Thread size / adapter

[ruralboy]

Hi, I opened the box on a esbe mixer valve for our radiator system and it has completely the wrong fittings from what I ordered (threaded flat flange 3/4), instead it has 22mm compression olive fittings, plus it has a dent on the olive area so it wont seal. It has the flow specs when I checked on the esbe site, but its sat round in a box since last winter and now too late to send it back, and too late to order another (it took our supplier 7 weeks to get this one!).

I can however machine the end true to below the damaged olive taper depth (on a milling machine) giving a flat flange fitting as originally ordered but the thread on the nut is not 3/4" bsp. The threads are much finer and its a slightly different size. I'd like to do this to end up with a screw fitting rather than trying to recreate the olive taper deeper in, as things might get a bit tight if I take that route...

Anyone know what it is? Its not a unique size I found the same thread on a orphaned tap body fitting in a box. I can measure the tpi but this is usually something people out there know off the tops of their heads. I can make it flat and get a fitting next-day'd here from someone else if I know what to order.

TIA

 

[TicklyT]

Brass fittings traditionally used BSB (British Standard Brass) threads.

BSB threads are 26 TPI, 55° Whitworth thread form for all diameters.

The metric equivalent would be a 1mm pitch 60° ISO thread form.

However the fitting manufacturer is free to use whatever thread form and pitch he considers appropriate - he is supplying both threaded components, and the only 'standard' he has to meet is the need for the fitting to accept a 22mm olive.

I would be more inclined to make up a tapered reamer to clean up the damaged seating.

 

[ruralboy]

Hi, thanks for your reply, I took the advice and mounted it on the lathe faceplate with a heath robinson setup, and turned a new olive seating on it. I was thinking about soldering the pipe into the fitting solid, but figured the heat would damage the rubber seats inside.
Might order a new one anyway just as a spare in case it starts to weep after being damaged in transit, but for now its good enough.