Pressure testing using a trace of refrigerant.

[crit71]

Now then...........here's a question thats recently raised its head and I cant find a definitive answer.
If, after exhausting all other methods, can a trace of refrigerant be added to a system before OFN to pinpoint a leak. I'm not talking about KG's either. Just a sniff, lol. I know its acceptable, under the fgas regs to add refrigerant to a system with a known leak if it means dire consequences as a result of failed A/C or refrigeration equipment:eek: But not really very clear on the pressure test thing. Since fgas is all about refrigerant contaiment I'd guess the answer would be NO.
But if the leak is not found, then more refrigerant would be lossed over time.....please help. Thanks, Chris.

[Contactor]

As you say it's not allowed to add refrigerant into a system known to be leaking.

Therefore use this method before you are certain the leak is present.

[sedgy]

hi crit, on a basic system you have an evaporater, a condencing unit , and the pipework, that if you pressure test < with ofn< you should find the leak on one or 3 parts of the system , best of luck,

[monkey spanners]

If you have a system with a leak, and you recover all the refrigerant down to 0psi, so as not to suck in any contaminants, when you puff it back up with some ofn its already got a trace in! If this don't work it comes down to chopping the system into sections to pressure test individually, and if the leak still can't be found its new system time!

[multisync]

As you say it's not allowed to add refrigerant into a system known to be leaking.

Therefore use this method before you are certain the leak is present.

This is a misunderstanding of the regs.

You can indeed add gas to a known leaking system. However you must have an agreed plan for the repair within a reasonable time frame or if the leak is so small it is not economically viable to find the leak....

However leak testing with a trace gas is not deemed acceptable...afaik

[aircool]

if no joy with ofn try helium

[NoNickName]

You can indeed add gas to a known leaking system.

No. Deliberately releasing F-refrigerant into the atmosphere is forbidden. Charging a leaking system equates to deliberately releasing refrigerant.

[multisync]

No. Deliberately releasing F-refrigerant into the atmosphere is forbidden. Charging a leaking system equates to deliberately releasing refrigerant.


From UK F-Gas support:




Thank you for your query.
We are assuming the systems contain HFCs, so the EC F gas Regulation applies. If they contain HCFC such as R22 then please see RAC 8 attached.
Topping up leaky system:
There is nothing in the EC F gas Regulation that states that it is permissible to top up a RAC system twice before other action is taken.
The Regulation does not specifically state that to top up a system with a known leak is not permitted, this is implied within the key obligations as being against the spirit of the regulation, unless there are technical or economic barriers hindering the repair:
Information sheet RAC 3 (attached) contains wording direct from the EC F gas Regulation which states one of the key obligations for operators of equipment containing HFCs must: ‘’ Using all measures which are technically feasible and do not entail disproportionate cost operators must:
(a) prevent leakage of F gas refrigerants and
(b) as soon as possible repair any detected leakage.’’
This is detailed in Article 3.1 of the EC F gas Regulation (copy attached) and is enforceable in GB law, see GB regulations 2009 SI 261 (also attached).
There is no absolute period of time specified within which a leak must be repaired, it needs to be as soon as possible within the caveats of technically feasible and not entailing excessive cost, which is for the operator to decide and can only be tested in the courts should a prosecution for non-compliance be brought about.
Therefore it is for the operator to decide, drawing also upon expert advice from the contractor, whether it would be technically or economically unviable to repair the leak immediately if proving problematic to locate and/or whether the system could be topped up with refrigerant whilst this process was taking place. It is our view that if the operator requests top up of a leaking system, that it is only undertaken if a plan for repair of the leak which suits both the operator and contractor is scheduled for the first reasonable opportunity.
We have previously supplied the following advice on disproportionate cost which may be of interest to you:
If there is a large leak logically it must be dealt with very quickly. Otherwise you might lose the whole refrigerant charge before you came back to do a repair. This might be compared to a large leak from a water main – it must be dealt with as an emergency.
Shutting the plant down would not necessarily help – the leak will probably continue during a shut down (indeed for a leak on the low pressure side of a refrigeration plant the leak rate might increase if you shut the plant down!). Shutting down and isolating the part of the plant that is leaking might help, but not all plants have isolation valves to make this possible or safe.
Also, with a large leak, there is no issue of excessive cost. If the leak is allowed to continue, the refrigeration plant will lose so much refrigerant that it will not work – so you have to spend money to repair it whether you like it or not.
At the other extreme, a very small leak would not need such prompt action and, at some very low level of leakage may either be un-repairable or very expensive to repair (in relation to the value of the environmental benefit). As an example imagine a plant with 10 kg of HFC refrigerant. With a very sensitive leak detector you find a leak of 10 grammes per year. It would take 100 years to leak 1 kg. It is likely that repairing such a tiny leak does entail disproportionate cost. Leaks of such a tiny size can be noted and might be dealt with at the next major overhaul when the plant is shut down for other reasons.
The problem with these 2 extreme examples is judging where there is a "cross-over" in terms of disproportionate cost. This is not a clear cut answer as there is no set level of what is excessive costs and would be based on the individual company looking at their financial position. Defra’s advice is that it is for the courts to decide what would be excessive costs. It is for you and the customer need to make a decision based on the guidance above with the aim of the EC F gas Regulation in mind.
Leak checking with UV dye
As long as the guidelines in supporting Commission Regulation EC 1516/2007 on leak checking are adhered to, then it is for the qualified personnel undertaking the work to utilise their skill and experience to determine the most suitable method and procedure on a case by case basis.
The Regulation does not go into detail of the procedures, but you will see that this method is listed as an acceptable direct testing method in Article 6 of the Regulation. Certain articles in the Commission Regulation also refer:
Article 5.1 allows both direct and indirect checks.
Article 5.2 requires direct checks may always be used.
Please also note that this work must be undertaken by personnel holding a qualification that covers them for breaking into the refrigeration circuit. i.e. personnel holding a Category IV F gas qualification (leak checking) would not be sufficiently qualified to do this work.
EC 1516/2007 Article 6
Direct measuring methods
1. To identify leakage, certified personnel shall use one or more of the following direct measuring methods:
(b) application of ultraviolet (UV) detection fluid or suitable dye in the circuit;
3. The application of UV detection fluid or suitable dye in the refrigeration circuit shall only be undertaken if the manufacturer of the equipment has approved that such detection methods are technically possible. The method shall only be undertaken by personnel certified to undertake activities which entail breaking into the refrigeration circuit containing fluorinated greenhouse gases.
Nitrogen or other means such as use of soapy water would be the preferred methods to determine a leak, but the EC F gas Regulation does not specify which methods should be tried first.
This use of a small amount of refrigerant mixed with other gases for use in leak finding in either mobile or stationary air conditioning is not specifically banned under the EC F gas Regulation although knowingly venting F gases to atmosphere would not be in the spirit of the Regulation. This use may be considered to be beneficial as it results in less F gas being lost to atmosphere overall. It is our opinion that the gases should be recovered as required by Article 4 of the regulation if technically and economically feasible.
Please see sheet RAC 6 and EC 1516/2007 (attached) for further detail on leak checking.
We hope that the information provided answers your query. If not, and you require further information, please do not hesitate to contact us again (details are at the bottom of this email).

