Threaded black iron pipe fittings are commonly used in fire protection systems to join pipes made from black steel. They are made from malleable or ductile cast iron and feature tapered pipe threads that form a mechanical connection.
Pipe fittings threaded black iron
These fittings include:
- Elbows – Available in 90 degree, 45 degree and other angles
- Tees – Used for branches or changes of direction
- Couplings – Connect pipes of similar or different sizes
- Bushings – Transition between different pipe sizes
- Unions – Allow pipes to be joined and separated
Threaded black iron pipe fittings feature:
- Integral threads that match the pipe threads
- Zinc plating for corrosion resistance
- Pressure ratings up to 300 psi
- Available in Schedule 40 and 80 based on required pressure
For fire protection systems, threaded black iron pipe fittings must:
- Comply with NFPA 13 standards when the fittings exported from pipes and fittings companies
- Be listed or approved for fire protection use
- Have a minimum pressure rating of 175 psi
- Use only approved thread sealants
Fire protection pipe fittings
In addition to black iron fittings, fire protection systems use fittings made from:
- Galvanized steel
- Ductile iron
- Grooved-end fittings with mechanical joints
- Push-fit fittings
The type of fitting used depends on factors like:
- Fluid pressures
- System requirements
- Cost
- Longevity needs
- Installer preference
All pipe fittings used in fire protection systems must meet the material, pressure, sealant and installation requirements of NFPA 13 to ensure they perform reliably in the event of a fire. Threaded black iron fittings from pipes and fittings companies, remain a common choice due to their affordability and availability.