Bushing, Spigot x Slip (Flush Style) PVC Schedule 80 3" x 1-1/2" (837-337)

The 3" x 1-1/2" PVC Schedule 80 Flush Style Bushing Spigot x Slip (837-337) provides a compact, low-profile inline size reduction from a 3" socket fitting to a 1-1/2" pipe continuation in a single fitting, with a flush-mount profile that seats entirely within the receiving socket rather than protruding beyond the fitting face. Manufactured from rigid gray PVC conforming to ASTM D1784 Cell Class 12454, this bushing is engineered for the pressure ratings, chemical resistance, and dimensional demands of industrial, municipal, and commercial Schedule 80 PVC piping systems.

The spigot (SPG) end is sized to the outside diameter of 3" Schedule 80 pipe, inserting directly into any standard 3" PVC socket fitting—such as a coupling, tee, cross, elbow, or valve body—as the male solvent-weld member of that joint. Once the spigot end is solvent-cemented into the receiving 3" socket, the bushing becomes a permanent, pressure-rated component of the fitting assembly. The slip (socket) end on the outlet then accepts standard 1-1/2" Schedule 40 or Schedule 80 PVC pipe via solvent cement, continuing the reduced pipe run from that point forward.

The flush style profile is the defining construction distinction from a standard hex head bushing. Where a hex bushing presents a raised shoulder that protrudes beyond the face of the receiving socket—adding axial length and requiring clearance for the hex flats—the flush style bushing eliminates the protruding shoulder entirely. The bushing body seats flush to or recessed within the receiving fitting face, producing a compact, streamlined assembly that is particularly valuable in tight equipment spaces, manifold assemblies, prefabricated skids, and dense valve trains where the protrusion of a hex shoulder would create dimensional interference or require a layout redesign to accommodate.

At 3" x 1-1/2", this bushing executes a two-nominal-size reduction—sitting between the single-step 837-339 (3"x2-1/2") and the larger reductions of the 837-338 (3"x2") and 837-335 (3"x1") within the 3" spigot group. The 1-1/2" outlet retains a meaningful flow cross-section, making this bushing appropriate not only for auxiliary service and instrumentation takeoffs but also for secondary branch lines, chemical feed mains, pump suction connections, and flow-carrying service lines where the 1" outlet of the 837-335 would be too restrictive but the one-step reduction of the 837-339 to 2-1/2" is not enough reduction for the application. This positions the 837-337 as the mid-range reduction option in the 3" spigot flush bushing family—versatile enough to serve both flow-carrying branch applications and compact service connections from large-diameter headers.

The flush profile additionally yields a cleaner interior flow transition, with the size reduction occurring within the socket depth and the bore stepping down in a controlled geometry. In continuous-duty flow applications at this size range, this contributes to a more hydraulically efficient assembly compared to a hex bushing whose shoulder geometry introduces a more abrupt flow path transition outside the fitting body.

Schedule 80 construction maintains consistent pressure class with surrounding Schedule 80 pipe and fittings throughout the system. Gray PVC delivers broad resistance to acids, bases, salts, and a wide range of industrial process fluids. For service temperatures above 140°F, consult CPVC Schedule 80 equivalents.

Specifications:

Industries & Applications:

• Chemical Processing — Mid-range size reductions from 3" process headers and manifold socket fittings to 1-1/2" chemical feed mains, dosing lines, and secondary process branch connections where a flush-profile bushing minimizes assembly footprint
• Water & Wastewater Treatment — Branch line reductions on pump station headers, treatment plant process piping, and chemical injection manifolds where a 3" to 1-1/2" flush bushing transitions a large header socket fitting to a flow-carrying secondary service line
• Industrial Manufacturing — Prefabricated Schedule 80 spool assemblies and process manifolds where dimensional constraints require a flush-profile reducer at the 3" to 1-1/2" size transition in space-limited equipment skid layouts
• Irrigation & Agriculture — Secondary zone supply and chemical injection line takeoffs from 3" Schedule 80 pump station headers and filter manifold socket fittings on commercial irrigation and fertigation systems
• Municipal Infrastructure — Service branch and instrumentation line reductions off 3" Schedule 80 mains at lift stations, treatment plants, and distribution system connection points where a compact bushing profile is required
• Aquaculture & Aquatics — Recirculating system secondary supply, dosing, and monitoring line connections off 3" header socket fittings in densely plumbed mechanical assemblies where the 1-1/2" outlet supports meaningful branch flow capacity
• HVAC & Plumbing — Commercial mechanical systems with Schedule 80 PVC piping requiring a flush-profile 3" to 1-1/2" reducer at secondary branch connections, equipment service ports, and auxiliary takeoffs from large-diameter headers