Bushing, MPT x FPT (Flush Style) PVC Schedule 80 1-1/4" x 3/4" (839-167)

This 1-1/4" × 3/4" Schedule 80 PVC Flush Bushing provides a compact, all-threaded one-step size reduction from a 1-1/4" female-threaded port down to a 3/4" male-threaded connection. The 1-1/4" MPT exterior threads directly into any compatible 1-1/4" FPT port — on a tee branch, cross outlet, valve body, equipment nozzle, or threaded coupling — while the 3/4" FPT interior receives any compatible 3/4" male-threaded fitting, nipple, valve, or instrument connection on the reduced side.

The one-step reduction from 1-1/4" to 3/4" is one of the most practical size transitions in commercial and industrial threaded piping. The 3/4" NPT port is among the most common connection sizes across standard valves, pressure gauges, strainer bodies, flow meters, and process instrumentation — making this bushing a high-frequency component wherever a 1-1/4" threaded port must interface with the broad range of 3/4"-ported equipment in commercial and industrial service. Rather than threading in a full-size adapter and then adding a downstream reducing coupling or bushing, the 839-167 accomplishes the port-to-component size match in a single fitting at the 1-1/4" port face.

As an all-threaded fitting, the 839-167 is the correct selection wherever the receiving port is female-threaded — distinguishing it from the 838-series flush bushing, which carries a spigot end for installation into slip socket ports. When the port to be reduced is FPT, the 839 MPT end threads directly in; when the port is a slip socket, the 838 spigot end is the appropriate choice. Both produce the same 3/4" FPT outlet at the reduced side, but serve opposite upstream connection types.

The flush style eliminates the protruding hex shoulder of a standard hex bushing, producing a low-profile, streamlined assembly that installs cleanly inside the receiving FPT port without adding axial length to the connection. This is particularly advantageous in threaded manifold assemblies, valve body ports, and equipment nozzles where hex shoulder clearance would create interference with adjacent components or restrict wrench access to nearby fittings.

Manufactured in dark gray Schedule 80 PVC, this bushing delivers the increased wall thickness and mechanical strength required in industrial, chemical, and commercial pressure piping where Schedule 40 ratings are insufficient. PVC's broad chemical resistance covers acids, bases, salts, chlorine, and most common process fluids, providing long service life in corrosive environments where metal bushings would corrode, seize on threads, or contaminate the fluid stream. NSF/ANSI 61 listing confirms suitability for potable water contact.

Rated to 630 psi at 73°F (governed by the 1-1/4" MPT end), this bushing handles standard to elevated pressure service across a wide range of fluid handling applications. Apply PTFE tape or compatible thread sealant to the 1-1/4" MPT exterior before threading into the receiving FPT port. Hand-tighten plus one to two turns — do not over-torque PVC threads, as excessive force risks cracking the receiving fitting or the bushing body at the thread engagement zone. Apply PTFE tape or thread sealant to all male threads engaging the 3/4" FPT interior before installing downstream components. Apply published pressure derating factors for service temperatures above 73°F.

Specifications:

Industries & Applications:

• Industrial Process Piping — Reduces a 1-1/4" FPT port on a tee branch, cross outlet, valve body, or equipment nozzle to a 3/4" male-threaded connection for valves, strainers, flow meters, and instrumentation in chemical processing, water treatment, and manufacturing facility piping — a common one-step size transition given the prevalence of 3/4" NPT ports on standard industrial equipment at secondary header and branch connection sizes
• Commercial Plumbing — Installs at 1-1/4" FPT branch outlets on threaded tees, manifold assemblies, and valve bodies in mechanical room and building water distribution piping to reduce to a 3/4" threaded connection at pressure gauges, shutoff valves, fixture supply branches, and backflow preventer test ports
• Water & Wastewater Treatment — Provides a compact all-threaded one-step size reduction at 1-1/4" FPT ports on process headers, chemical dosing manifolds, sampling assemblies, and instrumentation connection points along Schedule 80 PVC threaded piping in municipal and industrial water treatment facilities
• Chemical Handling & Dosing Systems — Delivers a corrosion-resistant threaded size reduction at 1-1/4" FPT ports on chemical feed manifolds, reagent distribution headers, and tank outlet fittings where downstream components present 3/4" male-threaded inlets in systems handling acids, caustics, and aggressive process fluids
• Irrigation & Agricultural Systems — Reduces 1-1/4" FPT branch ports on threaded tees, zone headers, and manifold assemblies to 3/4" male-threaded connections for control valves, pressure regulators, fertigation injectors, and filter drain fittings in commercial irrigation, greenhouse, and agricultural water supply systems
• HVAC & Mechanical Systems — Installed at 1-1/4" FPT ports on threaded Schedule 80 PVC cooling tower makeup lines, treated water distribution headers, and glycol system branch connections where a compact all-threaded one-step reduction to 3/4" is required at valve, gauge, and instrument connection points