Any changes to what people are using for ammonia charging/transfer hoses?
Standard hydraulic, EPDM, PTFE, Parker 7262 ?
Cheers
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Any changes to what people are using for ammonia charging/transfer hoses?
Standard hydraulic, EPDM, PTFE, Parker 7262 ?
Cheers
seanf,Quote:
Originally Posted by seanf
Don’t know, but if has previously been okay, probably okay.
Hoses usually perforated so does not bubble.
EPDM okay with liquid ammonia, but does not like oil, so possibly avoid.
When you ask suppler for guarantee, that usually sorts them out.
We get hoses tested annually.
Cheers Ranger. Do you have a certain brand and type of hose your company uses?Quote:
Originally Posted by RANGER1
seanf, please check PM.
Cheers Ranger
We used to use hydraulic hoses, but they were heavy and would leak over time to form blisters on the outer skin.
That's when we learned we could get them perforated like ranger said :)
but it would still smell like ammonia around the hoses.
And you could get a nasty surprise when getting in the car in the morning.
Over time, with the consumption rate of hoses, it was cheaper to go for the expensive durable kind instead of the use and throw away.
The hydraulic hoses would have a life span of maybe 6 months with our use and then they'd be leaking so much it wasn't even cost effective to cut out the leaking parts and make shorter hoses.
The type we changed to is steel braided PTFE, same as we use on the plate freezers, they weigh less and and last longer. the set I have now I've had for over 3 years.
Cost is around £40 per meter though, but considering the lifespan I think it's worth it :)
Tycho,
Out of interest can you roll these up easily to fit in service vehicle?
Thought they may be at risk of kinking.
Looks like you can get smooth bore, but also smooth bore exturnally convoluted to help with hose kinks.
https://www.duncanrogers.com/hydraul...-overbraid/172
they are corrugated on the outside but smooth on the inside, and coil up like a dream as they don't have a "memory" like the rubber hydraulic hoses.Quote:
Originally Posted by RANGER1
I have a "charging hose" with ball valves on either end that I keep pressurized so I don't have to purge it or vacuum it before use.
pressurized, not like I leave it with 6 bar, after purging it I close the valves when there is still clean NH3 gas in it.
a coiled up 10-15 meter hose I can hold up with my arm outstretched.
Attachment 16342
They take being driven over by forklifts, maybe not repeatedly but a couple of times :)
The hydraulic hoses are also braided, and had one being driven over by a forklift and it was completely blocked, couldn't push 40 bar of N2 through it.
Seen as I haven't posted any videos in a while,
Here's me playing with a 15 meter hose :)
https://www.youtube.com/watch?v=43m3wTg6bHg
The supplier of this particular hose does a demonstration where he folds it in half and kinks it like a garden hose and keeps pulling till it's kinda straight again, and still no leaks, while it's not recommended, it holds up :)
In the years I have used this kind of hose... I know, I know I come across as a new born religious person, but when I see something that works, and I have field tested it and it actually works, and it's better than something we had before, and I am confident in the product to put my name on it when selling it to a client, until something better comes on the market, I'm selling this product :)
It's the same hose we use on plate freezers.
Back when, the plate freezer hoses were foldable, with a stainless steel inner and stainless steel braiding, like this:Attachment 16343
And that was the trade standard, stainless steel flexible inner core and stainless steel braiding.
Absolutely top shelf product... Costs a bit more than an identical hose made in non stainless steel, but we sold it in as "a lifetime investment" as in the stainless would last 20 years while the carbon steel would last maybe 5 years.
And we believed it, so we sold it, and the customers believed it so they bought it, and we believed it too..
We went on the ship and cut all their existing hoses in half with a grinder so we could get at the nuts with an "ugga dugga"/impact driver to quickly remove the old stuff.
Then we had to repack all the hose fittings between the aluminimum plate and hose, so those were removed by hand so as not to wreck the threads in the plate (we found out that using a "ugga dugga" would sometimes strip the threads in the aluminimum plate), then we cleaned the threads in the plate with a Thread tap, then we had a special air gun that blew backwards we'd stick in and blow all the crap in our faces instead of into the plate.
