If a valve is marked as having a 1/4" BSPT fitting, is that a taper fitting
? Must one be used or is a normal fitting OK ?

"G&M" wrote in message
...
If a valve is marked as having a 1/4" BSPT fitting, is that a taper
fitting
? Must one be used or is a normal fitting OK ?

If it's for gas (which a lot of taper fittings are for) then I'd say yes it
must be taper. Ditto for steam, compressed air or anything else dangerous.

Otherwise if it fits and works, OK.

G&M wrote:
If a valve is marked as having a 1/4" BSPT fitting, is that a taper fitting
? Must one be used or is a normal fitting OK ?


BSPT is indeed a taper thread - BSPP is a parallel thread (though often
both get referred to as BSP). I was always taught:

BSPT female with BSPT male = ok (with sealant on thread)
BSPP female with BSPP male = ok (uses bonded seal or fibre washer or
similar to seal)
BSPP male with BSPT female = ok (with sealant on thread)

Anything else = not ok

That's what the guys that taught me hydraulic systems design said
anyway. The guy that taught me plumbing said that anything will seal
with enough hemp and snot ;-)

HTH,

Chris.

--
cut along the dotted line to reply

"Chris" wrote in
message ...
G&M wrote:
If a valve is marked as having a 1/4" BSPT fitting, is that a taper
fitting
? Must one be used or is a normal fitting OK ?


BSPT is indeed a taper thread - BSPP is a parallel thread (though often
both get referred to as BSP). I was always taught:

BSPT female with BSPT male = ok (with sealant on thread)
BSPP female with BSPP male = ok (uses bonded seal or fibre washer or
similar to seal)
BSPP male with BSPT female = ok (with sealant on thread)


It's for oil. BSPP male into BSPT female which you seem to say is OK.

Thanks.

G&M wrote:

It's for oil. BSPP male into BSPT female which you seem to say is OK.

Thanks.


Agggh!! Sorry, what my brain meant to type was BSPP female with BSPT
male is ok. Unfortunately my hands weren't listening. It wasn't til I
saw your reply that I realised. Apologies.

BSPP male with BSPT female is not recommended because you do not get
very many threads engaging, particularly a problem with harder materials
(eg plated steel) / higher pressures.

Apologies again for the confusion.

Chris.

--
cut along the dotted line to reply

G&M wrote:

It's for oil. BSPP male into BSPT female which you seem to say is OK.

Thanks.


Agggh!! Sorry, what my brain meant to type was BSPP female with BSPT
male is ok. Unfortunately my hands weren't listening. It wasn't til I
saw your reply that I realised. Apologies.

BSPP male with BSPT female is not recommended because you do not get
very many threads engaging, particularly a problem with harder materials
(eg plated steel) / higher pressures.

Apologies again for the confusion.

Chris.

--
cut along the dotted line to reply

"Chris" wrote in
message ...
G&M wrote:

It's for oil. BSPP male into BSPT female which you seem to say is OK.

Thanks.


Agggh!! Sorry, what my brain meant to type was BSPP female with BSPT
male is ok. Unfortunately my hands weren't listening. It wasn't til I
saw your reply that I realised. Apologies.

BSPP male with BSPT female is not recommended because you do not get
very many threads engaging, particularly a problem with harder materials
(eg plated steel) / higher pressures.

As you say agggh. But many thanks for pointing it out before I made a
potentially fatal mistake.