What kind of tubes to use???

[Sanel]

Hello,

I would like your opinion about this subject, based on experience. It is very well known that the most often used tubes are copper tubes in refrigeration. Inovation on this subject are relatively old. What I mean by inovation? For example, when constructing multipak (two or more compressors) many companys use seamless tube or rostfrai tubes in specific sections of multipak. On suction side, back from evaporators to compressors is so called receptacle tube which one of the dutys is to prevent liquid blows on compressors which can damage it. Becouse of high pressures and gas velocitys copper tubes are not suitable, specially when we have multipak with bigger kW power. My question is ...which kind of tubs do you prefer, why and where do you use it? Is there any kind of researches done in this area? Is it possible to get any kind of dokumentation?

I hope my question is understandable!

You can send me dokumentation, research facts, ascertainments if you have any on following e-mail: sanelekic2003@yahoo.com

Thanks
Sanel

[Brian_UK]

On suction side,........Because of high pressures and gas velocitys copper tubes are not suitable, specially when we have multipak with bigger kW power. Hi Sanel and welcome to the forum.

With the exception of NH3 why do you say that copper tube is unsuitable for refrigerant usage?

[absrbrtek]

Sounds like a design issue rather than a tube issue. Copper is used all the time in hvac applications. Never heard of recepticle tube, sounds like you need eliminaters to prevent the refrigerant from carrying over.

[Sanel]

Hello,

I did not use the proper word. Of course copper tubes are used in refrigeration system. Hmmm, some times it is not easy to explain in english if it is not your mother language. Actually I spoke to several people who are working with biger systems 400kW+! Their answer was ...we mainly use rostfrai tubes in industry cooling systems. We use 80% rostfrai 20% copper. When I ask them why, they told me becouse copper tubes are much more flexible then rostfrai. When compressors strarts there are much much biger vibration compare to small systems. That's why if we use normal copper refrigerant tubes demages are possible especialy at points which are weld. So if you have a few hundred kg of gas in system and few tons of goods in refrigerating chamber it is not good for customer and not good for the company. They also use it for ammoniac systems.
So you can say it is mainly becouse of security reasons. Of course assembling is more difficult and it takes more time.
About this other cind of tubs which I mention it and named it "seamless tube" I did not find proper word in english. I will try to explain it in other words. Here in Slovenia we named them "črne brezšivne cevi" ...literally translation is "black seamles tubes"...not logic? Which mean they are made from iron in one piece (not weld) and polished from inside. That cind of tubes can also be used in industry refrigerant systems.

So where to use this cind of tubes?
- creamerys
- big central storehouse (refrigerating chambers,cold-storage chambers)
.
.
.

I have some nice pictures of rostfrai evaporator which we manufacture. Project from last year. It was for creamery in Croatia. It cools water in water tank (cca. 30m3) to 1 degree celsius. It is for pasteurization purposes. This got nothing to do with tube subject I open it on this forum. If you are interested I can send you pictures by e-mail so you can see it!

So, I hope I explain it more understandable?
What is your opinion on subject?

Thanks
Sanel

P.S. Hapy new year to all!!!

[US Iceman]

Hi Sanel,

It sounds like you are describing what we would call here in the US a carbon steel seamless pipe. ANother form of this is what we call ERW, which stands for Electrically Resistance Welded. ERW pipe has a weld seam along the length of the tube.

Seamless pipe is stronger than ERW pipe, but both can be used depending on the application.

Indeed, it is common to find this type of piping used in industrial refrigeration systems. I have also seen carbon steel pipe used for other refrigeration systems for the reasons you mentioned. Carbon steel pipe does offer some additional resistance to vibration, support, etc.

Whereas, copper is more suceptible to damage in larger systems.

Can you give me a definition for "rostfrai" please?

[Josip]

Hi, Sanel :)

Welcome to RE


Hello,

I did not use the proper word. Of course copper tubes are used in refrigeration system. Hmmm, some times it is not easy to explain in english if it is not your mother language. Actually I spoke to several people who are working with biger systems 400kW+! Their answer was ...we mainly use rostfrai tubes in industry cooling systems. We use 80% rostfrai 20% copper. When I ask them why, they told me becouse copper tubes are much more flexible then rostfrai. When compressors strarts there are much much biger vibration compare to small systems. That's why if we use normal copper refrigerant tubes demages are possible especialy at points which are weld. So if you have a few hundred kg of gas in system and few tons of goods in refrigerating chamber it is not good for customer and not good for the company. They also use it for ammoniac systems.
So you can say it is mainly becouse of security reasons. Of course assembling is more difficult and it takes more time.
About this other cind of tubs which I mention it and named it "seamless tube" I did not find proper word in english. I will try to explain it in other words. Here in Slovenia we named them "črne brezšivne cevi" ...literally translation is "black seamles tubes"...not logic? Which mean they are made from iron in one piece (not weld) and polished from inside. That cind of tubes can also be used in industry refrigerant systems.

So where to use this cind of tubes?
- creamerys
- big central storehouse (refrigerating chambers,cold-storage chambers)
.
.
.

I have some nice pictures of rostfrai evaporator which we manufacture. Project from last year. It was for creamery in Croatia. It cools water in water tank (cca. 30m3) to 1 degree celsius. It is for pasteurization purposes. This got nothing to do with tube subject I open it on this forum. If you are interested I can send you pictures by e-mail so you can see it!

So, I hope I explain it more understandable?
What is your opinion on subject?

Thanks
Sanel

P.S. Hapy new year to all!!!



What kind of pipes to use for refrigeration mostly depend on refrigerant used and then on the size and utility of the plant. Sometimes not in that order;)

For small to medium ***** systems you can use copper pipes.

For medium to small industrial ***** systems the best way is to use copper and stainless (rostfrei) pipes.

For big industrial plants both ***** and ammonia the best way is to use seamless carbon steel pipes SCH 40. BTW they are not polished from inside and usually we have to clean them before installation.

Amount of welding residues depend on welding system used.

For ammonia plants you can use either stainless steel or seamless carbon steel pipes.


ANother form of this is what we call ERW, which stands for Electrically Resistance Welded. ERW pipe has a weld seam along the length of the tube.

Yes, you can also use this type of pipes (I do not like them because I had too many leaks in ammonia systems;) but that was centuries ago, hope they improve that kind of welding today:D Mainly we use them for secondary refrigerants like water, glycol water...

For secondary refrigerants (water types=glycol water, calcium chloride...) you can use any of mentioned pipe or even plastic pipes.

To make a safety plant (due to stress, extension due to temp changes) with any refrigerant, very important is to install enough and right placed pipe supports, static or movable (especially with plastic PE pipes). This can be a problem sometime, to save some money installation companies are ready to reduce quantity and quality of supports :eek: (all pipes have to be installed;) ) what is not visible immediately, but tomorrow when is too late, leaving only a bitter taste in your mouth if you are a customer:mad:

Hope this will help a little;)

Best regards, Josip :)

[Paulajayne]

Educated guess :-

rostfrai = rust free / stainless steel.

Paula

[Sanel]

Educated guess :-

rostfrai = rust free / stainless steel.

Paula

Correct

regards
Sanel