, fitted the fittings back in with, at the time Loctite 577 and activator (since for Loctite 577 to properly bond between stainless and other metals it needs activator) something we learned at the time. So for each for each nipple going back in, we had to apply 577 to the nipple, then the activator came in this tiny mosquito spray bottle and we had to *squeek squeek" two sprays on the nipple before we screwed it back into the freezing plate to ensure a proper sealing bond.
Then, at that time, the liquid hose and return hose were two different sizes, and we had two euro pallets each maybe 5 feet tall, filled with hoses hoisted down into the factory.
And on the old Kværner freezers the layout if I remember correctly was so that you could do return hoses first as they were from the top of the plate and to the top collector, and then you could do the liquid hoses as they were also from a top manifold, but outside the return hoses.
Anyways, that meant you had to work from one end to another, and then go back and do the same thing over again, and we fond that that was very detrimental to our wish to live :)
and the plate freezers, as all refrigeration equipment, though they are instrumental in the day to day operation of the ship, and should the freezing plant or equipment fail and the onboard technicians can not service it, the ship is going to port no question, and the onboard technicians are being to be blamed, but still, critical equipment like vertical plate freezers are pushed/placed as close to the bulkhead as possible to make space for processing equipment to a point where they are no longer serviceable in a normal way and technicians have to crawl under other equipment that may not accommodate the use of PPE in these times where ammonia is widely used.
Another digression :)
So we'd sit with our legs out under the plate freezers our backs towards the bulkhead, and our nose on the hoses.
One man, usually the most senior, would be on the front side handing us either a return hose or liquid hose, and when we were done with a freezer we'd be done and could come out, instead of having to go back to the beginning and do another row :)
Huge digression here,
But pretty much all of the Norwegian fishing fleet were sold on stainless steel hoses for the plate freezers.
Because they were tired of "grrrm having to replace a hose or two everytime they were in port" is costly and the cost of the loss of *****' grr grr
So they all went gradually over to stainless steel hoses.
What happened?
The amount of broken hoses went skyrocket, and claim orders came in from everywhere.
We'd have to give them new hoses on claim and some hours to change them, but it was killing us compared to the identical hoses, identical, but in carbon steel.
We'd claim our supplier and get free hoses, but we had to cover the hours for people to replace it.
Until some guy had the bright to take a defective hose and send it in for analysis.
So we did, and what they found was Chlorine, the ship used Chlorine to clean and sanitize the factory area, so they would spray everything in the factory with a strong Chlorine agent, let it work, then they would come back and spray everything with fresh water.
But the revisit with freshwater was'nt enough to remove all the Chlorine from under the braids on the stainless steel hoses, so the chlorine would stay there and eat away at the hose, causing pin prick leaks.
This is similar to the results we got from the laboratory:
https://www.penflex.com/chloride-chl...loy-selection/
But the pictures we got were with electron microscope, so we could see the Chlorine crystal resting on the side of the hole it had eaten in the stainless steel.
So as an FYI if you are delivering any refrigeration plants with stainless steel, make sure or inform your client that they should not use Chlorine or Cloride detergents in areas where stainless steel pipes are used.
https://inspectioneering.com/tag/chl...osion+cracking
After learning about the use of Chlorine and how it works on "stainless"
A few years later:
There was a case in my city in Norway, where the ventilation ducts in a public swimming hall fell down, during hours when there were people using the pool, luckily it landed on a support structure and nobody got hurt.
The ventilation ducts were hanging from the ceiling using something we in Norway call "patent reel"
This kind of thing:
Attachment 16344
My initial thought was that they had gone out and gotten "Stainless steel", because stainless steel is the best right? :)
There was a news article about it, and I commented on it saying that the contractor had used the wrong grade of "stainless" and the corrosive high humidity and chlorine rich environment had eaten through the supports they used, and I suggested other materials, then there was a supplier of this stuff that commented and said Tycho is right, the material they probably used is not for use in this environment, but instead of what Tycho is suggesting they should have used HCR steel that is more stress corrosion resistant than stainless steel.
