Flange for HW cylinder outlet with 22mm compression fitting

16 Jul 2011
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United Kingdom
I am fitting a stainless steel replacement indirect open vented HW cylinder, the outlet on the top of the cylinder is a 22mm compression fitting (as are all the other inlets and outlets). I want to fit a "shower flange", however I can only find flanges that fit to a 3/4 or 1 inch outlet.

Does anyone know of a shower flange that will fit directly onto the 22mm compression outlet?

If not what do I use to fit a flange, bearing in mind that if the flange is lifted up too much it won't be reaching far enough down into the cylinder to avoid any air bubbles.
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Is it possible that there's no 'stop' in the 22mm compression fitting and 22mm copper will go into the cylinder?

You could think about using a 22mm Essex Flange.
Can you not remove the 22mm comp fitting leaving a 3/4 inch bsp female thread? or is that not the way the SS cylinder is constructed?
Only cylinders i've come acroos that are SS would be unvented units , if SS vented then surely it would be supplied with a 1" or 3/4" BSP female thread. :confused:
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The tank is a Gledhill Stainless Lite, it's the same cylinder as the unvented except there is a stop end in the tank where the temperature and pressure relief valve tapping is. Their literature says 22mm compression fittings.

Having posted I then noticed an identical thread I had missed before suggesting that the male 22mm male compression fitting thread (It's got an olive and a nut so I know its a compression fitting) was probably the same as a 1 inch BSP thread. Putting my calipers on a 22mm compression fitting the internal female thread you tighten onto the olive measures fractionally over an inch maybe 25.9mm. The external diameter of the pipe being 22mm.

Obviously I don't want to strip the thread on the outlet of an expensive cylinder but maybe a surrey flange with a 1 inch BSP female thread will fit.

I will speak to Gledhill on Monday to see what they say (especially before I risk damaging the thread). The plumbers merchants state that the tank has a shower take off, in fact this is a secondary return which is 350mm from the top of the tank, I didn't buy a 210 litre tank to leave a quarter of it unusable by the showers. I want to draw the water for the showers from the top of the tank.
these duplex cylinders can be adapted to suit any installation,usually adapted by the maker or off the shelf from others.
warranty issues will stop me from telling you anymore.
there is also a level of comptence required,so leave it to a registered professional.
i think the benchmark scheme includes cylinders.
anyway good luck.

15mm compression nut threads are BSP. All other sizes are ba*tard threads, generally manufacturer-specific. DO NOT try to put a 1" female BSP fitting onto it. You will kcuf it up beyond repair.

If the 22mm connection is integral to the cylinder, i.e. not removable to leave you with a BSP thread, your options are limited.

I could suggest a botch that would involve 15mm being your dip-tube, but lets see if the pros can come up with anything first.
If you insist on not using the secondary return connection then perhaps you would prefer to insert a downward facing 22mm tee into the horizontal 22mm pipework as near to the cylinder as possible. This way you avoid the air/CO2 bubbles.

I still prefer the side of tank tapping (Essex), it holds back some hot water for the taps after the teenagers have showered until it goes cold!
I'm taking the easy way out and returning the cylinder for a copper one with shower take off (with dip tube) pre-installed. It's £50 cheaper and doesn't require either my bodging or mackling skills.

Thanks for your comments.

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