What's this bit for?

It's a spare inlet cone (inside the main blue body). The valves usually come with two one white (inside) and one red, one is for high pressure water and the other for low pressure but I can never remember which is which!!

HTH

John

Devany coughed up some electrons that declared:

Sure it's not a spare nozzel - high pressure vs low pressure?

Its an alternative/spare nozzle. Either the ball valve has a low pressure nozzle fitted & the red one is a high pressure, or t'other way around, can't remember which. It goes behind the black rubber diaphragm. Its so you can swap them over for differing water pressures - you don't need both.

The old-type ball c*ck had a much bigger hole for low-pressure feed. I don't know about the modern things.

The red is the low pressure nozzel. The fitted white nozzel is for mains water pressure. If your cistern is fed from the tank in the loft then replace the white one with this.

they usually ship with the high pressure one fitted.. its better to have too little flow than too much when someone doesn't swap the nozzle.

The one with the little hole is for high pressure.

It's pushing harder, so it doesn't need such a big hole, if that'll help you remember.

Andy

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Devany saying something like:

That's a spare dooda, you'd better not lose that.

Actually, it's an alternative insert for low pressure feed. The red one has a bigger 'ole than the white one which is already inside.

Aha! a spare nozzle.

Brilliant, thanks for all the replies.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Andy Champ saying something like:

Ooh, you are awful.

BTW: Note to OP. Don't lose that spare nozzle. It may save you, or somebody, the purchasing of a whole new whatsit at 2.00 AM some dark night during a long Bank Holiday weekend in year 2017! Or does stuff last that long these days? Good luck

The plastic bits probably will... I've just had to replace a drop-valve release mechanism because the short length of Bowden-type cable to the activation buttons had corroded through and I couldn't find a suitable replacement for that. Fortunately, I found an identical fitting so it was a simple clip-on job, greasing the cable first to prevent it happening as quickly again.

Why did I use this modern solution to replace a 30-odd year old syphon valve???