Reducer Bushing, Spigot x FPT PVC Schedule 40 5" x 4" (438-490)

The 438-490 is a 5" x 4" PVC Schedule 40 reducer bushing in a spigot x FPT (spigot x female pipe thread) configuration. The spigot end inserts into a standard 5" socket fitting for solvent welding, while the 4" female-threaded port receives any compatible 4" male-threaded fitting, valve, or pipe end — reducing the connection from a 5" socket assembly down to a 4" threaded outlet in a single fitting body.

At 5" x 4", this is a large-diameter reducer bushing, and its application set reflects that. Fittings of this size are most commonly found in major municipal distribution systems, large-scale commercial irrigation infrastructure, industrial process headers, and high-volume pump station piping where large-bore PVC mains need to transition to a slightly smaller threaded connection point without adding an intermediate reducer fitting or a separate threaded adapter into the assembly. The one-step reduction from 5" to 4" keeps the size differential moderate — flow velocity increases minimally across the transition, which is a meaningful consideration in high-volume systems where pressure drop at the reduction point is an engineering factor.

The spigot end configuration means this bushing inserts into a receiving 5" socket fitting rather than receiving pipe into itself — making it the correct choice when the upstream fitting has a socket end that accepts a spigot. The hex shoulder on the bushing body bears against the face of the receiving fitting, locating the bushing correctly in the socket and providing a wrench flat for assembly.

Manufactured from virgin PVC compound to Schedule 40 dimensional standards, the 438-490 delivers solid pressure ratings for standard commercial and light industrial service at this diameter. Like all Schedule 40 PVC fittings, it is lightweight, corrosion-proof, and fully resistant to biological fouling and a broad range of chemicals encountered in plumbing, irrigation, and large-diameter process applications. Thread sealant should be applied at any male-threaded component threading into the FPT port to ensure a leak-free connection under operating pressure.

Specifications:

Industries & Applications:

• Municipal Water & Wastewater — Reducing a 5" socket fitting assembly to a 4" threaded valve, meter, or service connection on large-diameter distribution mains or collection system piping
• Irrigation Systems — Stepping down a 5" mainline socket fitting to a 4" threaded valve, backflow preventer, or pump connection in large commercial or agricultural irrigation infrastructure
• Industrial Process Piping — Transitioning a 5" solvent-weld process header to a 4" threaded equipment inlet or service valve in high-volume fluid distribution systems
• Water Treatment — Connecting large-diameter PVC socket fittings to 4" threaded control valves, flow meters, or inline instrumentation in treatment plant and pump station piping
• Commercial Plumbing — Reducing a 5" socket fitting to a 4" threaded branch or equipment connection in large commercial mechanical systems where a single-fitting transition is preferred over stacked components
• Agriculture — Adapting 5" PVC socket fittings to 4" threaded pump flanges, filter housings, or manifold inlets on high-volume agricultural water distribution and irrigation systems