steam fittings

louie_2

what type of fittings are used in one pipe steam?cast iron or malleable iron?what class 150 or 300?thank you

Tony Conner

Cast Iron vs Malleable Iron

On residential steam systems, either cast or malleable are fine. Cast iron fittings have ratings of 125 and 250 PSIG, malleable iron fittings have ratings of 150 and 300 PSIG. With residential steam boiler safety valves lifting at 15 PSIG, any of these fittings are OK.

The only real advantage to cast iron fittings is that if you have trouble removing them, you can hit them with a hammer to break them. However, I've seen water hammer hit them, and break them by accident. I'm not a big fan of 125 cast iron.

louie_2

thank you very much for your helpful info..