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Grizzly
09-05-2010, 11:56 AM
I have a job coming up where I need some long hoses made up.
Not a problem. But whilst looking into what was required.
I realised that for us in the U.K. there is yet another RULE that we have to comply with.
Ammonia charging hoses should be "Tested and certificated Yearly".
Not that many I know, myself included have complied with this.
Anyway it transpires that I can get the hoses tested with either water or oil, for less than £30.00.
At that price it's easier to comply than possibly incur the wroth of some over-zealous Council type.
Usually fresh out of college with a bright shiny new "Book of rules".
The Hydraulic guys have asked me to specify what pressure I would like the hoses tested to?

I have specified 25 Bar which more than covers a condensing saturated pressure of 50c.
Which is the benchmark for all other refrigerants!

It is higher than any of the PRV'S on the Ammonia sites I work on.
Does anyone have an issue with this or can point me in the direction of where it is documented.
I cannot find it in EN 378.
Thanks Grizzly

josef
09-05-2010, 01:15 PM
Hi Grizzly, I use many years ZEC hose, and I have no problem, but perhaps is not very flexible, tough.
To my knowledge it is not specified in EN 378 criteria for monitoring each year.
http://www.zecspa.com/english/profilo-aziendale.aspx
http://www.zecspa.com/download/allegati/fn000287.pdf

Quality
09-05-2010, 02:01 PM
I have a job coming up where I need some long hoses made up.
Not a problem. But whilst looking into what was required.
I realised that for us in the U.K. there is yet another RULE that we have to comply with.
Ammonia charging hoses should be "Tested and certificated Yearly".
Not that many I know, myself included have complied with this.
Anyway it transpires that I can get the hoses tested with either water or oil, for less than £30.00.
At that price it's easier to comply than possibly incur the wroth of some over-zealous Council type.
Usually fresh out of college with a bright shiny new "Book of rules".
The Hydraulic guys have asked me to specify what pressure I would like the hoses tested to?

I have specified 25 Bar which more than covers a condensing saturated pressure of 50c.
Which is the benchmark for all other refrigerants!

It is higher than any of the PRV'S on the Ammonia sites I work on.
Does anyone have an issue with this or can point me in the direction of where it is documented.
I cannot find it in EN 378.
Thanks Grizzly

I can not help you with documentation as I do not think its mandatory but could be wrong ( I think its a recomendation)
But as for hoses call (01302) 746969

Hose Depot Direct

I can gaurantee they make the cheapest ammonia hoses in the UK Speak to Paul

Grizzly
09-05-2010, 10:11 PM
Thanks for the input Guys!
I have the hoses sorted and the re-tests of our existing.
Like many we can only use companies who are on our existing suppliers list.
Thanks for the options all the same.

My original questions still stands. "How does 25bar sound"?
And does anyone know where the testing of charging hoses is referred to?
As Josef mentions it does not appear to be listed in EN378.
Thanks Grizzly.

Tycho
10-05-2010, 09:40 PM
we use dual layer reinforced hydraulic hoses. they are rated for 250 bar and are durable for use with ammonia.

except if you leave liquid ammonia in the hose for a long time (overnight, 2-3 days), then it will eat microscopic holes in the inner layer and you get bubbles in the outer layer.


same kind of hoses they use for cranes on ships.


either way, any hose you use will get worn over time, especially the outer protective layer, and if a hose is damaged it will not pass inspection, so I would think it's cheaper to buy a new hose once a year and know that you have a good hose then to send a hose in for certification and have to add the cost of the certification to buying a new one anyways.


we have used the kind of hoses josef posted links too, but they are not very durable or flexible and tend to break apart much faster than the hydraulic hoses we use

josef
11-05-2010, 08:26 AM
Yes Tycho, cheaper to buy after the new year.:)

Bart Nabbe
17-05-2010, 11:25 PM
Hello Grizzly,

We in the netherlands use hoses with flexible stainles steel (anaconda woven ?)outside. Originally delivered with certificate. Lengths of 2, 5 and 10 meter for every engineer. We have them tested every year for ourselves but it is not listed in EN 378. We have them tested on 50 bar.
But in case of safety first for the engineers it's not overdone.

Same as with our oil pumps, they go up to 25 bar.

Good engineers are hard to get these days, hahahaha lol.

Greetz,

Bart.

Grizzly
18-05-2010, 05:28 AM
Good engineers are hard to get these days, hahahaha lol.


As they say over here.
"Many a true word spoken in Jest".

Sadly most above the level of Engineer seem to have forgotten!
Grizzly