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monkey spanners
21-08-2010, 10:26 AM
Had a call to a new customer, 5hr 250 mile round trip, they were unimpressed with their local guy so i got recommended to them.

The main problem was the wash system on the milk tank, these new ones need a wash program writing for them on a laptop if the default wash is not working out.
It depends on the size of tank, 15,000L in this case and the water pressure etc how long fill times for the hot and cold water need to be etc.
Spent three hours messing about getting it to work ok, and then they wanted a check over the fridge systems while i was there....

Now i've seen bad brazing before, i've even been guilty of some if truth be told but i have never seen so many bad joints in such a short piece of pipe :rolleyes:
Thirteen joints in elbows and a tee as the suction lines exited the tank at the top, acces to this was from below 8ft up in the air with a gap 1ft wide between the tank and the plate heat ex and milk lines.
All the brazing was full of bubbles/holes, one leaked so bad the leak spray wouldn't stay in it! i brazed over it all with some 15% rods and it turned out much better than i thought.
Then i noticed another joint 9" up the suction line didn't look too clever either, on closer inspection the system had originally been installed using plumbing solder :eek: and all the heat i had put in had melted this joint too....

The phials on the txv's were clamped over the fittings, i could poke a screwdriver between them and the pipe...

After talking to the customer it turns out the original installers were lawn mower repair men, you couldn't make this stuff up :D

Eleven hours on site, 10kg R22, other bits and pieces, be lucky to get any change out of a grand, moslty due to the poor work of the original installers.

I'm doubtfull the new drop ins will be compatable with plumbing solder based on experience with R134a in the past so i think they will need to budget for new pipe work in the near future.

Now finally to the question, is plumbing solder even legal for refrigeration service?

Jon :)

Grizzly
21-08-2010, 10:49 AM
Hi Jon.
Amazing post as usual!
It sound like technology has reached even Milk parlours now?

I had heard that they were slightly more state of the art nowadays!
Anyway I haven't time to check at the moment. (But I will!)
I suspect either EN378 or The Pressure vessel Regs should cover brazed joints somewhere.
(Where is our Legal Eagle Abe? Nowadays?)
Cheers once again for the informative post.
Grizzly

Quality
21-08-2010, 11:37 AM
I seem to recall that halocarbon refrigerants such as R134A are not compatible with tin/lead solder.
But its common sense as you know not to use it.
I will dig out my info and post the it ,as I have got it somewhere.

Ps 250 mile drive and 11 hours that's what you call working for a living- what a star man
:)

chemi-cool
21-08-2010, 12:08 PM
Hi Jon,
As we do exactly the same service, its like looking at mirror, can you take some photos?

paul_h
21-08-2010, 02:27 PM
Are you talking about the tin/lead soft solder or the 2% 'yellow tip' rods that plumbers use for brazing (instead of the 15% 'brown tip' that we use)
I've never ever seen tin/lead soft solder used in any system.

monkey spanners
21-08-2010, 05:47 PM
Thanks for the comments guys,

Chemi, i'll take some pictures next time i go there, i nearly took a video with my phone but it was one of those when there was so much to do i just wanted to get on with it!

Heres some vids from other farms i've installed/service,

http://www.youtube.com/watch?v=hP0jnXT5SZI

http://www.youtube.com/watch?v=Ipg1FvUI2-c&feature=related

http://www.youtube.com/watch?v=v_w4NpE21ME


Paul, yeah normal lead/tin solder!, they have used it on the discharge valve too as i could easily scratch it with a screwdriver.

Not sure plumbers here use 2%, its either lead/tin or lead free for dinking water, but most likely it'll be plastic pipe now as its all they seem to fit!

For general pipe jointing i use rothenberger rolot s2 which is 2% are these the 'yellow tip' ones you asked about?, for driers and sightglasses johnson mathey 5%, for txv's 15%, and for dissimilar metals i have some 38% either flux coated or some i dip in a pot of flux.

Jon :)

paul_h
22-08-2010, 04:55 AM
OK, I've pretty much only use 2 types, 15% for cu-cu, and 45% with flux for cu-brass, cu-steel etc.
It's the way I was taught at school, and what every company I have worked for has done too.

Peter_1
22-08-2010, 08:30 AM
Soft soldering in Europe not allowed

EN378/2000 - 6.2.2.2.

6.2.2.2 Soldering
Soft soldering shall not be used for piping joints, the assembly of piping and where fittings are to be incorporated in
the piping.
NOTE: For such situations brazing or welding is preferable.

6.2.2.3 Welding
Welding shall comply with the appropriate European standards. When selecting the welding process, operating
temperatures, materials to be jointed and composition of filler metal shall be considered.
Fittings for butt welding shall be compatible with the piping material.
Coated (e.g. galvanized) pipes shall not be welded, unless all coating has been completely removed from the joint
area. Welded joints shall be suitably protected.
Welders shall be in possession of a valid approval certificate for the work in accordance with EN 287-1.

6.2.2.4 Brazing
The compatibility of all materials including filler and flux with the refrigerant shall be thoroughly established by
investigation. The possibility of corrosion shall be taken into account.
Brazing shall not be used for ammonia piping, unless the material has been proved to be compatible.
Brazing shall only be carried out by persons competent in this field.
NOTE: Other non-detachable joints can be used considering that their suitability has been proved.

monkey spanners
22-08-2010, 04:51 PM
Paul, i think i'll try and get some 45% ones to see if they are better than the 38% ones wolseley group sell :)

Peter, thankyou for the information, i'll let the customer know that their system has incorrect jointing materials used in it.
Is it actually illegal or just not allowed but nobody official does anything about it?

Jon :)

Peter_1
22-08-2010, 05:12 PM
Jon,

It's forbidden according to EU directives where the UK has translated this to their own British standards.
So, you have a written paper to show your client that the joints were made against the present law.

But who will punish the initial installer? For that, you have to go to court or make an agreement with this installer (paying the cost to do it the proper pay)

A good lesson for your customer: always work with qualified peoples who works according to proper/good craftsman rules.

It's like driving too fast: if nobody complains or you're not catch, you can drive as fast as you like.
Don't forget that you may not touch the work of someone else, otherwise you're loosing liability.

Quality
22-08-2010, 05:15 PM
The standard quoted is only that a standard not a regulation although BS EN 378 2008 has replaced the the 2000 publication but the posted material is just the same.

BS 7671 (17th edition regs) is only a standard but is used to enforce the law when things go wrong so ,as you already said if nobody does any thing about it.

who is gonna care

The Pressure equipment directive is a regulation in force in Europe which basically states the same information about compatibility.

Peter_1
22-08-2010, 05:31 PM
There are some small differences between the 2000 and 2008 version.

Quality
22-08-2010, 05:46 PM
There is a large amount of change between 2000 and 2008 but I suppose its how you read it and which part.
I was referring to the information you posted which virtually unchanged