Reducer Coupling, Slip x Slip PVC Schedule 40 1" x 3/4" (429-131)

This 1" x 3/4" Schedule 40 PVC Reducer Coupling (Slip x Slip) provides a straight-through inline size reduction within all-socket PVC piping systems, accepting 1" PVC pipe at the larger socket end and 3/4" PVC pipe at the smaller socket end for permanent solvent-cement bonds at both joints — reducing the inline run from 1" to 3/4" at a single all-socket cemented joint without requiring a spigot bushing, threaded adapter, or multi-piece transition assembly at the step-down point. Constructed in white Schedule 40 PVC, it offers reliable performance across a wide range of commercial plumbing, irrigation, and light industrial applications where a 1" socket mainline or sub-main must step down to a 3/4" socket lateral, service line, or secondary distribution run inline without a direction change at the transition point.

The 1" slip socket end accepts 1" PVC pipe for a permanent solvent-cement bond on the upstream mainline run, while the 3/4" slip socket end accepts 3/4" PVC pipe for a permanent solvent-cement bond on the downstream reduced-diameter run, continuing the all-socket assembly at 3/4" from the reduction point. This Slip x Slip configuration is the all-socket approach to inline size reduction — the correct choice when the upstream 1" pipe run and the downstream 3/4" pipe run are both all-socket PVC and the transition must occur inline without a direction change, a threaded interface, or an intermediate fitting hub; distinct from the 437 series spigot x slip bushing (which reduces at a fitting hub socket rather than inline between two pipe ends), the 439-131 (1" x 3/4" MPT x FPT Hex Bushing), which reduces at a female-threaded port in an all-threaded assembly, and any reducing tee or reducing elbow in the 406 series, which combines the size reduction with a tee branch or direction change. At the 1" x 3/4" combination, this reducer coupling serves the most common adjacent-size step-down in residential and light commercial all-socket PVC irrigation grid and distribution assemblies — appearing wherever a 1" socket mainline or primary distribution header must supply a continuing 3/4" socket lateral, zone sub-main, or secondary distribution run without a fitting hub or direction change at the reduction point; in commercial plumbing branch supply assemblies where a 1" socket main steps down to a 3/4" dedicated fixture or equipment supply run inline; and in process water and light industrial socket assemblies where a 1" socket header transitions to a 3/4" socket service or instrument supply line at an inline step-down location.

Rated to approximately 450 psi at 73°F (governed by the 1" slip end), this coupling 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, making it a reliable long-term alternative to metal reducer couplings in moisture-prone or chemically active environments. NSF/ANSI 61 listing confirms suitability for potable water contact, including use in drinking water distribution and treatment systems.

Apply solvent cement to both the pipe end and fitting socket at each port per ASTM D2564 procedures, using a primer appropriate for the pipe and fitting schedule. Insert pipe fully into each socket and maintain a quarter-turn during assembly for even cement distribution across the joint surface. Note that the two socket ends are different sizes — confirm 1" pipe at the larger inlet end and 3/4" pipe at the smaller outlet end before cementing to avoid assembling the coupling in the incorrect orientation. Allow adequate cure time before pressurizing the system, and derate pressure ratings for elevated temperatures per published derating curves.

Specifications:

Industries & Applications:

• Irrigation & Water Distribution — Steps down 1" all-socket PVC mainline and primary distribution header runs to continuing 3/4" socket lateral, zone sub-main, and secondary distribution pipe runs at inline transition points in residential, light commercial, and agricultural irrigation systems where the 1" to 3/4" adjacent-size all-socket step-down is the most common inline reducer in residential and light commercial irrigation grid layout assemblies without requiring a fitting hub, direction change, or threaded interface at the reduction point
• Commercial Plumbing — Provides an inline all-socket size reduction from 1" to 3/4" at distribution branch supply transition points, service line step-downs, and equipment feed connections in commercial building water distribution systems where all-socket PVC construction is specified and the downstream 3/4" socket run must continue from the 1" main inline without a fitting hub or direction change at the reduction joint
• Irrigation Grid Assemblies — Serves as the standard inline step-down from 1" primary grid headers to 3/4" lateral distribution runs at grid layout reduction points in residential and light commercial irrigation manifold and grid header assemblies where the 1" to 3/4" socket reduction is the most frequently required adjacent-size step-down throughout the all-socket distribution layout
• Industrial Process Piping — Provides a permanent all-socket inline 1" to 3/4" size reduction at process water distribution header step-down points, instrument supply line transitions, and small-bore service line departures in water treatment, chemical processing, and manufacturing facilities where all-cemented Schedule 40 PVC construction is maintained at each inline size transition point throughout the distribution layout
• Chemical Handling — Delivers a corrosion-resistant permanent all-socket inline size reduction in systems conveying acids, caustics, fertilizer solutions, and other fluids incompatible with metal fittings, at 1" socket distribution header to 3/4" socket service line transition points where maintaining all-cemented socket construction throughout minimizes threaded joint count and leak risk at each inline size step-down
• Water Treatment & Aquaculture — Used at inline 1" to 3/4" all-socket size transition points on process water distribution runs, recirculating system pipe layouts, and treatment system distribution assemblies where NSF/ANSI 61 compliance and all-socket system integrity are required at every permanently cemented inline step-down point throughout the assembly