Then there was a new article two days later where the newspaper had brought in a material specialist in metallurgy that explained that A3 and A4 stainless, while stainless aren't super metals and they are susceptible to corrosion in certain environments.
They had contacted the subcontractors that delivered the metal bands to the contractor and found the quality that they had sold to the contractor, and they had spoken to the contractor.
When it was published I was like "Hah! told you!
but then I started thinking... if I'd kept my mouth shut in the comment field, The guy that corrected me may never have posted to correct me.
And so this whole episode might have turned into a blame game and endless government investigation.
Another Digression
If you made it to here, reply with "556 I read it all before replying"
Tycho,
Thanks might check out.
Probably expensive, but the one we get are anyway.
Tell you what, pm me your address and I'll send you a 3 meter one :)Quote:
Originally Posted by RANGER1
we use the 1/2" hose, outside diameter, and we have 3/8 NPT female connection on either end
Because then I can fit male, female, valve or whatever directly on the hose,
The shorter hoses, 1 or 3 meter I have 10mm Ermeto on either end, female swivel nut on one end and male 10L on the other end, because then I can connect it to the plant with the Danfoss SNV 10mm we use and then I can splice it on to my other hoses using male to female if I need.
But the shorter 3 or 1 meter hoses are between the vacuum pump and the plant, so that is svivel 10mm ermeto on either end :)
I have a coil of 10mm Pneumatic pipe I can use as vacuum pump discharge, but most of the jobs are smaller and while it's not ideal, I leave the vacuum pump up on deck to vacuum through the 10-30 meter of hose, as I can leave it there to work while I take all the other tools back to the car and other wise clean up around the job. :)
Just read your “lengthy “ post, very interesting.Quote:
Originally Posted by Tycho
Stainless evaporative condensers could sufferer similar issues if not treated correctly.
Once again very interesting posts & stories.
Thanks Tycho, can you send one to saenf as well ��
Hi Tycho,
Do you know what brand and type the PTFE hose you use is?
Be interested to have a look at the details.
Cheers
If he pm me his address :) I can :)Quote:
Originally Posted by RANGER1
We purchase them from Hydroscand in Norway, link to the hose:Quote:
Originally Posted by seanf
https://www.hydroscand.no/hydropedia/slanger/1093-01
Yea"lengthy" when I am bored or have too much time on my hand, I'll write a dissertation :DQuote:
Originally Posted by RANGER1
Thanks Tycho.Quote:
Originally Posted by Tycho
I'll send you a message.Quote:
Originally Posted by Tycho
Love the posts Tycho, have worked on trawlers here but none on ammonia, found the same with stainless hoses on the 2 stage bitzers if we insulated them then they rotted, best to leave them open to air I found.
Yeah, back when Jackstone plate freezers were still popular, they had the same issue on the connections.Quote:
Originally Posted by al
They had a square flange with four 6mm bolts that held the part that had the hose connection to the plate.
I never understood their design because it was like they were thinking "Let's add 3 more points that can leak" :)
Attachment 16348
and between those square flanges they had a foam cushion of some rubbery material that reminded me of Armaflex.
This material was designed to keep moisture out, but what it did was trap the moisture inside and it would eat away at the flanges.
Another thing they did was to wrap the hose connections with this grease coated fabric that apparently works well on hydraulics on machines that are out in the weather.
However it did not work well on platefreezer hoses that get hot and cold, hot and cold.
it made the nut on the hose corrode to the point where it was paper thin and no longer hexagonal, but round. :)
The worst case of "If we clean it with Chlorine it will be super clean!" I have seen, was some poor ship owner in Norway that bought a factory trawler from Iceland to Norway.
The previous owner had been so kind as to "mothball" the factory and had sprayed it down with chlorine to prevent any bacteria forming.
Everything looked nice and pristine, but when I started looking at the 10 vertical plate freezers I noticed that there was dust on them and when I reached down between the plates to wipe it off I could feel pittings in the plate surface.
So before going any further, I pressure tested one of the freezers to 10 bar and sprayed the entire thing with soapy water.
Fine foam were formed on the side of every plate., with a blower underneath, I could have had a foam party :)
Sad for the owner that he had to scrap all the plate freezers