Cap, FPT PVC Schedule 40 1-1/4" (448-012)

This 1-1/4" Schedule 40 PVC Threaded Cap (FPT) provides a clean, pressure-rated closure for any standard 1-1/4" male NPT-threaded pipe end, nipple, or fitting outlet in commercial and light industrial piping systems. Constructed in white Schedule 40 PVC, it offers the corrosion resistance and chemical compatibility required across a wide range of fluid handling applications where a 1-1/4" male-threaded port must be sealed reliably — whether for permanent closure, phased construction, pressure testing, or future system expansion — without the added cost or weight of a metal cap.

The single female pipe thread (FPT) interior is cut to NPT tapered thread standards, threading directly onto any 1-1/4" male NPT pipe end or nipple to form a pressure-tight mechanical closure when made up with thread sealant or PTFE tape. As a terminal fitting, the threaded cap is the standard solution for closing unused branch outlets at male-threaded nipple stubs, capping system test points between pressure tests, sealing spare ports on manifolds and valve bodies at male-threaded connections, and terminating dead-end threaded lines during phased system construction or expansion. The FPT cap threads over a male pipe end — it should not be confused with the slip cap (447 series), which sockets over a pipe end and is solvent-cemented in place for a permanent bond, the spigot plug (449 series, including 449-012 confirmed in this catalog session), which cements into a socket fitting hub rather than threading over a pipe end, or the MPT plug (450 series), which threads into a female port rather than over a male end. At 1-1/4", this cap is most commonly encountered closing out male-threaded nipple stubs on valve station assemblies, tee branch male-threaded outlet stubs, manifold spare ports, and system test points in irrigation distribution assemblies, commercial plumbing branch supply systems, and light industrial process water assemblies where 1-1/4" is a common intermediate distribution diameter. The threaded construction allows the cap to be removed and reinstalled without cutting into the assembly — a practical advantage over permanent solvent-cement closures wherever future port access is anticipated.

Rated to approximately 370 psi at 73°F, this cap is suited for standard commercial and light industrial water distribution and irrigation service within its pressure class. Its PVC composition provides excellent resistance to corrosion, scale, chlorinated water, and a broad range of chemical exposures — including resistance to seizing onto male threads over time, making it a more maintainable long-term closure than metal caps in moisture-prone or chemically active environments. NSF/ANSI 61 listing confirms suitability for potable water contact.

Install using a quality pipe thread sealant or PTFE tape on the male NPT threads before engagement. Avoid over-torquing — PVC threads require hand-tight plus one to two turns; excessive force can crack the fitting or distort thread engagement. If used as a temporary test cap, inspect the fitting and threads before returning to service. Derate pressure ratings for elevated temperatures per published derating curves.

Specifications:

Industries & Applications:

• Irrigation & Water Distribution — Seals unused or temporarily inactive 1-1/4" male NPT pipe ends, nipple stubs, and manifold outlet ports in agricultural and municipal irrigation systems, allowing future tap additions or system extensions without cutting into the distribution assembly; commonly used at valve station tee branch male-threaded stubs, manifold spare ports, and distribution header male-threaded terminations where future expansion is anticipated
• Commercial Plumbing — Caps 1-1/4" male NPT pipe ends and nipple stubs on pressurized supply systems, distribution manifolds, and branch supply assemblies in commercial building water systems during construction phasing, pressure testing, or permanent closure of unused male-threaded branch connections at the common intermediate 1-1/4" distribution diameter
• Industrial Process Piping — Closes unused branch outlets, spare manifold ports, and dead-end test points on 1-1/4" male-threaded process water headers and distribution assemblies in water treatment, chemical processing, and manufacturing facilities during construction, expansion, or commissioning phases where the cap provides both a pressure test closure and a reconfigurable future tap point
• Chemical Handling — Provides a corrosion-resistant threaded closure for unused 1-1/4" male-threaded ports on chemical distribution manifolds, pump station assemblies, and feed line headers conveying acids, caustics, fertilizer solutions, and other fluids incompatible with metal caps that may corrode, seize, or contaminate the system fluid over time
• Water Treatment & Aquaculture — Used to seal spare male-threaded ports on filter manifold stubs, pump station valve body outlets, and treatment equipment assemblies where NSF/ANSI 61 compliance and long-term chemical resistance are required at unused 1-1/4" male-threaded connection points throughout the system
• HVAC & Mechanical Systems — Caps unused 1-1/4" male-threaded ports on cooling tower supply valve assemblies, chilled water distribution manifold male-threaded stubs, and chemically treated water system equipment interfaces within the Schedule 40 pressure rating class