Radiator Valves for 1-pipe steam - Brass or Bronze?

Riverton_1895

I'm replacing some steam radiator angle valves and gate (straight) valves in an old one-pipe steam system. It appears that I have a choice between brass or bronze in different weights from a variety of manufacturers. The sizes I need vary - 3/4", 1" and 1-1/4". I've read up on the differences between brass and bronze, but still have no idea which is the better choice for a steam radiator valve. Help?

Jamie Hall

If I had the budget I'd go for bronze... that said, radiator valves have a gotcha: they are matched to the spud in the radiator itself. Once in a while you get lucky and can just replace one or the other, but usually the union faces don't match and leak. So you're best off to replace both.

Second thought: are you sure they are gate valves? Not common for radiators, though one does see them (sometimes) on mains, which they can cause all kinds of problems. If they are on mains, replace them with full port ball valves instead and you'll be a lot happier.

Third thought: are you sure you need to replace them and not just repair them? Repair is a lot easier and cheaper...

Riverton_1895

Thanks Jamie. Is there a reason why bronze is better? I called a valve manufacturer and their tech. rep. told me the specs/performance for their bronze and brass valves are exactly the same. He said he's been doing this for 30 years and has never been asked that question. He also suggested I use whichever costs less. But, I'm pretty sure he's not a steam heat expert, so...

My understanding is that brass is typically more malleable than bronze, whereas bronze is harder, but also more brittle. I'm just not sure I understand why one or the other is better in this case.

I think I also read that bronze valves are always cast whereas brass valves can be manufactured in a variety of different ways. That might make some brass valves cheaper to manufacture, but I'm pretty sure all of these valves are cast.

Further, it seems like the composition of these alloys can vary - i.e., both bronze (copper and tin) and brass (copper and zinc) may have lead and other metals added to make the metal more workable or to give it specific properties. For applications in which the valve would come in contact with potable water, lead-free would be important, but it seems like lead is sometimes used in both alloys. I did see some brass valves that were marketed as lead-free.

It may not matter either way, but it seems like it might.

Jamie Hall

The fact of the matter is that a quality valve of either metal will be fine. A cheap valve of either metal will be just that -- cheap.

Riverton_1895

Okay - thanks! I agree. I had asked my HVAC contractor what valves they typically use and he told me they buy whatever is available. Over the last century, I think that has also meant using bushings to change the pipe sizes to accommodate valves that were salvaged from elsewhere or happened to be in stock locally. I'm replacing about 6 of these valves for a variety of different reasons and acquiring the right sizes and shapes would likely require that my contractor drive around to a few local supply houses so I decided to order them in advance. That's what drew me into the bronze vs. brass conundrum. I'm looking for something that will last for the rest of my life in the house. I've seen Matco-Norca, Watts, ProFlo, B&K, Durst, Legend... Any brand recommendations?

Steamer1928

I've had to do this with two radiators in my house. For me it was a complete pain in the wazoo. The valves in my house are almost a century old, painted over multiple times, and generally did not want to budge. I ordered new ones from supplyhouse.com...they seem to have a good selection and ship pretty fast. Local supply houses were outrageously overpriced, perhaps because I am not a contractor. Bluefin and Matco were the two brands. Seem to be good quality.

Riverton_1895

I'm not positive of this, but it seems like the primary concern with brass (vs. bronze), to the extent that there is one, is dezincification. Although dezincification doesn't appear to be a major concern for a steam system, it could be an issue in areas where the water has a higher salt content. There are also dezincification resistant brass fittings available for some applications.

Fred

Don't overthink this. Brass or Bronze valves both are fine for a steam system. I'm willing to bet, if you go through your system, you'll find some brass fittings that date back to the original installation of the system. Also, look at the fittings on you Pressuretrol, the Pigtail it is mounted on, the fittings on other controls, they are typically brass. Bronze costs more but the added value is probably zero, unless you like the look better.