Old Red Brass Piping Systems

[kenejr]

In many old buildings still standing today, red brass was the material of choice for water distribution. Why isn't red brass considered for use today in a similar context (except for cost reasons). What are some of the problems with reuse of these piping systems that are 60-75 years old? Is red brass today manufactured differently than it was 60-75 years ago (for use as pipe)?

 

[Goorah]

Kenejr: I think you were on the right track when you mentioned cost. Have you ever priced a 10ft length of 3" OD brass vs thermoplastic? The one is a small fortune, the other "peenies" per foot by comparison! In today's competitive construction market, that's not a small factor.

Then there are other things to consider, which also boil down to cost: thermoplastic piping is lighter, easire (quicker) to work with, more "forgiving". In some ways it is the better choice compared to metal piping: My 1972 ASHRAE handbok states: "Contrary to the procedure with some metal pipes, no allowance need be made wth thermoplastic pipes for corrosion and consequent lowering of capacity with age. Field experience in USA and Europe indicate that capacity of plastic pipe after 30 years remains essentially the same as at the time of installation."

They're talking rigid platic pipe. I was at a jobsite today on an HVAC matter and was "appalled" to see that the plumbers were installing plastic tubing for supply and drain lines up to about 2" OD. It's approved and it's FAST: just run the pipes like wires. Special compression fittings at terminations and lines terminate to the user space in junction box like affairs. No elbows contend with. Yes, methods change with the time!

Not sure this would be allowed on a 20 story high rise.

 

[Goorah]

What do you mean by "re use"? Is the building being renovated?

 

[kenejr]

By the term "re-use", I mean that an existing infrastructure is in place (risers and distribution piping for domestic hot/cold water). A major infrastructure upgrade procedure is underway, and this item has been identified as somthing to consider replacing.

Over time, as repairs have been made, copper tubing was used. Presumably, older copper repairs used a high lead content solder. I've also read that some red brasses have had a nominal of 5% lead (and up to 15% lead).

Corrosion tendancies that I've been trying to research include hydrogen embrittlement and de-zincification of red brasses with high zinc content. There are also numerous "buried" galvanized steel plugs, several of which have already failed due to galvanic corrosion, causing extensive, sensitive damage. A program to replace these plugs is underway, but no documentation exists to identify possible locations, therefore they are accidents waiting to happen.

I am particularly apprehensive to reuse the existing red brass system because of the historic landmark status of the building, and a failure of this system may cause catastrophic damage to the historic fabric of the building. Replacement in kind with a more modern, stable and proven distribution system would be the recommendation I am leaning towards.

 

[Goorah]

Your logic for replacement seems wise. Now write a rcommendation with the potential hazards/costs outlined so the decision makers will be aware of the risks and to cover your own professional liability.