]

The water supply slowly stopped working over about a two minute period. I isolated the problem to the water softener and found there was no water entering the softener although there was plenty of pressure. I disconnected the pipe feeding the softener and found a small plastic cup 15mm diameter completely blocking the end of the flexible hose to the softener. Upstream of where the plastic cup lodged is the softener ball valve, pressure reducing valve, stop cock and double check valve. Could the plastic cup have come from the pressure reducing valve or even from somewhere in the supply pipework outside the property? The pipework etc has been connected and in use for at least two and a half years without being altered. I would like to have an idea before I connect everything up again because I’m very puzzled.

 

[SuperJohnG]

Very strange. 

 

As a guess it is most likely form the ball valve.. possibly the half of the 'ball' part that creates the seal in the ball valve. My guess is it has split in two  and come away. I would have normally thought it was metal though.  

[Gone West]

44 minutes ago, SuperJohnG said:

Very strange. 

 

As a guess it is most likely form the ball valve.. possibly the half of the 'ball' part that creates the seal in the ball valve. My guess is it has split in two  and come away. I would have normally thought it was metal though.  

I don't think so. IIRC the s/s ball sits in a nylon type seal and it's a 22mm full bore valve so larger than 15mm. Everything still works okay, the ball valves and pressure reducing valve. I'm at a loss to explain it.

[Gone West]

@Nickfromwales @PeterW or any other plumbers. Any ideas before I connect it up again, please.

[Nickfromwales]

Looks like one of the shields around the moving part of the ball valve to me. Can you strip that out and rule it out?

[Gone West]

5 minutes ago, Nickfromwales said:

Looks like one of the shields around the moving part of the ball valve to me. Can you strip that out and rule it out?

Do you mean the seal that the ball sits in. It's a 3/4" full bore so wouldn't the seal be more than 15mm diameter.

 

https://www.bes.co.uk/ball-valve-3-4-bsp-p-f-x-f-red-butterfly-handle-11768#product-details-tab

 

 

[Nickfromwales]

Not sure TBH as I've never disassembled one, just cannot think of what else that could be..... Possibly a stray blanking plug installed by a manufacturer of one or other bits of kit upstream?

My best guesses I'm afraid! 

[PeterW]

Is there a non-return valve anywhere in the system ..??? And my guess is the blue butterfly valve swivel ball.. 

[Gone West]

1 minute ago, PeterW said:

Is there a non-return valve anywhere in the system ..??? And my guess is the blue butterfly valve swivel ball.. 

There's a 28mm double non-return valve before the stop cock. The butterfly valve ball is closed and not leaking.

[PeterW]

Could be the ball off the DCV but never seen one do that tbh ..! 

[Gone West]

Just now, PeterW said:

Could be the ball off the DCV but never seen one do that tbh ..! 

I guess that means it's no longer working if it's that.

[Gone West]

@PeterW Sorry for being slow, I see what you mean now. So half of one of the spheres on the DCV has somehow passed through the PRedV. Hopefully the other sphere is still working to prevent backflow and the other half of the broken sphere is still attached inside the valve.

[PeterW]

Yeh they are a spring and a piston - looks like the cap of the piston 

[Gone West]

Thanks all for your help. It's all back together again and working as normal. It's an RWC Floguard DCV so not cheap but from the picture looks like what @PeterW suggested. I am going to try to find a dimensioned sectional drawing of it to check the diameter of the plastic cup.