Wheres the leak?????

[monkey spanners]

I have been down on the farm fitting a 30+ year old milk tank with three evaporators and prestcold L200 unit. Put the system on leak test and found one of the txvs outlet connection leaking, fixed with a new piece of pipe and flare.

Left on test over night to find its dropped 50 psi...

Wheres it leaking then guys

Jon

[multisync]

Somewhere near Hungerford?

[australian tech]

1. Any moisture in the system?(it will lower the pressure as the ambient decreases)
2. Are your guages 100%
3. Could there have been any section of pipework that had not equalised.ie solonoids.
4.porousity of evaporater
5.check all valve glands and cap .\
6.Remove any back ground noise. up the nitrogen pressure to 2500kPa ,shut your eyes, listen to units,while slowly turning your head side to side
7. obviously.... eletronic leak detector
.... soapy bubbles
.... ultra violet dye
8 . People often say "It cant just dissapear into thin air!! Well gas does!!

[australian tech]

Also , cows have been known to steal refrigerant. Id question their ringleader. the bull with the biggest horns, and that crazy look in his eye..
"COWS WITH GUNS" DUNT DUNT DAH ..

[The Red Krawler]

I think I'll have to go with your dodgy soldering... sorry :P

[monkey spanners]

Somewhere near Hungerford?

Thats where i've been going wrong, i've been looking for it in Appleton

[monkey spanners]

Also , cows have been known to steal refrigerant. Id question their ringleader. the bull with the biggest horns, and that crazy look in his eye..
"COWS WITH GUNS" DUNT DUNT DAH ..

You might be right there, on of 'em was trying to steal my wing mirror yesterday

[monkey spanners]

I think I'll have to go with your dodgy soldering... sorry :P

Well i'm slightly dissapointed but i admire your honesty

[Karl Hofmann]

There is a black hole somewhere in your pipework and the Nitrogen is leaking into a parallel universe where sadly it is the most toxic substance in the universe and the inhabitants are naturally cheesed off with you and they are amassing a mighty armada to invade our universe. Monkey, you have just started an interstellar war...

[multisync]

Thats where i've been going wrong, i've been looking for it in Appleton

But I'm still the closest so far

[The Red Krawler]

In all seriousness, if its a plate evaporator I'll say its leaking there. If its a finned evaporator, I'll say its return bends have had the solder eaten out. If its a static coil, I'll say the TX flares.

And if its none of those, I'll go back to the dodgy soldering :P

[desA]

Dodgy pipes. Pinhole leak.

[monkey spanners]

As the system has been idle for about 12 months i did wonder if the superheat pixie had got bored with no valves to adjust and just gone off on one jabing his little screwdriver through one of the coils....

I have an old txv so i think i'll put it under a bucket proped up with a stick to see if i can catch him

Jon

[coolhibby1875]

so where was the leak?

[Gingerair]

I thought all the leeks were in wales ???

[monkey spanners]

so where was the leak?

So far i have fixed a leak on the suction service valve, fixed a leak on n.1 txv outlet, then had to chop out n.1 evap as it lost 20bar over night, re connect the other two evaps, chopped out a 3/4" flare connector that had ptfe tape around the threads, when will people learn that flares don't seal on the threads....

Its all back together now with another 20bar so fingers crossed.

Keep a lookout for a mushroom cloud in the oxford, or possibly hungerford direction if Multi is correct, tomorrow morning....

[lowcool]

hydrostatic test on lines and gauges as a last resort.

[monkey spanners]

Its all up and running now! Thought one of the txvs had died after being pressure tested but then i remembered it was a mop valve.

But the leaks didn't stop all was going well till the farmer pointed out the water leak from around the milk outlet pipe....

Jon

[acb]

is it the ice builder part or the bulk tank you are having problems with if its the bulk tank, then the leak is probably in the internal pipework, ive had this before, crank up the nitrogen pressure and put your ear to the tank you should be able to hear it, then cut a hole in the side to pinpoint it and then weld, if its an icebuilder, good luck its probably sucked in water by now.

[coolstuf]

Did you take the temp of the pipework before and after pressure testing. Remember your pressure temp relationship.

[chemi-cool]

Jon,

From my experience with milk tanks, some time the leak is in the evaporator, under the outer cover.

The best way to eliminate this thought is to disconnect it from the cooling system , solder the suction pipe and pump it to 80psi with OFN.

If there is a leak, you will see it in minuets as the evaporator's volume is very Small

[multisync]

To be fair I think Monkey was monkeying around with us

(oh and I still maintain I was the closest: even if I was miles away..)

[monkey spanners]

Thanks for the replies, it was one of the evap coils which is just a 5/8" pipe that ice is formed on.
The tank had three seperate coils, and should have had a 3hp comp but came with a 2hp one (which matches the duty of the two remaining coils), so we decided to disconnect the leaking coil and put up with the longer run times.

Jon

[Old cooler]

have you tested the fusible plug?

[monkey spanners]

have you tested the fusible plug?

Yeah i checked it and the solder was ok, i even took it out and re sealed the threads to be sure.

Turned out to be a leaking evaporator in the tank which we disconnected, and ran the system on the remaining two evaps.

Jon

[Old cooler]

We used to get a lot of fusible plugs leaking, usually as they get a bit warm.


Steve

[monkey spanners]

We used to get a lot of fusible plugs leaking, usually as they get a bit warm.


Steve

Cheers Steve,

They seem to leak a lot round the threads too since the manufacturers switched to liquid thread sealer from ptfe tape, on copeland stuff if its ten plus years old its a given the threads will be leaking on them, i have taken to re sealing every one that i have recovered refrigerant from now to save work later on!

Jon