steel versus copper pipework

[xyon]

Hi,
I get the impression that copper pipe is preferred over steel for central heating systems. My question is, what is wrong with steel pipe, when the boiler, storage tank and radiators are all steel anyway?

 

[Fluffster]

Copper does not rust!
Pete

 

[doitall]

Steel is much stronger, but labour and material costs are considerably higher to install.

 

[Agile]

Do you still use steel boilers in NZ? ( As in cast iron? )

Tony

 

[xyon]

I can't really say much about commercial/industrial use in NZ, but most houses don't have central heating. I believe that welded steel or cast iron is still the go for wood (log and pellet) or coal water heaters here, what is the alternative. Gas is too expensive for central heating.

I had assumed possibly incorrectly, that installed steel pipe work would be less expensive than copper since the cost of copper pipe is 5 times steel.

I guess what I really want to know. Is the lifetime of steel pipe shorter than copper for a closed system with corrosion inhibitor?

Cheers
Bruce

 

[doitall]

No, steel will last just as long as copper and maybe longer in some environments.

NZ use a plastic tube with an aluminum barrier for most plumbing jobs afsaik

 

[xyon]

NZ use a plastic tube with an aluminum barrier for most plumbing jobs afsaik

Hi, PEX with aluminium is common for central heating. But for potable water Buteline (and a bit of copper) is used by 99% of plumbers, though that may be slowly changing as other system are on the market now.

 

[Jackrae]

Cast iron and steel are not the same material and have very different properties when it comes to corrosion due to oxidation. Steel is technically OK to use as a water carrier provided suitable and adequate chemicals are added to the fluid to prevent corrosion.

Here in the UK we use steel radiators and where no corrosion inhibitor has been used in the system, a black oxide gunge ensues.

Copper is technically superior to steel not only on the basis of corrosion resistance but it is also very much easier to instal. It accepts compression seal rings with simple hand tools, can be soldered with low temperature solders, can be readily bent and its surface is of a high enough finish to permit the use of simple o-ring fluid seal.

 

[doitall]

Sorry Jackrae but your argument is flawed from the start.

Steel is the preferred material in a lot of jobs, but agreed it is considerably more labour costly.

Steel tube, radiators etc will not corrode if the system is installed correctly and is sound. It does not need an inhibitor provided there are no leaks and fresh water isn't continually added.

Black oxide gunge is a product of air getting into the system and is an equal problem whatever materials are used.

Copper is better for domestic water, with heating it makes no difference other than 99/100 plumbers couldn't do an half descent job if they tried let alone with steel tube.

Who wants to use cheap and nasty push fit DIY fittings in a quality install, I certainly didn't, and I have no doubt I'd have been told to rip it out if I had.

The trouble as I see it, all the skill has gone from the trade, and at the same time any pride in ones work.

There's a few good guys on DIYnot who are quite happy to show off their work, it puts the rest of you to shame.

 

[Jackrae]

as you please - it was only an opinion not a thesis

 

[BigSnoopy01]

poor system design is the main cause of corrosion in any system. The bigest problem with steel over copper is installtion labour.