BSP inconsistency

R

Richard Lindsay

Joined
30 Apr 2013
Messages
27
Reaction score
0
Location
Stirlingshire
Country
United Kingdom
Hi folks,

I’m trying to understand why 2 items advertised as 5/8 bsp are not the same size?

So I have a draft beer system at home and bought a beer keg coupler with threads advertised as male 5/8 bsp(p). In order to attach the beer line to the coupler, I bought an adapter which was advertised as female 5/8 bsp.

When I measure these the male thread is 20.5mm and the female 21.5mm and therefore don’t join

Any ideas?

Thanks for your time
 
You may have two different variations of BSP. The male is described as BSP(p) which is parallel . Your female is probably BSP(t), or taper. You may still be able to mate them, with ptfe or a sealer, depending on the pressures involved.
 
Richard Lindsay said:
Hi folks,

I’m trying to understand why 2 items advertised as 5/8 bsp are not the same size?

So I have a draft beer system at home and bought a beer keg coupler with threads advertised as male 5/8 bsp(p). In order to attach the beer line to the coupler, I bought an adapter which was advertised as female 5/8 bsp.

When I measure these the male thread is 20.5mm and the female 21.5mm and therefore don’t join

Any ideas?

Thanks for your time
Click to expand...
How are you measuring inside the female connector.
 
oilhead said:
You may have two different variations of BSP. The male is described as BSP(p) which is parallel . Your female is probably BSP(t), or taper. You may still be able to mate them, with ptfe or a sealer, depending on the pressures involved.
Click to expand...
I don't think it is at all common to find a female tapered thread.
And I have to say that 5/8" bsp is not a size I'm familiar with either; 3/8", 1/2", 3/4" yes.
 
Black iron or zinc plated BSP fittings are almost always taper threads. Brass is normally parallel. 5/8" BSP is not a common size, but imported equipment often features weird sizes, and American gear uses NPT, which is very close to BSP but has different pitch profiles.
 
If your connectors are plastic (you didn't say) I doubt they are tapered.

Richard Lindsay said:
When I measure these the male thread is 20.5mm and the female 21.5mm and therefore don’t join
Click to expand...

A small male will easily fit into a slightly roomy female.

On parallel thread connectors, the seal is not performed by the thread, but by the rubber or fibre washer.
 
You must log in or register to reply here.
Back
Top