R507 refrigerant gas

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Deck Plate Wanderer
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R507 refrigerant gas

Postby Jon » Wed Nov 13, 2013 3:20 am

I'm currently working offshore on a pipe lay ship, our provision refrigeration plant has a leak that we are searching for.The system is charged with Unicool R-507 refrigerant. The only test equipment i have on board the ship is a unitor dye tracer fluid and uv light. These might be stupid questions but I don't have many KG of spare refrigerant onboard and i need to find the leak.

First off, with the tracer fluid that is in the oil - Will that pass through the oil separator so we can see leaks in condenser/evaporator lines or does the oil seperator take the tracer fluid out of the refrigerant with the oil so it can only help for looking for leaks on the compressor itself?
Second, If i was to purchase a electronic leak detector, what would i need to purchase that works with 507 refrigerant? Im getting mixed results on the internet and im not sure what I need.
Am i correct in saying R507 is a blend between R0143A and R125, both which do not contain CFC's or HCFC, so a halide leak detector would not work with this?\

Let me know if im way off on this..hahah....Im just desperate for some help here now because i couldn't find a leak with soap and water or the tracer fluid and uv light.

Deck Plate Wanderer
Posts: 24
Joined: Tue Sep 10, 2013 9:47 am

Re: R507 refrigerant gas

Postby EvenKeel » Wed Nov 13, 2013 2:25 pm

From what I have read, the dye makes it through the entire system and will remain until the oil is changed.

http://www.mt-online.com/march2000/fluo ... rant-costs

http://www2.dupont.com/Refrigerants/en_ ... idance.pdf

Also from what I have read, most of the new electronic leak detectors that can sense HFC's like R507 would work for you.
If you are in North America, Acklands-Grainger can get you one for about $500. The one on the link below specifically mentions R507. It is made by UEI Test Instruments.

https://www.acklandsgrainger.com/AGIPor ... e=WWG6CMT7

Also had a look at the pdf's for the Yellow Jacket detectors and they both list R-507 as a detectable gas for their analysers.


Acklands has them as well but if you are international, the reps are on the link below:


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Big Pete
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Currently located: Solihull, England

Re: R507 refrigerant gas

Postby Big Pete » Thu Nov 14, 2013 6:04 am

Hi Jon,

On fridge compressors the suction gas passes through the crankcase and is saturated with oil. The oil seperator only removes droplets of oil, there is a lot of vapourised oil going round the circuit. If you have a small leak for a long time, often the easiest way to find it is to look for a little pool of oil and follow its path upwards, to its source.

Spraying soapy water (ordinary washing up liquid shaken up with water and applied with a paint brush or using using one of the pump action bottles used for domestic cleaners) over the pipes and fittings works well, the leaks blows nice big bubbles. But not so good on the electrical bits, solenoids etc.

It is difficult to detect leaks in the evaporator because the fan is blowing the gas everywhere. If you have a major leak there, an Electronic sniffer will detect the gas in the room but it is very hard to pinpoint without removing the entire evaporator and putting a pressure test on it.
Sometimes you can have a leak hidden behind the Bulkhead panelling which will be very hard to find.
Dont forget to check inside the pressure switches on the compressors, if the pipes are not correctly tightened to these (one spanner on the hex on the switch on on the nut) it is very easy to crack the bellows inside the switch and it can be hard to spot the leak.
Another place where it is difficult to spot a leak is the cranksahft seal, the airflow from the drive motor disperses the gas, however, in this case it is usually easy to see the oil leakage below the seal.

Good luck.

It is always better to ask a stupid question than to do a stupid thing.

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