[AT] Russian Metric uses BSPP was Thought to ponder

[bloomis at charter.net]

John's experience is the same as mine. All the European wine equipment are
metric, DIN, and IEC components but all the pneumatic and water fittings are
usually plain ol' NPT. I initially expected 'metric' pipe. No such animal.
An exception are DIN fittings which are in MM. But those same DIN ends and
nuts were used on inch size stainless sanitary tube. BSP is the PITA of the
lot. One Italian company, a DE filter, used 80 DIN (3") non-taper ball
valves with BST. From the factory the threads are wrapped with what looks
like oakum and those suckers are tight. There's something from the dark
ages. Perpetually difficult to get to seal and trying to orient the valve
handle in a useful place was difficult at best. Solution? Cut the straight
threads off and weld on I-Line fittings, which 99% of hoses and fittings are
in a winery. That or TC. Then a valve can be replaced in one minute. 
Brad

-----Original Message-----
From: AT <at-bounces at lists.antique-tractor.com> On Behalf Of John Hall
Sent: Sunday, May 12, 2019 5:08 AM
To: at at lists.antique-tractor.com
Subject: Re: [AT] Russian Metric uses BSPP was Thought to ponder

I've got 30 years in a machine shop and have yet to see a metric pipe
thread--because it doesn't exist to my knowledge. We do a lot of German and
Japanese work, it is always British pipe thread, either tapered or straight.
The whole planet seems to scream at the US to go metric, but they haven't
developed a metric pipe thread. Yet all "normal" threads are 60 degree V
thread form, but the British pipe are 55 degree. 
Furthermore, it depends on what country is building the piece of equipment
as to the actual designation of the thread on the print--Trust me, no blue
print ever made it so simple as to say "British pipe thread". There are 3 or
4 accepted/common designations for British pipe threads.  It is a mess of a
system to say the least.

John Hall


On 5/12/2019 7:11 AM, James Peck wrote:
> I added  an oil pressure gauge to my long gone 80 VW. I used a 1/8  BSPP
to tube fitting from the Festo product line into an already tapped port on
the block. That is when I learned that German metric uses BSPP straight
thread fittings. I had not known that Russian metric did the same. We have
discussed that Belarus is not Russian but I bet the practice came from the
Soviet era.
>
> Later, I worked for a company that used BSPP fittings on the hydraulic
lines to shift Reaction Injection Molding mix head plungers.
>
> Sometimes people use Teflon tape on the straight threads not knowing that
all the sealing is done by the o ring.
>