Bushing, Spigot x FPT PVC Schedule 40 4" x 1/2" (438-415)

The 438-415 is a Schedule 40 PVC reducing bushing with a 4-inch spigot (plain end) and a 1/2-inch female pipe thread (FPT) opening. The spigot end solvent cements directly into any standard 4" Schedule 40 or Schedule 80 PVC socket, while the FPT bore accepts a 1/2" male-threaded fitting, valve, plug, or instrumentation connection. Representing the most aggressive size reduction in the 438 series, this bushing is the practical choice when a large-diameter pipeline requires a minimal-bore threaded tap for pressure sensing, chemical injection, air relief, or a small-bore drain port — all without adding inline adapters or interrupting the main run.

Built from rigid, high-impact PVC compound, the 438-415 is rated for continuous cold-water pressure service and is dimensionally compatible with ASTM D2466 Schedule 40 fittings throughout. The 4" spigot end requires 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 1/2" FPT port accepts PVC or metal male-threaded connections; apply PTFE thread tape or an approved pipe thread sealant on all threaded assemblies.

Specifications:

Industries & Applications:

• Municipal & Commercial Plumbing — Reduces a 4" main line socket to a 1/2" threaded port for pressure gauges, drain plugs, air relief valves, or small-bore service connections in commercial plumbing systems.
• Water Treatment & Distribution — Provides a minimal-bore threaded sample tap, chemical dosing port, or instrumentation connection on large-diameter PVC distribution pipelines where flow disruption must be minimized.
• Irrigation & Agricultural Systems — Used at pump discharge headers or filter housings where a 4" inlet reduces to a 1/2" threaded outlet for fertigation injectors, pressure transducers, or small solenoid valves.
• Industrial Process Piping — Adapts large-diameter PVC process lines to 1/2" threaded connections for pressure sensors, bypass bleed ports, or chemical injection fittings in corrosion-resistant installations.
• Pool & Spa Equipment Rooms — Transitions 4" suction or return headers to 1/2" threaded ports for air relief valves, pressure gauges, or small-bore auxiliary connections on filtration and circulation equipment.
• HVAC & Chilled Water Systems — Connects 4" PVC drainage or secondary piping to 1/2" threaded drain, vent, or condensate tie-ins on mechanical equipment and air handlers.