metric thread on rad-valve union-nut. Unusual?

[foy]

Hi guys.

I removed a radiator, for plastering wall behind it, and have found that the (compression?) nut on the tail which tightens onto the valve isn't BSP.

I found that a 3/4 BSP cap fits onto the valve fine but you can't thread the union nut onto a 3/4 BSP plug.

The nut is almost identical in size to the BSP cap but has a finer thread.

I checked further with a metric thread file and M10 x 1.5 tap and it is bang on 1.50 pitch so definitely metric. Also checked with imperial thread gauge and & neither 14TPI or 16TPI fit.

It's no major problem as I can re-use the original parts but I'm just curious as to why the maker (Concept) would have used an oddball thread like this when everyone else uses BSP afaik.

NB. I've got several pics to post up but can't seem to do so as getting error message saying 'too many URLs' even if I only add one picture

 

[turnpin]

Hi foy is your plug hollow type or solid type......you could unscrew tail out of Rad couple up with valve and then cap off with standard bsp cap......regards Turnpin:8:

 

[foy]

Hi turnpin. Yes I was thinking that. It is hollow (like a ring) and I've removed the tails so could, as you say, put a BSP nut on now but the valves are still attached to pipes and they have the metric thread.

I'm just curious rally.

Wish I could post some pics up but I think cos am a new user it's restricting me

 

[turnpin]

Hi foy you are correct about loading up pic's perhaps one of the mod's will see this and get you to send the pic's to them by private mail and might upload them here.....if only I was a bit more tech savvy I'd do it for you .....pic's would be helpful ...regards Turnpin:computer:

 

[REDSAW]

looks like a peglar valve, best change the lot!

 

[stevetheplumber]

ive had fine threads on rad tails usually early italian stuff ,reuse the old rad tail often they had a washer and rubber in the pipe work side rathger than an olive and the pipe was shorter entry