Weird compression fitting

[williamglossop]

I need to reduce 35 mm mdpe down to 28mm. I've seen these fittings but no idea how they work....... there doesn't appear to be any threads, so I assume they are not typical compression fittings. Anyone know how to use them? I can't fit one of the ridiculous Speedit reducers cos they're the size of a fist.

https://www.bes.co.uk/35-mm-x-28-mm-reducing-set-17741/

 

[RandomGrinch]

Hi,

I'm only a DIY'er, so I may be very wrong!
However, I believe those fittings are internal reducers for brass compression fittings.
For instance, if you had a 35mm compression tank connector, like:

Those parts would then replace the 35mm olive, to allow the 28mm pipe to be clamped inside.
But again, I may be wrong!

 

[oldbutnotdead]

I've used similar dropping from 22mm to 15mm. You need a 35mm Something brass compression fitting (tap, straight coupler, elbow, whatever) as well- the reducer allows you to seal your smaller tube into the larger connector.

 

[magicmushroom666]

I'd agree with Grinch, plus a brass olive isn't going to seal against MDPE, The MDPE fittings I've used all have rubber 'O' ring seals, with separate teeth to secure the pipe.

 

[Madrab]

That's called an internal reducing set that's used with a 35mm compression straight coupler. Are you going to 28mm copper or is it actually 25mm MDPE?

To use the reducing set - With a hard insert in the 35mm MDPE, that fits into one end of the straight coupler and is tightened. You then have a hard insert in the 25mm MDPE, that then fits into the other end of the coupler that has the reducing set in it and then you tighten that side up. You can use hard olives with MDPE pipe you just need to ensure it has an insert. If it's 28mm copper then obviously no insert needed.

Alternatively you use a 35mm MDPE to 28mm copper reducing adapter.

edited for typo

 

[fezster]

I've not heard of 35mm mdpe before. You sure it isn't 32mm?

If so, and you're going to 28mm copper, I'd recommend a plasson pushfit reducer (mdpe with insert on one side, and copper in the other).

 

[Madrab]

That's why I asked about the 28mm, never even thought about the 35mm ... DOH ... I need to wake up methinks