Bushing, MPT x FPT (Flush Style) PVC Schedule 80 3" x 1-1/2" (839-337)

The 839-337 is a 3" x 1-1/2" PVC Schedule 80 flush style bushing with a 3" male pipe thread (MPT) inlet and a 1-1/2" female pipe thread (FPT) outlet, designed to reduce a 3" female-threaded port down to a 1-1/2" male-threaded connection within a single compact threaded fitting. The 3" MPT inlet threads directly into any standard 3" FPT fitting, valve, or equipment port, while the 1-1/2" FPT outlet accepts any standard 1-1/2" NPT male-threaded pipe, fitting, valve, or instrument connection — creating a fully threaded, one-step reducing transition with no solvent welding required at either end.

Manufactured from rigid, dark gray PVC compound conforming to ASTM D1784 cell classification requirements, the Schedule 80 wall construction delivers higher pressure ratings and greater mechanical strength than Schedule 40 equivalents at the same pipe size. This makes the 839-337 the correct choice for high-pressure chemical lines, industrial process piping, and any Schedule 80 system where a threaded reducing transition must maintain full Schedule 80 pressure integrity throughout. PTFE thread tape or appropriate thread sealant should be applied to both the MPT inlet threads before engagement with the receiving FPT port, and to any MPT fitting assembled into the FPT outlet, to ensure leak-resistant seals at both thread interfaces.

The flush style designation distinguishes this bushing from a hex bushing — rather than a hex shoulder that extends proud of the fitting face, the flush bushing body sits flush within the receiving female port with no protruding hex wrench flats, creating a lower-profile installation in confined spaces and compact assemblies where a hex bushing's external shoulder would interfere with adjacent fittings, enclosure walls, or structural members. Among the 3" inlet flush bushing series, the 839-337 performs a substantial 1-1/2" reduction — larger than the half-inch step-down of the 839-339 (3" x 2-1/2") and the one-inch reduction of the 839-338 (3" x 2"), making this the appropriate bushing when a 3" threaded port must be reduced to a mid-size 1-1/2" connection for valve bodies, instruments, chemical injection equipment, or secondary service lines where the downstream connection is meaningfully smaller than the upstream port. At this reduction magnitude, the 839-337 functions as a genuine flow-reducing transition rather than a port-matching adapter, making application context and downstream flow requirements the primary sizing consideration for buyers choosing between this SKU and adjacent members of the series. The all-threaded construction means both ends remain serviceable — the bushing can be removed and replaced without cutting pipe or disturbing upstream or downstream solvent-welded connections.

Specifications:

Industries & Applications:

• Industrial Process Piping — Substantial threaded reductions in high-pressure Schedule 80 chemical distribution, cooling water, and process fluid systems where a 3" equipment port must be reduced to a 1-1/2" connection for downstream valve bodies, instruments, and secondary service lines
• Chemical Processing — Corrosion-resistant threaded reducing transitions in acid, caustic, and aggressive fluid service where all-PVC flush bushing construction eliminates metal corrosion, galvanic incompatibility, and contamination concerns at the reduction point and the downstream 1-1/2" connection serves chemical dosing, sampling, or secondary feed functions
• Municipal Water & Wastewater — Reducing 3" threaded equipment ports to 1-1/2" connections at pump stations, treatment facility equipment, and distribution system valve assemblies where a mid-size secondary service connection is required at a large-diameter threaded port
• Irrigation & Agriculture — Threaded reductions in high-pressure mainline valve assemblies and pump station manifolds where a 3" equipment port must interface with 1-1/2" zone valve bodies, filter connections, or secondary supply line assemblies
• HVAC & Mechanical — Threaded reducing connections at large-diameter equipment ports in chilled water and condenser water systems where downstream 1-1/2" valve, strainer, or balancing connections are required and flush style construction minimizes fitting profile in tight mechanical room installations
• Water Treatment & Filtration — Reducing connections at 3" filter vessel nozzles, pump equipment ports, and valve assemblies to 1-1/2" chemical dosing, sampling, and secondary service connections in potable water and industrial water treatment systems