Can anyone please help?

[geraray]

Can anyone please let me know what are the average pressure test to be applied to a large refegeration system to make sure no leaks are in the system and also the time duration to leave the system under pressure while testing?

Many thanks,
Ray

[Clk320_Greg]

It vaires from engineer to engineer, check the install manuals with the units to ensure you reach at least there minimum and document it incase of a warentee claim.

[taz24]

Can anyone please let me know what are the average pressure test to be applied to a large refegeration system to make sure no leaks are in the system and also the time duration to leave the system under pressure while testing?

Many thanks,
Ray


It depends on the refrigerant and type of system.

A large refrigeration system with a high and low side would be tested to (EN378 standards) the pressure that equals the refrigerant saturation temp of 32 degC and 55 degC respectively.

So the high side would be tested to a 55 degC
the low side to 32 DegC and then left for a minimum of an hour but 24 hours would be better or a week would be better still.

If it was a air conditioning system or heatpump then the test pressure is the same throughout at 55 degC.

R22 at 55 deg C = 22bar
R404a at 55 degC = 26bar
R410a at 55 degC = 34bar.

So no one answer.

To confuse the mater further that is the leak test pressure if you want to prove the system is safe then you times the pressure by 1.3 to find the strength test pressure and you only hold that in the system for about 30 seconds before releasing the pressure to the leak test pressure.

Are we confussed yet :p ;)

taz.

[joe magee]

100 to 150lbs of nitrogen overnight should do. Why the complicated answers?

[geraray]

thanks ppl, have taken some considerations from what you told me and I think customer should be quite happy.
Ray

[mbc]

What I do Before I go for high pressure I start with low one ( 2 bars for one hour ) then I go for medium one ( 7 bars for min 2 Hour ) then I test in high pressure . it is more safe during test time.

[taz24]

100 to 150lbs of nitrogen overnight should do. Why the complicated answers?


Why the complicated answers??

I'm not sure which way to take that responce but I will give you the benifit of doubt and explain to you "Why the complicated answers"?

In the UK we are part of Europe.
We have certain standards that we work to.
These standards ensure systems do not leak or worse, go PoP if over pressurised.

So its not over complicated its because we work to good industry standards.

taz.

[750 Valve]

Same, in Australia we have a code of good practice and a set of minimum standards (Australian Standards) that we work to. Some choose not to but the majority do.

[rubik]

on a new instal i will pressure test overhead to 300 psi prior to attaching any evaps to system. leave overnight and check pressure in the morning. usually it'll be down to 285#-290#. check again in afternoon the pressure should have risen back to around 300. if it is anything above the 285-290# of the morning you have no leaks.

[nevgee]

on a new instal i will pressure test overhead to 300 psi prior to attaching any evaps to system. leave overnight and check pressure in the morning. usually it'll be down to 285#-290#. check again in afternoon the pressure should have risen back to around 300. if it is anything above the 285-290# of the morning you have no leaks.


I don't understand how you can arbitrarily use a figure of 300psi (20bar) as a suitable pressure for strength testing. What happens if your operating pressure (ps) is greater than this? Then your test pressure proves nothing at all and your testing will be pointless, only suitable for leak test purpose. :eek: Surely the reason to strength test is to prove the system will hold at the max operating pressure. Here in the uk we test at 1.1 to 1.3 times the operating pressure as stated in reply from TAZ.
:)

In UK we're all having to undergo an assesment to confirm that engineers understand the safety aspect and correct method of pressure testing, this process is likely to make a lot of "engineers" sit up and realise they've been doing it wrong. :(

[nevgee]

Can anyone please let me know what are the average pressure test to be applied to a large refegeration system to make sure no leaks are in the system and also the time duration to leave the system under pressure while testing?

Many thanks,
Ray


You didn't state what refrigerant tour system would use ....

[geraray]

My system uses R404, & has been decided to to test at 10bar on the low side and 20 bar at the high side/ for 12hrs. I presume this should do well and if any leaks are present, we should be in a position to confirm that they are there.

[paul thompson]

not enough pressure for a leak test . go by BS 378 en . as quoted by taz ,in an earlier thread . thats what we test to

[geraray]

Oh Paul, I will do that, thanks for the advise.