Bushing, Spigot x FPT PVC Schedule 40 4" x 1-1/2" (438-419)

The 438-419 is a Schedule 40 PVC reducing bushing with a 4-inch spigot (plain end) and a 1-1/2-inch female pipe thread (FPT) opening. The spigot end is solvent cemented directly into any standard 4" Schedule 40 or Schedule 80 PVC socket, while the FPT bore accepts a 1-1/2" male-threaded fitting, valve, or instrument connection. This configuration is commonly used when a large-diameter piping run needs to transition down to a smaller threaded branch, service port, or instrumentation tap without adding a separate tee or threaded adapter upstream.

Manufactured from rigid, high-impact PVC compound, this bushing is rated for continuous service in cold-water pressure systems and is compatible with standard ASTM D2466 Schedule 40 fittings throughout. The 4" spigot end requires an IPS-grade, heavy-bodied solvent cement and a medium-bodied PVC primer in accordance with ASTM D2564 — for 4" and larger joints, two-coat application is recommended to ensure full socket penetration and a leak-free bond. The threaded FPT port is compatible with PVC or metal male-threaded connections; use PTFE thread tape or an approved thread sealant on all threaded assemblies.

Specifications:

Industries & Applications:

• Municipal & Commercial Plumbing — Reduces a 4" main line socket to a 1-1/2" threaded service connection for valves, gauges, or branch takeoffs.
• Water Treatment & Distribution — Provides a threaded instrument or sample port on large-diameter PVC pipelines without breaking into the main run.
• Irrigation & Agricultural Systems — Used at pump discharge assemblies or filter headers where a large inlet reduces to a smaller threaded outlet for zone piping.
• Industrial Process Piping — Adapts 4" PVC process lines to smaller-threaded chemical feed, injection, or monitoring connections in corrosion-resistant systems.
• Pool & Spa Equipment Rooms — Transitions large-diameter suction or return headers down to smaller threaded ports on pumps, filters, or bypass assemblies.
• HVAC & Chilled Water Systems — Connects 4" PVC drainage or secondary piping to 1-1/2" threaded drain or vent connections on air handlers and cooling equipment.