Kind Regards,

Lucinda

[Quality]

F gas Support is very good if people are bothered to use it

[multisync]

F gas Support is very good if people are bothered to use it

We have used them when certain technical queries need clarification. That email was as a result of our customer being told that it was acceptable to top up twice before PLT. Not having heard of this 'reg' we carried out due diligence and this is the reply...

It helps engineers who when faced with a freezer full of food (and a SOG situation) their responsibilities and by implimenting a correct proceedure won't simply resort to the easy out "Sorry mate no can do" which leaves the customer with a freezer full of food going off

[NoNickName]

Unless Lucinda's opinion is the European Parliament's opinion, it is still forbidden to deliberately charging F-gases for tracing leaks.

[crit71]

Thanks multisync. It would appear from that response that its acceptable after exhausting other methods first. Would you agree?

[multisync]

Thanks multisync. It would appear from that response that its acceptable after exhausting other methods first. Would you agree?


Not for me to agree -it's for the judge to agree.:cool:

However if you can show/prove you acted with due diligence then I would hazard a guess that they would not prosecute..

[multisync]

Unless Lucinda's opinion is the European Parliament's opinion, it is still forbidden to deliberately charging F-gases for tracing leaks.

We shall contiune to act acording to the professional advice we are given...

[Brian_UK]

As a non-legal techie reading the above and following comments I would agree with Multisync.

If you have refrigerant in the system, it is running, and you add refrigerant to keep it running, until repair, then that it acceptable.

However, with an empty leaking system to then add refrigerant, for leak testing, which is intended to leak to atmosphere goes against the regulations.

There are other methods and they should be investigated.

In holier than thou mode, we might say, "well it's only a few grams", but if everyone used these few grams then it adds up to quite a bit of gas being blown away.

[Sits in corner with fireproof suit on]

[Quality]

As a non-legal techie reading the above and following comments I would agree with Multisync.

If you have refrigerant in the system, it is running, and you add refrigerant to keep it running, until repair, then that it acceptable.

However, with an empty leaking system to then add refrigerant, for leak testing, which is intended to leak to atmosphere goes against the regulations.

There are other methods and they should be investigated.

In holier than thou mode, we might say, "well it's only a few grams", but if everyone used these few grams then it adds up to quite a bit of gas being blown away.

[Sits in corner with fireproof suit on]

Its not a question of agreeing with folk but complying with legislation
I do work and earn my living in the real world but top up a half meg-watt plant - and its more than a few kilos its all about the cost and of what is being spoiled, we need (we the industry) some enforcement

[Brian_UK]

^^ Very true, but when the legislation is unclear and untested we seem to have to make judgement calls on things like this.

[Quality]

its sensible and professorial to go by the book - but I must comply as the regs state -- but I totally agree with your comment

[aircool]

what is the point of f-gas then,we can have it both ways...correct me if i am wrong,but these regs don,t apply to china and india and the other developing countries right..another money making scheme i take it.why not ban all flares and make all connections brazed.the list goes on