STZ Industries 4 in. FIP Black Malleable Iron Cap is a rugged, dependable sealing solution designed to cap off 4-inch pipe ends with precision and confidence. Built for demanding job sites, this cap combines durable materials with a practical finish to keep installations secure and looking professional.
Constructed from malleable iron and finished in a protective black coating, this cap delivers the strength you need to withstand everyday piping work while keeping a clean, job-ready appearance. The internal design is tailored for 4-inch connections, featuring female iron pipe (FIP) threading that mates with standard 4" male pipe ends for a reliable, leak-resistant seal.
- Internal 4 in. female threads (FIP) compatible with standard 4" male pipe ends
- Maximum working pressure up to 300 psi
- Maximum temperature rating up to 150°F
- Lead-free construction for safer, compliant plumbing and maintenance work
- Black finish provides a durable, professional look and additional protection on exposed installations
- Bagged packaging for organized storage and easy handling on-site
This cap is ideal for a range of real-world scenarios. Use it during new construction or renovations to safely seal off inactive lines, during pressure testing to prevent leaks, or in maintenance workflows to temporarily close off sections of a piping system. It’s particularly well-suited for commercial, industrial, and contractor projects where reliable, long-lasting caps are essential to keep systems secure while work is in progress.
Why choose this STZ Industries cap over other options? It combines robust malleable iron construction with a corrosion-resistant black finish and a lead-free composition, delivering a durable seal that can stand up to frequent handling and torch-free workflows on job sites. The 4-inch FIP sizing ensures a precise fit for compatible piping, reducing the risk of slip-off or improper sealing that can occur with cheaper, lower-grade caps.
Practical tips for installation and care: clean the mating threads before installation, use appropriate thread sealant or pipe joint compound rated for iron pipe, and tighten to a secure snug fit without overtightening. Store the cap in its bagged packaging when not in use to protect the finish and prevent scuffs that could affect threading or appearance on the next project.
With its blend of strength, safety, and straightforward, on-site practicality, this 4 in. FIP black malleable iron cap from STZ Industries is a reliable choice for sealing 4-inch pipe ends quickly and securely, helping you keep projects on track and piping systems correctly protected.
