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Home pipe and fittings, entry by entry
Know Your Pipes is a reference of 52 entries on the pipe, fittings, joints and valves found in US houses: what each one is, how it is joined, what it is rated for and how to recognize it, with numbered sources on every entry.
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Featured entry
Lead pipe and lead service lines
A lead service line is the pipe connecting a water main to a building's plumbing when any part of that pipe is made of lead.
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) Copper pipe types K, L and M
- The chemical method behind PEX-A tubing was developed in 1968 by German inventor Thomas Engel, which is why it is called the Engel method. (source: Uponor) PEX-A pipe
- Solder that is not lead free may be put on the US market only if it carries a prominent label saying it is illegal to use in plumbing for drinking water. (source: U.S. Environmental Protection Agency) Lead-free solder
- Orangeburg sewer pipe often rots from the inside out, so a line can keep a round outer shape while its inner layers have already failed. (source: City of Ann Arbor) Orangeburg pipe
- One bonding clamp is enough for an entire yellow CSST system, but it may never be clamped onto the corrugated tubing itself. (source: International Code Council) CSST gas tubing
- A 1-1/4 in PVC drain pipe measures 1.660 in across the outside, well over the size in its name. (source: Charlotte Pipe and Foundry) Nominal pipe size, CTS and IPS
Categories
PEX and plastic supply pipe
Pipe that carries pressurized drinking water: PEX, CPVC, PP-R and polyethylene.
Metal pipe
Copper, galvanized and black steel, cast iron, CSST and lead.
Drain pipe and retired pipe
PVC and ABS drain pipe, plus the pipes people now replace: polybutylene, Kitec, Orangeburg.
Joining methods
How pipe ends are joined: push-fit, crimp, clamp, expansion, press, compression, solder, solvent weld, threads, fusion.
Fittings and valves
Shapes, transitions, dielectric unions, drain fittings and shutoff valves.
Sizes, codes and marks
Nominal sizes, sizing basics, NSF/ANSI marks, plumbing codes and the print line.
Choosing pipe and trouble
Identifying pipe, picking pipe for a job, freezing, sunlight, leaks and bursts.
Updated . Entries are written by the Know Your Pipes editors from codes, standards bodies, government agencies and pipe makers’ documents. How entries are written and who runs the site.