Metal pipe
Category · 8 entries · Updated
Metal pipe in American houses ranges from copper water tube, the most common supply pipe for much of the twentieth century, to galvanized steel in older homes, cast iron drains, black steel and corrugated stainless tubing for gas, and the lead service lines water systems are now replacing.
Entries in this category
Copper pipe types K, L and MThe three wall grades of copper water tube under ASTM B88, how to tell them apart and where each is normally used.
Copper DWV pipeHard copper drainage tube made to ASTM B306 for drain, waste and vent lines, identified by a yellow print line.
Galvanized steel pipeZinc-coated steel water pipe found in older homes; it corrodes from the inside and can hold lead from upstream sources.
Cast iron drain pipeGray iron soil pipe for drain, waste, vent and sewer lines, made in hub-and-spigot and hubless (no-hub) forms.
Black steel gas pipeThreaded Schedule 40 steel pipe with a dark finish, long used for natural gas and propane piping inside buildings.
CSST gas tubingFlexible jacketed stainless steel gas tubing; yellow CSST must be bonded to the electrical grounding system against lightning damage.
Lead pipe and lead service linesSoft gray lead water pipe, mostly in service lines; how to recognize it and what EPA's 2024 rule requires of water systems.
Brass fittings and dezincificationBrass is a copper-zinc alloy used for valves and fittings; dezincification is corrosion that removes its zinc.
Did you know
- Type M copper is sold only as hard straight lengths, while types K and L also come as soft coils up to 100 ft long. (source: Cerro Flow Products) Read the entry
- Copper tube makers publish pressure ratings for annealed tube because the heat of soldering softens hard tube near each joint. (source: Mueller Streamline Co.) Read the entry
- Copper drainage tube made to ASTM B306 is sold only in the hard temper, never in soft coils. (source: Cerro Flow Products) Read the entry