Bushing, Spigot x Socket PVC Schedule 40 4" x 1-1/4" (437-418)

The 437-418 is a Schedule 40 PVC reducing bushing with a 4-inch spigot (plain end) and a 1-1/4-inch socket (slip) outlet. The spigot end solvent cements directly into any standard 4" Schedule 40 or Schedule 80 PVC socket fitting, while the socket outlet accepts the outside diameter of standard 1-1/4" Schedule 40 or Schedule 80 PVC pipe via solvent cement — producing a fully cemented, permanent transition from a large-diameter pipeline to a mid-bore solvent-welded branch, lateral feed, or secondary circuit without introducing a threaded joint at the reduction point.

The 1-1/4" outlet size occupies a practical middle ground in the 437 series 4" inlet sub-series — larger than the minimal-bore taps served by the 437-415 (1/2") and 437-416 (3/4") and better suited to applications where the downstream branch must carry meaningful flow rather than serve a sensing or injection function alone. Typical uses include secondary supply circuits, zone feed headers, bypass lines, and equipment inlet connections where the full assembly must remain within a bonded solvent-welded system and a threaded transition is not desired. Where a 1-1/4" female threaded outlet is needed at the same 4" inlet, the 438-418 (Spigot x FPT, 4" x 1-1/4") is the corresponding alternative.

For the 4" spigot end, use an IPS-grade, heavy-bodied solvent cement and a medium-bodied PVC primer per ASTM D2564 — for 4" and larger joints, a two-coat application is recommended to ensure full socket penetration and a reliable, leak-free bond. The 1-1/4" socket outlet follows standard primer-and-cement procedure for small-diameter PVC joints; ensure full pipe insertion to the socket stop and maintain joint alignment during the cure set period.

Specifications:

Industries & Applications:

• Municipal & Commercial Plumbing — Reduces a 4" cemented main line socket to a 1-1/4" solvent-cemented branch for secondary supply circuits, zone feeds, or service connections in commercial plumbing systems where an all-bonded transition is specified.
• Water Treatment & Distribution — Provides a cemented mid-bore branch connection on large-diameter PVC distribution and treatment system pipelines for bypass lines, secondary treatment feeds, or flow diversion circuits within fully solvent-welded assemblies.
• Irrigation & Agricultural Systems — Used at pump discharge headers, filter manifolds, and mainline distribution points where a 4" cemented inlet must reduce to a 1-1/4" cemented outlet for lateral zone supply lines, pressure regulator feeds, or secondary circuit piping.
• Industrial Process Piping — Adapts large-diameter PVC process lines to 1-1/4" cemented branch connections for secondary process circuits, bypass loops, or equipment inlet feeds in fully solvent-welded corrosion-resistant systems where threaded branch joints are not specified.
• Pool & Spa Plumbing — Transitions 4" suction or return headers to 1-1/4" cemented branch connections for auxiliary circulation circuits, secondary equipment feeds, or zone supply lines in high-flow pool and spa systems.
• HVAC & Chilled Water Systems — Connects 4" PVC drainage or secondary piping to 1-1/4" cemented branch lines for drain circuits, condensate collection feeds, or secondary equipment connections on mechanical systems where an all-solvent assembly is preferred.