Threads

[M1JWR]

Hi all
would anybody have any idea what threads these would be one pic is the item in the middle its an allen key bung taken from the nrv on a broomwade and the nut in the other is from the head decompressor on the same, pics are taken with quarter in bsp 3 way and a standard modern 6mm threaded bolt for comparison, ideas appreciated.

 

[mike 109444]

Well in the top pic the plug is probable an 1/8 bsp.
Not to sure yet on the nut in second pic.

 

[Hopefuldave]

Have anything to measure the threads?

Dave H. (the other one) (Keen on Metrology)

 

[M1JWR]

thanks, hang fire, i will put on another pic of spare decompressor bolt end so to speak with a tape measure

 

[M1JWR]

here we go, advised to do away with all old valves and guvnor and connect pressure switch to nrv
need the bigger threaded bits for stop bolts in cilinder heads

 

[mike 109444]

Does the 1/4 bsp thread sit in the same pitch as the nut, if so then it should be 3/8 bsp as both 1/4 and 3/8 bsp have 19 tpi

G1LXC....

 

[brightspark]

just cut the rods off decompressors and screw them back on

 

[mike 109444]

What I meant by the above was to use the 1/4 bsp T fitting as a thread gauge.
Not sure what the rest of what you are up to is...
plugging up the old holes ?

 

[M1JWR]

What I meant by the above was to use the 1/4 bsp T fitting as a thread gauge.
Not sure what the rest of what you are up to is...
plugging up the old holes ?

Have new switch as old one was knackered which is modern set up with built in unloader valve so the idea is to connect new unloader to nrv on main feed pipe, that is where the 1/8 plug came from.
after that the decompressors will of no use any more and they are in good condition so dont want to cut them up, they are linked together in top of the heads then go to guvnor which is a thing i have no clue about.
and it may have become faulty as comp dosent function correctly with the old system it appears, as it works to 50psi'ish and cuts out on new switch, if i dont use any air and wait 30 secs or so i can switch it on again
and it will go up to 80 psi'ish and so on, tho i remember recently one time i switched it on and it went to around 100 psi and then cut out, so the idea is to convert it to a modern way and see if it stops the 30,40, or 50 psi at a time senario.
the unloader in the new switch is not currently connected, sorry how i explain things, better with numbers than words, regards john

 

[mike 109444]

Stick some pics up of the set up

 

[mike 109444]

Bare in mind that the unloader part of the pressure switch is to dump the air trapped in the pipe between the out put of the pump and in put to the tank so that when the pump starts up again (after using some of the air in tank) it pumps in to the pipe that has no pressure from the tank to work against until it builds up enough pressure (and momentum/speed) to overcome the non return valve and start to fill tank again. reason yours might be stopping at 50 ish is because it is fighting the pressure in tank due to non working nrv. Then after 30 seconds the pressure in pipe drops enough for pump to get going.

 

[M1JWR]

sorry for delay some pics as requested, that nrv might be a bitch to get out could i feasably put another on top of it if i cant get it out!!!

 

[frank horton]

is there a model engineer or a proper engineering firm near where u are ?
I'm sure someone would measure the thread for u.......
even a B+Q if u think it's a BSP....
I'd be happy to do it but I live a 1000 miles away.....even make the new bungs.......
wherever the debatable lands are ??

 

[M1JWR]

live near carlisle, good local hydraulics place there, they have everything, got some stuff this morning
1m 6mm pipe, elbow 1/8th to 6mm and the stop bolts 3/8th bsp also a 1/4 in stopper for front connection on tank
only thing i diddent get was a nrv as it will be hard to get out and diddent know thread size, need stilstons, guy did say i could
put another on top and make copper feed pipe shorter to fit if it came to that if i couldent get it out, they have new ones all shapes and sizes.
and yes 4's do rule 20 year old xjr1200 here and had kwak z1000j before that !!
The debatable lands are england scotland border, border reivers, bonnie prince charlie all that, they were called that because it was debatable if it was england or scotland

 

[M1JWR]

got the nrv out,its a biggie

 

[M1JWR]

Progress, checked nrv,nowt wrong with it, took de comps and guvnor off put "bungs" in where needed and plumbed up with
the new stuff in the suggested way, did the same thing, back to the drawing board.
next suspect, pressure switch as its never "cut in", took it back to shop and said it was faulty, which it probably was, exchanged
it for a new one that does 10 to 16 amp plus a little extra £'s of course, as the previous one was 6 to 10 amp and the old one was 9 amp
this would give me room to play with.
to start with because the previous one failed at 10amp setting i thought it hadent enough beans, so set this one to 12 amp, twice i fired up comp from empty
one time i switched it off manually at 130psi so i turned the screw back two turns, try again from empty, this time went just past 130psi and safety blew off,
so too many beans from what could be a good pressure switch, so put it back to 10 amp and adjusted screw up one turn, start again from empty, this time
it went to 100psi'ish and switch cut, and blew through unloader in normal fashon,could be getting nearer to a result now, hopefully.
cannot report anything with cut ins yet, time will tell, seem to be a bit complicated these condor switches.
thats it for now , other things to do