Reducer Bushing, Spigot x FPT PVC Schedule 40 1" x 3/8" (438-129)

This 1" x 3/8" Schedule 40 PVC Reducer Bushing (Spigot x FPT) provides a compact mixed-connection transition from a 1" socket fitting hub down to a 3/8" female NPT-threaded outlet, consolidating a significant 2.67:1 diameter reduction and a socket-to-thread material transition into a single fitting body without the need for a separate inline reducer coupling, hex bushing, or multi-piece transition assembly. Constructed in white Schedule 40 PVC, it offers reliable performance in commercial plumbing, irrigation, and light industrial installations where a 3/8" male-threaded instrument fitting, pressure gauge connection, flow meter port, sensor component, or legacy small-bore service connection must be installed directly at a 1" socket assembly port location.

The 1" spigot (male plain end) is sized to insert directly into the hub of any standard 1" socket-end fitting — tee branch outlet, cross port, coupling end, elbow outlet, or valve body — and is solvent-cemented in place to form a permanent, leak-free joint at the outer face of the hub. The 3/8" FPT interior accepts any standard 3/8" male NPT-threaded fitting, instrument connection, pressure gauge, flow meter port, sensor fitting, or service component for a pressure-tight mechanical connection when made up with thread sealant or PTFE tape. The 3/8" FPT outlet is a less commonly specified NPT thread size than the industry-standard 1/4" instrument port or the widely specified 1/2" small-bore service connection — appearing in specific legacy instrument fittings, certain pressure gauges and flow meters with 3/8" NPT connections, and dedicated small-bore service components where the 3/8" thread size is specified by the downstream equipment or instrument manufacturer. This Spigot x FPT mixed-connection configuration is the correct choice when the upstream 1" assembly is an all-socket PVC system and the downstream component at the branch or port location is a 3/8" male-threaded fitting or device; it should not be confused with any 437 series all-slip counterpart at this size (Spigot x Slip, 1" x 3/8" if stocked), which provides a 3/8" socket outlet for a cemented pipe run rather than connecting a male-threaded component, with the 438-130 (1" x 1/2" Spigot x FPT if stocked), which serves the broader-demand 1/2" small-bore service connection application, or with any 439 series MPT x FPT hex bushing counterpart at this size, which threads into a 1" female-threaded port rather than cementing into a 1" socket hub.

Rated to approximately 450 psi at 73°F (governed by the 1" spigot end), this bushing is suited for standard commercial and light industrial water distribution and irrigation service within its pressure class. NSF/ANSI 61 listing confirms suitability for potable water contact.

Apply solvent cement to the spigot exterior and the interior of the receiving 1" socket hub per ASTM D2564 procedures, inserting fully and holding briefly for initial set. On the 3/8" FPT end, use PTFE tape — wrapping a minimum of two to three times in the thread direction — and confirm that the 3/8" male NPT threads of the mating component are started by hand and seated squarely before applying final torque; at 3/8", the shallow thread engagement depth makes cross-threading a more common installation error than at larger diameters. Avoid over-torquing — PVC threads require hand-tight plus one to two turns; at 3/8", the engagement range before overtorque risk is short. Allow adequate cure time on the cemented spigot joint before pressurizing the system, and derate pressure ratings for elevated temperatures per published derating curves.

Specifications:

Industries & Applications:

• Industrial Process Piping — Incorporates 3/8" male-threaded pressure gauge connections, flow meter ports, pressure transducer inlets, and legacy instrument fittings directly at 1" socket fitting hubs on process water distribution headers, chemical feed lines, and industrial fluid handling assemblies in water treatment, chemical processing, and manufacturing facilities where a downstream instrument or service component specifies a 3/8" NPT male connection at a 1" socket hub port location
• Irrigation & Water Distribution — Provides 3/8" male-threaded pressure monitoring connections, flow meter stubs, and small-bore instrument taps directly at 1" socket tee branches, cross ports, and manifold hubs in agricultural and municipal irrigation pump station assemblies where a 3/8" NPT-specified instrument or monitoring component must interface with a 1" all-socket mainline assembly port
• Chemical Process Piping — Delivers a corrosion-resistant mixed-connection socket-to-thread transition at 1" socket fitting hub ports in systems conveying acids, caustics, fertilizer solutions, and other chemically aggressive fluids where a 3/8" male-threaded instrument connection, legacy chemical injection stub, or small-bore service component must be incorporated at the socket fitting hub without metal adapter chains
• Commercial Plumbing — Provides a 3/8" male-threaded instrument stub, pressure gauge connection, or legacy service fitting access point directly at 1" socket fitting hub outlets in commercial building water distribution systems where a downstream component or equipment inlet specifies a 3/8" NPT male thread at a 1" socket assembly port
• Water Treatment & Aquaculture — Used at 1" socket tee branches, cross ports, and manifold hub outlets where 3/8" male-threaded instrument connections, flow meter ports, pressure monitoring components, and legacy service fittings must be incorporated directly at socket fitting hub locations with NSF/ANSI 61 compliance required throughout the assembly
• HVAC & Mechanical Systems — Transitions 1" socket fitting hub ports to 3/8" male-threaded instrument connections, legacy gauge taps, and small-bore service components on cooling tower supply headers, chilled water distribution manifolds, and chemically treated water system socket assemblies within the Schedule 40 pressure class where a downstream component specifies a 3/8" NPT male thread