Hot Water Cylinder 22/28mm Compression Fittings

[Marty1966]

Can anyone assist please - The new cylinder has 22mm connectors for the top and coil flow and return. The current pipework is 28mm. Ideally I require a Compression Adapting Female connector that will screw into the tank on 22mm and adapt to 28mm to take the pipework.
I cant seem to find this - unless its referred to a 22 x 1" ??
Many thanks

 

[Deleted member 267285]

Are you sure they’re 22mm? Are they bsp or compression?

 

[lostinthelight]

,

 

[JohnD]

As The Novice says, it may be a screw-in tapered BSP thread. post some photos to be sure. They are a fitting that benefits from PTFE tape on the threads.

BSP threads are named in fractions of an inch that are surprisingly not the same as they measure, because the name is based on the internal diameter of an old iron pipe with the thread on the outside.

 

[muggles]

What kind of system do you have? Is it fully pumped? If it's gravity hot water then it sounds like you have the wrong cylinder, and it won't work on your system (IE it won't get hot)

 

[Marty1966]

Thank you all. Its a vented indirect system primary pumped - identical spec to whats been replaced.
JohnD - its confusing but your explanation makes sense of the confusion. Ive removed the nuts off a 22mm compression joint and it screws on perfectly so I can only assume 22mm is right.

 

[denso13]

identical spec to whats been replaced

If that's the case then use the old coil connectors.

 

[Marty1966]

If I could I would - they are practically welded on and won’t budge. Got around it in the end thankfully all up and running