Theoben Rapid 7 Mk1 Buddy Bottle Thread Blanking Plug

[ColinH]

Hello all, I have a slight leak from the ball bearing in my Rapid 7 Mk1 buddy bottle.

Does anyone know what the thread size is, and where I can buy a "blanking plug" so that I can seal it after I get it recharged?

Thanks C/

[Ca_Varminter]

Theoben made Hex aluminum Caps to seal them....
1/4"Bspp


Stuart

[ColinH]

Thanks, but what is bspp?
I've heard of bsp British Standard Pipe which is tapered I believe?

But not bspp?

C/

[Ca_Varminter]

Bspp...
British Standard Pipe PARALLEL
The Thread is not tapered!
That is why it uses an O-ring or Dowdy sealing washer in the setup to seal!

Stuart

[ColinH]

OK thanks for clarification Stuart.

I can understand how the BSPP (parallel) thread seals when fully tightened onto the rifle as the O'Ring will be compressed to the
shoulder and thus sealed.

But when this BB sealing nut, supplied by Theoben when the rifle was purchased,is fully tightened up there is a gap to the O`Ring?
(see attached photo)



So how does that work then?

Colin.

[Ca_Varminter]

Well the other way you make a seal with Straight Threads....
The use a nylon or Acetal/Delrin washer to seal on the top surface of the BB valve...
This method of sealing is also use in some Fill adapters....


Stuart

[ColinH]

Ahh Stuart I think you've got it!

When you suggested this I took off the blanking plug at in the bottom is a white seal that looks like plastic. I assumed that there was a gap tat the bottom of the nut but guess the bottle face seals on this.

OK now I understand and thanks for your help Stuart.
C/

[angrybear]

OK thanks for clarification Stuart.

I can understand how the BSPP (parallel) thread seals when fully tightened onto the rifle as the O'Ring will be compressed to the
shoulder and thus sealed.

But when this BB sealing nut, supplied by Theoben when the rifle was purchased,is fully tightened up there is a gap to the O`Ring?
(see attached photo)



So how does that work then?

Colin.

Those caps aren't designed to seal, they're designed to protect the valve & thread,
the last thing you want is to unscrew a nut with 200+bar behind it     
If the valve leaks it needs replaceing/repairing.

[Ca_Varminter]

Well ... These Caps were made to protect and seal the BB Valve...
This why they were Hexagonal, so you could use a spanner to tighten and remove them.
Also there was very minimal volume in the neck and valve area.
Also the cap had plenty of thread engagement.
So a slight turn would gently release the pressure...

Stuart

[ColinH]

OK thanks for clarification Stuart.

I can understand how the BSPP (parallel) thread seals when fully tightened onto the rifle as the O'Ring will be compressed to the
shoulder and thus sealed.

But when this BB sealing nut, supplied by Theoben when the rifle was purchased,is fully tightened up there is a gap to the O`Ring?
(see attached photo)



So how does that work then?

Colin.

Those caps aren't designed to seal, they're designed to protect the valve & thread,
the last thing you want is to unscrew a nut with 200+bar behind it     
If the valve leaks it needs replaceing/repairing.

Thanks for the reply angrybear, but now your comment has thrown me into total confusion.

When I brought the gun in 1999 I was supplied with this sealing nut and I am sure the documentation described it a a "sealing nut" to prevent leaks if stored off the gun. If it was just to protect the threads why would Theoben make it from steel and add a plastic sealing cap at the bottom of the nut?
I`am not an expert in pneumatics but if the leak from the valve was that bad surly it would all discharge before tha nut could be fitted?   

Additionally, the bottle supplied separately had a red plastic screw on cap that was described as a "protective cap" for the threads and valve.

Confused of Exmouth !!

[ColinH]

Well ... These Caps were made to protect and seal the BB Valve...
This why they were Hexagonal, so you could use a spanner to tighten and remove them.
Also there was very minimal volume in the neck and valve area.
Also the cap had plenty of thread engagement.
So a slight turn would gently release the pressure...

Stuart

Thanks for replying Stuart.

Well that was my understanding as well, ie the steel hex sealing nut prevented any leaks until fitted the bottle was fitted to the gun, and the red plastic cap was to protect the threads from dust and damage.

C/