Shower pump feed off 15mm secondary return?

[gmartine]

The open vent cylinder is stainless with the neck too small to fit a surrey flange and I'm just plain reluctant to try and fit an essex flange in stainless. I could just tee off the HW outlet but is there a flange out there with a narrow (less than 15mm) dip tube or I'm thinking I could make use of this cylinders secondary HW return to feed the pump. Is it possible...what do you think?

 

[ShaunCorbs]

Yes as there designated either secondary return or shower pump

Gledhill cylinder?

 

[gmartine]

Great thanks, just realised secondary return outlet is 22mm but someone used a lockshield to cap it off, all good then.

Don't recognize the cylinder and there's no data/installation sheet. It's about 450 x 1100, blue foam, indirect, one and only immersion is at cylinder base + secondary return in a modest house with a conventional s plan.