which Leak Detection Dye ?

[pomdekiwi]

Hi All need your advice..

Work in the food industry (fruit ripening) and have evaps in roof voids above the cold rooms.Large fans draw the cooled air down to the fruit and return it via damperd slots to the the evaps, Not sure if you really needed to know that much but "Hey" not posted before so i'm making the most of it lol

My problem is that the evap coils are starting to leak (for reasons i'll spare you) and i'm spending a lot of my time on my hands an knees trying to find the leaks with the ol "Nitro" at 250psi+, a puff of fridge still in the system and the electronic sniffer,sopy spray a good torch and lots an lots of patiance..trouble is my boss an client don't have any.

Would it be better to start injecting the systems with a cloloured dye an if so are there any that can be used without the ultraviolate light system an lastly who does the best deals as its really expensive stuff.

Most of my units take about 7-12 Kilos and are generally R22.407C 0r R404

Many thanks for ya help guys

Pom (Steve)

[chemi-cool]

This is a small system, soap will do.
Bare in mind that you need different dye for synthetic oil and a different one for POE oil and its also not cheap.

[pomdekiwi]

Thanks for the reply mate

Perhaps I should have also mentioned that the roof void contains two evap coils and i can never tell which has the leak as they are both on the same liquid and suction feeds with no way to separate them from each other,My train of thought would be that i would spot the dye in the drip tray of the unit with the leak an so half my search time. the thing is i cant always see or hear the leak but just know its on the coils because the pipework and condensercan be isolated.

I have seen some green dye leaking from a system which definately identified the leak immediately and could be seen without need for altraviolet light.

Cheers again

Pom (steve)

[chemi-cool]

Yes, there is such a thing.

thought would be that i would spot the dye in the drip tray 

You need to know the exact spot.

Concentrated soap makes big bubbles.

[Radiohead]

install ball valves in liquid & suction lines and pressure test each evap coil. vac test & micron gauge will soon let you know which coil is leaking ( taking its on the evap coils?? ) OFN & spray will do the rest, though it might not be on the outer edge of the coil... enjoy!

[nike123]

Try to get this soap solution. Best in our business.

[philfridge]

My problem is that the evap coils are starting to leak (for reasons i'll spare you)

Leak testing equipment is not a quick process, and if the evap coils are starting to leak as you say why cant you fit new evap coils ? or repair the leaks as you seem to have identified the leak in this area . I would not bother with the dye as it is waist of time and money. Why not get yourself a better electronic sniffer be money well spent .

[pomdekiwi]

The point of this post was (an thanks for all your comments chaps) is that the dye would identify which of the two evap coils are leaking immediately.On two occasions of used soap and electronic leak detection and not found the leak and been at it all bloomin day. I was at another building which had- had this stuff in and identified the leak immediately. I have hundreds of these damn units all over the country, If i can find the leak area i can repair it to give the client breathing space but just writing off the unit cos i can't find the leak is getting frustrateing.My lectronic leak detector is a good one and has been calibrated so i know its good an generally so are my search for leak skills but these units arnt the easyest to get to as they are three tubes deep.
Its a long post again but its not as cut an dry as it first appears.
Pom

[US Iceman]

Usually if you have a leak you will also find an oil stain around the leak. Evaporators are bit more difficult because they are wet (sometimes all of the time depending on the application).

If the leaks are not at the return bends on the coil, around the TXV, or pipe joints (brazed or otherwise), then the only easy places left to look are on the penetrations through a wall or where tubing has rubbed against something else.

If the leaks not in one of these places, it probably in the coil where you can't get to it anyway.

On a side note: if the coils are springing multiple leaks on a regular basis due to something (age, acid from fruit, etc) it's going to be cheaper to replace the coils than the continued call-backs and unhappy customers (and boss). Sometimes you just have to give in and replace the equipment.

[icecube51]

if you can separate 1 coil to repair it, do a pression test at 35 Bar / 500 PSI,(N²) so if there is a weak spot, it will give and you can repair it straight away.

better than to come back every week and do the same s****t alover again.

Ice

[philfridge]

The point of this post was (an thanks for all your comments chaps) is that the dye would identify which of the two evap coils are leaking immediately..My lectronic leak detector is a good one and has been calibrated so i know its good an generally so are my search for leak skills

If you believe this then go and spend up to a hunderd pounds on dye for each of the leaking units. Advise has been given on best leak detection.

[pomdekiwi]

Phil fridge ..thanks for the stab in they "advice" about just going and buying dye but if could bring you guys back to the title of this post it was which leak detection dye !
I did also mention that i have a load of these units and its difficult to explain the actual set-up which is what i was trying to spare you all with the details.
All it was guys was ..
Never used a dye at all but somone had put the stuff in one of my units in another factory an i found the leak instantly an was able to establish that the unit was beyond repair within the hour,so i thought perhaps it would be an idea to inject them all an have done with it so i wrote on here to see if anybody had any idea of which product was the good value.

its not always easy to express onself in written word but i try my best.

POM

[WINJA]

that spectraline uv dye is really good , i just bought a cheap led uv light to use with it and it works great, i had trouble with the earlier spectraline product from the mid 90s some of it crystalized or turned to gel in the capsule , but its been good for the last ten years or so

[kiwireeferman]

that spectraline uv dye is really good ,

To my knowledge this is the only product that has been OK'd by a number of OEM's.

And is the only maufacturer that has put considerable effort in this technology.

[pomdekiwi]

A huge thanks to All for all the advice but especially to WINJA and KIWIREEFERMAN for comming up with the goods,
Thanks Guys

Pom

[nevgee]

Yellow Jacket / Ritchie do a dye which is universal and suits all types of oil. We use it in swimming pool dehumidiers where we tend to get out of place leaks. however, as stated above the usual traditional methods of leak detecting are also used. The dye has proven in our cases to be very useful and shows leaks that are not always so obvious.
Typical application rate is 15ml per gallon of oil.
(We assume the gallon is US and not Imperial our gallon being larger than the Yanks ... x 1.2)
But typically any system from 5 up to 11kg gas would take 15ml of dye.

Not expensive in the grand scheme of things when you consider the time it saves.

[WINJA]

Ive been using one of these UV led keyrings for a long time with great success , the led light offers a better spread of light than the ones the dye companys offer , also they are less than 5% of the price and the batteries last for 40 hours and the led bulb lasts 100,000 hours , works ok outside in daylight with a black umbrella , if you need something more powerfull the energy saving uv bulbs fit straight in your mains powered hand held inspection lamp, dont buy the normal blacklight light bulb they are not true uv must be the longlife compact fluro type bulb, only cost me $15 and lasted 4 years