Ball valve seating washer disintegrates after 6 months

Hello,i was hoping someone could help me. About 12 months ago neighbours let us know that the overflow pipe for our mains water fed loft cold water tank was at the back of our property was constantly leaking and causing damage to the rendering of the wall.(we dont use this area. Car park for other buildings)

I know nothing about plumbing but bought a new ball valve and replaced seating washer with a new washer (cant remember if it was an actual seating washer or just similar in size+shape)

About 5 months ago i had to completely uninstall thecold water tank in order to insulate space behind it. I noticed that the seating washer was more or less ruined so replaced it with a general washer that looked identical.

Due to a lot of work needing done in loft i am just about to finish insulating now which means access to loft cold water tank would be a nightmare once new insulation is down. Would ruin all my work. Checked that seating valve and same story,looks ruined already.

Ive bought a proper "dedicated" seating washer but looks same as others i used. Is the problem the water pressure is too high. Should i turn pressure down a tad by adjusting the stopcock outside?

Antone any ideas? Ive used similar ball valve as originally installed. High pressure ball valve were water escapes from bottom rather than side. Its a smallish tank.

Any help at all would be appreciated. Wanna get insulation finished and fan ducting hooked back up. Dont wanna have to undo it all again in 6 months because seating washer is buggered again and neighbours complaing of the constant leak from overflow pipe.

Thanks for your time and effort. I can upload detailed images if need be when i get home from work in 3 hours.

Thank you for your help.
Ted

Think there are different versions for high and low pressure.

Its an area that may need maintenance though so I would want to arrange the insulation accordingly.

Assume you have lagged the pipes with clip on foam.

Picture might help. I'm new here and understnd we have to link to pics hosted elsewhere until we are trusted.

Roy

Give us some pics mate I think we may be getting terminology mixed

Sorry guys, im not that familiar with plumbing lingo im probs getting mixed up. Im going into loft in an hour and will be taking more pics.

These are just pics from the internet.

Use the rubber type washers instead of the red fibre washers.
The hard and brittle new fibre washers are intended to soak water and become soft and swell a little once fitted, but if they seem to be badly deteriorated, just use rubber type.

Also get the pressure tested and if too high have a pressure reducing valve fitted to the mains to the house

Best said:

Use the rubber type washers instead of the red fibre washers.
The hard and brittle new fibre washers are intended to soak water and become soft and swell a little once fitted, but if they seem to be badly deteriorated, just use rubber type.

Also get the pressure tested and if too high have a pressure reducing valve fitted to the mains to the house

Click to expand...

"Just use rubber washer". Ffs, such a simple solution yet a solution I could never have came up with by myself. Thanks for that best.

I had bought plumbers assorted washer pack and right enough theres an identical rubber washer. Think that should do the trick actually.Feel stupid now.

Thanks again best,much appreciated.