Pressure testing for leaks on split a/c systems

[chemi-cool]

Not so long ago I was talking to a young fridge engineer from another company.
He had been on a course where the lecturer. Said he must carry empty vacuumed out cylinders.
So that when he is left with the small amount of low pressure vapour in his gauge lines.
It can be purged into a virgin cylinder!!!!

It made me laugh.

Lecturers in colleges and university, are the people with the least experience in that field,

NO ONE IS SMARTER THEN US!!

Even that unexperienced lecturer forgot to think about the probability of using different types of refrigerants....

Stupidity is the only thing on earth that makes me mad

Welcome back Viking.

[sinewave]

Yes, welcome back Viking!


Glad to see your website back on-line too!

[B G Scott]

It made me laugh.

Lecturers in colleges and university, are the people with the least experience in that field,

NO ONE IS SMARTER THEN US!!

Even that unexperienced lecturer forgot to think about the probability of using different types of refrigerants....

Stupidity is the only thing on earth that makes me mad

Welcome back Viking.

Those that "can" DO,
Those that "can't", TEACH
Those that "can't teach" TEACH TEACHERS.
I know it's an old quote in the teaching (profession)( I use this term lightly) but there is an element of truth in there!!

[lomb]

What sort of oil should one be using on r410a to oil the back of the flare(not fit surface)?I have tried to find a supply of a small amount of POE oil but cant. I persume i shouldnt use PAG oil for r134a systems? And if not why not as if not applyed to the fit surface of the flare it shouldnt enter the pipes and damage the unit.Do the manufacture torque values still apply when oiling the flare as persumably if wet one can apply a higer torque.

Also when making the flare some say to oil the fit surface,is this really required and do people then clean this off before torqueing up. Thanks
Thanks

[flyinkiwi]

Agree - Leak lock = You're a ****e Fridgie... or you're a sparky.

Fujitsu General have issued a bulletin, stating that pressure testing with dry nitrogen is not to exceed 200psig - there have been incidences of nitrogen leaking into the OD unit.

This weakness in the valve is sometimes caused by the distortion of the valve body when the flare is tightened (yes, even with 2 spanners) - I've also struck a panasonic that was like this too.

[taz24]

.

This subject has been discussed for a few years now and it is still causing problems .

I was speaking to a manufacturer a few months back and he was confident that no valve
and flare would leak if used and done correctly.

When the final flare was fitted, using torque spanners the flare would never leak and after
the flare was fitted the service valve needs retightening to ensure that it is sealed.
The fitting of the flare and the stress that, that incurrs is what could cause the valve to pass.

So fit the flare correctly and then reseat the valve to ensure it does not pass, that in the words
of the manufacturer will garentee a correct fitting.

taz.

.

[lomb]

So is use of oil a good idea and if so should it only be on the back to let the shoulder of the flare not catch on the nut? Can a small dot of vac oil be used as it shouldnt enter the system?

[lomb]

Agree - Leak lock = You're a ****e Fridgie... or you're a sparky.

Fujitsu General have issued a bulletin, stating that pressure testing with dry nitrogen is not to exceed 200psig - there have been incidences of nitrogen leaking into the OD unit.

This weakness in the valve is sometimes caused by the distortion of the valve body when the flare is tightened (yes, even with 2 spanners) - I've also struck a panasonic that was like this too.

If that is the case then whats the point in testing with OFN at all? Running pressures are 400-450 psi.