Reducing Tee, Slip x Slip x Slip PVC Schedule 80 3" x 3" x 1-1/2" (801-337)

The 801-337 is a 3" x 3" x 1-1/2" Schedule 80 PVC Reducing Tee with Slip x Slip x Slip connections. This fitting maintains a full 3" cemented main run on both inline sockets while introducing a 1-1/2" slip branch socket off the side — all three connections are solvent-weld, making the entire assembly a fully cemented, permanent, pressure-rated branch fitting with no threaded ports. The two inline run sockets accept standard 3" Schedule 80 PVC pipe, preserving the full bore of the main line through the fitting, while the 1-1/2" branch socket receives 1-1/2" PVC pipe for a permanent cemented branch connection off the main run.

The 3" x 3" x 1-1/2" configuration represents a full two-increment reduction from main to branch — a step down that is more pronounced than the single-increment 3" x 2" reduction of the 801-338, and substantially larger than the minor service branches of the small-branch reducing tee variants in the 801/802 series. This size relationship places the 801-337 in a specific functional tier: the 1-1/2" branch is a meaningful downstream circuit connection — large enough to carry significant flow to a sub-circuit, equipment feed, or secondary distribution line — but at half the cross-sectional flow capacity of the 3" main it draws from. This is still a flow-distributing tee rather than an instrumentation or service port tee, but the two-increment reduction signals a more deliberate flow partition between the main and the branch than the single-step 801-338.

Common configurations where this size pairing appears include 3" distribution headers feeding 1-1/2" individual equipment connections — pump suction or discharge lines, filter inlets, chemical dosing equipment ports, and zone supply laterals — where the main must continue at full 3" capacity past the branch point while delivering a full 1-1/2" flow connection to the downstream circuit. The two-increment reduction also appears at header-to-branch transitions on water treatment plant piping, irrigation manifolds, and industrial process headers where the downstream sub-circuit or equipment group is specifically sized at 1-1/2" and the main runs at 3" throughout.

The all-slip configuration means every connection is a permanent solvent-welded joint — once cemented, no socket can be disassembled without cutting pipe. This is the standard configuration for permanent pressure piping systems where all branch and run connections are designed to remain in place for the service life of the installation. For applications where the 1-1/2" branch must terminate at a threaded valve, equipment port, or instrument connection rather than continuing as a cemented pipe run, the equivalent fitting with a 1-1/2" FPT branch port is the more efficient specification — it eliminates the need for a downstream slip-to-threaded adapter at the branch exit. The all-slip 801-337 is the correct choice when the 1-1/2" branch continues as a cemented PVC pipe run downstream of the tee.

The 801-337 is a direct sibling to the 801-338 (3" x 3" x 2" branch) in the same series — same run size, same schedule, same all-slip configuration, one additional increment of branch reduction. Buyers working through the 3" Schedule 80 reducing tee family should confirm the branch outlet size carefully before ordering, as adjacent part numbers in this series differ by a single digit and the correct SKU is determined entirely by the downstream branch pipe size required.

Proper solvent cementing practice at 3" is essential on both run sockets — a full two-step primer and cement application with thorough coverage of the complete socket interior and pipe end on both sides of the run, plus the same two-step approach on the 1-1/2" branch socket. On a tee, the run and branch sockets should be assembled in a deliberate sequence that allows each joint adequate set time before the adjacent connection is made, with each pipe held in alignment through the set period before the joint is allowed to cure undisturbed.

Specifications:

⚠️ Note: In a reducing fitting, the smaller end governs the pressure rating. All three sockets are permanent solvent-weld connections — once cemented, no connection can be broken without cutting pipe. Use primer before cementing all three sockets — do not skip the priming step on the 3" run sockets at this diameter. Confirm 801-337 (1-1/2" branch) vs. 801-338 (2" branch) before ordering — the two part numbers differ by a single digit and the branch socket sizes, while visually distinct from the 3" run sockets, are close enough in absolute dimension that confirmation before cementing is prudent. If the 1-1/2" branch must terminate at a threaded connection rather than continuing as cemented pipe, specify the FPT branch equivalent instead. Consult manufacturer derating tables for elevated-temperature service.

Industries & Applications:

• Water & Wastewater Treatment — Branches a full-flow 1-1/2" cemented sub-circuit or equipment feed off a 3" treatment plant distribution header, with the two-increment reduction allowing the branch to deliver a defined flow share to a downstream process circuit, dosing equipment connection, or filter inlet while the 3" main continues at full capacity through the fitting
• Chemical Processing — Used on 3" chemical distribution headers where a 1-1/2" cemented branch must supply a secondary chemical feed line, dosing sub-circuit, or equipment group that draws a meaningful but not dominant share of the main flow, with the all-slip assembly eliminating threaded joints at the branch point in corrosive-service piping
• Industrial Process Piping — Establishes 1-1/2" cemented branch connections off 3" process water, cooling water, and chemical distribution mains on plant piping systems and skid assemblies where the downstream branch circuit is specifically sized at 1-1/2" and all connections are designed as permanent solvent-welded joints
• Pump Station & Equipment Connections — Installed on 3" pump discharge or suction headers where a 1-1/2" cemented branch supplies a secondary pump circuit, equipment inlet, bypass line, or parallel sub-circuit requiring full 1-1/2" pipe capacity at the branch point without reducing the 3" main bore
• Irrigation & Agricultural Systems — Taps a 1-1/2" cemented zone supply lateral or equipment feed off a 3" pressurized distribution header at a manifold branch point, with the two-increment reduction appropriate for individual zone circuits or equipment connections that are deliberately sized at 1-1/2" rather than the 2" of larger-flow branch connections
• Municipal & Utility Infrastructure — Applied on 3" municipal water distribution mains and pump station headers where a 1-1/2" cemented service branch, building lateral, or sub-distribution run must be introduced at a defined junction point with the main continuing at full 3" bore past the branch connection