Top-up bottle valve?

[ian29gte]

I have a sealed system, with a plastic top-up bottle. The bottle is connected to the system via plastic tube, and a valve. When the system is pressurised, the valve to the bottle shuts. Should the pressure drop in the system, the valve opens to allow the water in the top-up bottle to drain into the system, keeping it topped up.

The valve was playing up yesterday, so I stripped it and found some thread tape stuck underneath it. It's working fine now, but I have been unable to locate any valve of this type, in case I'm not so lucky in the future.

The valve is brass, has a threaded port for a auto air vent. It has KIWA and Ocean stamped into it. Two local plumbers merchants said they'd never seen anything like it before, and an Internet search has so far proved fruitless.

Any suggestions?

 

[galaxy_plumbing]

sound interesting, could you post some pictures?

 

[ian29gte]

I would if I knew how. The usual method of posting Photobucket links doesn't work here.

 

[ian29gte]

Thanks to Petercj, I've managed to do it!

Please see. First picture is top-up bottle end, third is from pressure system end, and last is how it's fitted.

 

[ian29gte]

So, nobody recognises it?

 

[stevetheplumber]

havent seen one of those for over 20 years it was the first attempts to fill sealed systems automaticly i cant recall where they came from you will probably have to change it to a filling loop or repipe it using a non return valve

 

[ian29gte]

The system was put in in about 1988, so I guess you're right. There's already a mains filling loop, but if the pressure falls due to a leak to below that in the bottle, it automatically drains into the system. And as the boiler has no water pressure cut-out switch, only an over-temperature switch, it's a pretty good function. I reckon the bottle holds about 3 - 4 litres.

Still, if no one knows where I can find a new one, so I expect I shall simply have to put a manual valve in there instead. Shame.

 

[dancinplumba]

does your system have a pressure relief valve by any chance ?

 

[ian29gte]

Yes, on the outlet side of the boiler, gauge included.

 

[Mikefas]

Interesting Ian, I dont suppose you would have a picture of the top up bottle in service would you, I could do with that, thanks, Mike

 

[ian29gte]

Interesting Ian, I dont suppose you would have a picture of the top up bottle in service would you, I could do with that, thanks, Mike

If you look at the last picture, the plastic tube goes up into the bottom of the plastic bottle. The top of the bottle is not sealed, just a screw top. It's just a plastic bottle!

 

[Mikefas]

Saw that Ian thanks and Ive seen one operation in an art gallery in south london years ago but just needed a pic with bottle and tubing connecting to system for a presentation, thanks anyway guv.

 

[ian29gte]

If I get time tonight, I'll post one for you.

 

[chris watkins]

To answer your original question ian, if the single check valve inside that tee ever gives out it will not require a direct replacement fitting, it will be easy enough to replace it with a new 15mm single spring loaded check valve & a 15mm equal tee & reconnect the plastic hose & the A.A.V.
If you are not sure of the fittings required one of us on here would be able to point you in the right direction from your posted pictures.

BTW thanks for posting the pic's & I would also be grateful if we could also have the bottle, as well (if poss one that shows then all together)

 

[Mikefas]

Thanks lads

 

[ian29gte]

 

[Mikefas]

Ian thats perfect, youre a star thanks a million

 

[Centralheatking]

Water does not compress so it wont work on a sealed pressurised system -

This bottle is very like the early SERVOWARM systems in the late 60's & 70' which was a sealed system in that there was no direct connection with mains water at all. We used a milk bottle to top it up. The boiler was a 'master radiator', a Radiator look alike but with a burner set inside feeding central heating water to 6 rads or so around the house.

oH DEAR ! THAT INFO IS ALMOST 50 YEARS OLD

centralheatking

 

[stevetheplumber]

Water does not compress so it wont work on a sealed pressurised system -

This bottle is very like the early SERVOWARM systems in the late 60's & 70' which was a sealed system in that there was no direct connection with mains water at all. We used a milk bottle to top it up. The boiler was a 'master radiator', a Radiator look alike but with a burner set inside feeding central heating water to 6 rads or so around the house.

oH DEAR ! THAT INFO IS ALMOST 50 YEARS OLD

centralheatking

your wrong we used to fit these on sealed systems in the 80's and they do work but what usually happens is no one fills the bottle

 

[ian29gte]

The system actually works very well indeed. It copes with minor leaks from rad valves etc. The bottle will top up the sealed system when the pressure drops, thus ensuring that the boiler doesn't trip out on overheat due to lack of water. Until of course the leak becomes so big, that it empties the bottle. It's kind of a back-up, really. Of course, the bottle must be checked on ocassion, but seeing as it's right next to the boiler which has the system pressure gauge on it, it's no hardship, and I look in the boiler room about once a week.

The one thing I am curious about, and have yet to determine (because my wife has banned me from pulling it apart during the winter months), is whether the valve uses a differential piston. I won't know that until I strip it down in springtime. It is leaking past from system to bottle, but ever so slightly, and I can't afford to be without heating!

 

[chris watkins]

The space in between the AAV con & the hose con would suggest it is just a small single check valve mechanism i.e. light spring holding a valve seating closed, possible O-ring seal, which is pushed tightly closed as system water is heated & water expands.

 

[ian29gte]

Yes, it has an O-ring, but I don't remember if it had a spring in it when I took it apart to clean it out. Hence the differential piston comment. And I won't know for a couple of months or so.