When installing new water lines or replacing old piping in a home, one of the most common choices is black pipe. Black pipe refers to thin-walled steel pipe that has been hot-dip galvanized, giving it a matte black finish. This type of piping has been used for decades in residential plumbing applications. Below we look at key characteristics, benefits, proper installation techniques, and usage considerations when utilizing black pipe for water lines.
What is Black Pipe?
Black pipe used for water lines is usually galvanized steel pipe that conforms to ASTM A53 specifications. It has a zinc exterior coating applied to the base steel that protects against corrosion. Black pipe comes in diameter sizes ranging from 1⁄2″ to 2″ for typical residential uses. It is relatively thin, lightweight, and sold in threaded sections for easy joining. Black pipe fittings like elbows, tees and couplings are also threaded to allow creating piping runs.
Benefits of Using Black Pipe for Water Lines
Black steel pipe offers several benefits that make it well-suited for residential water line applications:
- Inexpensive compared to copper, PEX or CPVC piping
- Readily available at most hardware stores and home centers
- Strong yet can be easily cut and threaded in place
- Simple to install using standard pipe fitting tools
- Threaded connections seal tightly without leaking
- Long service life exceeding 50 years
- Withstands water pressures over 100 psi
- Suitable for hot and cold potable water delivery
- Can be painted after installation for aesthetics
Proper Installation Techniques
Correctly installing black pipe protects against leaks and delivers maximum service life:
- Measure runs and pre-assemble fittings and valves before mounting
- Use pipe hangers to securely fasten lines to joists and studs
- Ensure pipe threads are properly cut using quality dies
- Carefully thread pipe connections using thread seal tape
- Tighten joints firmly but not excessively to avoid cracking
- Route cold water lines on the north side of dwelling
- Insulate lines against freezing and sweating if passing through unconditioned areas
- Label valves and lines for easy identification and maintenance
Usage Considerations
Points to weigh when deciding on black pipe include:
- Requires skill and special tools to thread and assemble connections
- Joints can loosen over time and need occasional retightening
- Cold water condensation may lead to surface oxidation
- Can transmit noise and vibrations more than other piping
- Steel has higher thermal conductivity compared to plastics
- Needs painting or insulation for aesthetic finished appearance
For delivering pressurized water in residential settings, black steel pipe remains a viable, cost-effective choice. With proper installation and joint sealing, black pipe water lines can provide decades of reliable service.