Tee, Slip x Slip x Fpt PVC Schedule 40 12" x 12" x 4" (402-664)

The 12" x 12" x 4" Schedule 40 White PVC Tee (402-664, Slip x Slip x FPT) is a large-diameter thermoplastic combination tee fitting manufactured to ASTM D2466 in Schedule 40 white PVC — a Spears 402 series socket-by-thread configuration in which the two run connections are 12" slip socket ends and the branch connection is a 4" female pipe thread (FPT) port accepting 4" male NPT threaded pipe, nipples, valves, and fittings. The 402-664 provides a single-body Schedule 40 PVC solution for taking a 4" threaded branch connection off a 12" solvent cement socket primary main — maintaining the full 12" solvent-cemented primary main construction through both run ports while providing a detachable, re-engageable, threaded branch interface at the 4" port for connection to the threaded components, threaded isolation valves, threaded pump connections, threaded instruments, threaded pressure relief assemblies, and threaded process equipment connections that the system's branch service requires. The defining specification advantage of the 402-664 over the all-socket 401 series reducing tee at the same size configuration is precisely this branch connection type distinction — the 4" FPT port eliminates the need for a threaded adapter or transition fitting between the PVC tee's socket branch port and the threaded branch component, provides a directly threaded female NPT interface at the branch port that accepts any standard 4" male NPT threaded component without intermediate fittings, and allows the branch connection to be made, inspected, serviced, tightened, and if necessary removed and re-engaged without cutting pipe, without solvent cement disassembly, and without any modification to the primary 12" solvent-cemented run piping.

The branch connection type — FPT rather than slip socket — is the specification decision that determines when the 402-664 is the correct fitting over the all-socket Schedule 40 reducing tee at the 12" x 12" x 4" configuration. The all-socket reducing tee is the correct specification where the branch pipe run is entirely PVC socket construction and the branch connection is a permanently bonded solvent cement joint — the standard specification for branch pipe runs in large commercial and municipal PVC primary main construction where the branch pipe continues in solvent cement socket PVC from the tee through zone valves, fittings, and distribution components in a fully integrated PVC piping system. The 402-664 with its 4" FPT branch is the correct specification where the branch connection is to a component whose inlet or outlet is male NPT threaded — where the system design specifies a threaded branch valve, a threaded pump connection, a threaded instrument or gauge assembly, a threaded chemical injection fitting, a threaded pressure relief valve, a threaded flow meter connection, or any other branch component that is inherently threaded at the 4" NPT connection size — eliminating the threaded socket adapter or street fitting that would otherwise be required between an all-socket tee's branch port and the threaded branch component, and providing the direct threaded female branch interface at the fitting body itself where the threaded connection's detachability, adjustability, and re-engagement capability without pipe cutting is a design or maintenance requirement.

The 12" x 12" x 4" FPT configuration reflects the most common large-diameter primary main threaded branch scenario in the commercial and municipal PVC system market — a 12" primary transmission or distribution main, constructed in solvent cement socket Schedule 40 PVC throughout, with a 4" threaded branch connection point where a specific branch component at 4" NPT thread size must connect directly to the primary main without an intermediate socket-to-thread adapter. The 4" branch at 33% of the 12" run diameter is a true lateral branch takeoff — a hydraulic relationship where the branch draws a modest fraction of the primary main flow with negligible effect on the 12" primary run's velocity and pressure profile through the straight-run ports, and the fitting functions as a single-point threaded service interface between the 12" primary infrastructure system and the 4" NPT-threaded branch component. This hydraulic character — large primary trunk, modest lateral threaded service tap — is consistent with the lateral branch applications where FPT branch tees are most frequently specified: pump discharge and suction connections where the pump's 4" NPT port connects directly to the primary main branch, pressure relief and bypass valve connections where the valve's 4" NPT inlet threads into the primary main branch port, instrument supply manifold connections where the instrument isolation valve's 4" NPT inlet is the primary system interface, and chemical injection assembly connections where the injection equipment's 4" NPT inlet connects directly to the primary main.

Schedule 40 white PVC construction provides the chemical resistance, NSF certification, and structural capability appropriate for large-diameter primary main service within the Schedule 40 pressure and wall thickness envelope. PVC Type 1 Grade 1 construction with cell classification 12454 per ASTM D1784 delivers broad chemical resistance across water treatment chemicals, process water service, industrial utility water, and the full range of non-solvent process fluids appropriate for Schedule 40 PVC primary main service at both the 12" run connections and the 4" FPT branch port. The white color provides the Schedule 40 material class identification at the primary main branch connection. The 12" run socket connections solvent cement directly onto standard 12" IPS Schedule 40 or Schedule 80 PVC pipe; at these 12" socket connections, heavy-body solvent cement rated for large-diameter PVC is mandatory, pre-planned assembly with both 12" pipe ends positioned before cement application begins is essential, complete circumferential heavy-body cement coverage across the full bonding surface of each 12" pipe end and fitting socket must be achieved, and full cure time compliance before any system pressurization is non-negotiable at this large-diameter primary main connection where the 12" socket joints are the most technically demanding in the commercial Schedule 40 PVC fitting line. The 4" FPT branch port accepts standard 4" male NPT threaded pipe, nipples, and fittings — apply PTFE tape or approved pipe thread sealant to the male NPT threads in the direction of thread engagement before threading into the 4" FPT port; engage hand-tight and advance with a strap wrench to the manufacturer's recommended engagement depth for 4" NPT PVC threaded connections; do not over-torque — PVC female pipe threads are more susceptible to cracking from over-engagement than metal threads and the manufacturer's torque specification for the 4" FPT port must be observed to prevent thread failure at the branch port; the threaded connection at the 4" FPT branch provides a detachable interface that can be disengaged by backing out the threaded male component — but only after the primary main has been depressurized and isolated, and only after confirming that the thread sealant condition will allow re-engagement with fresh sealant at the reinstalled connection.

NSF 61 certification lists this fitting for potable water contact, and NSF 14 covers compliance with applicable plastics piping material standards — making it the correct primary main threaded branch tee for municipal water treatment and distribution systems designed to Schedule 40 specifications, large potable water pump station connections, and large commercial and institutional water supply primary mains where NSF-listed materials are required at every fitting in the primary distribution system and Schedule 40 construction with a 4" FPT branch satisfies the design engineer's material class and connection type requirements at the threaded branch service point. ASTM D2466 governs Schedule 40 PVC socket fittings; the 4" FPT thread form conforms to ANSI/ASME B1.20.1 NPT thread standards. Verify manufacturer pressure rating documentation for the specific fitting configuration before final system specification — at the 12" x 12" x 4" FPT combination tee configuration, the governing pressure rating is determined by the largest port size (12") and the fitting's tested performance at this large-diameter slip-by-thread combination tee geometry, and must be confirmed against the manufacturer's published pressure-temperature rating table for SKU 402-664 before installation in systems at or near the fitting's rated pressure ceiling.

Key Features:

• Schedule 40 white PVC combination tee — 12" slip x slip run x 4" FPT branch; Spears 402 series socket-by-thread
• Mixed end connection configuration — 12" solvent cement socket run ports x 4" female NPT threaded branch port
• 4" FPT branch accepts standard 4" male NPT threaded pipe, nipples, valves, instruments, and fittings directly without intermediate adapter fittings
• Detachable threaded branch connection — 4" FPT port allows branch component removal, inspection, and re-engagement without cutting pipe or disturbing the solvent-cemented 12" primary main
• True lateral branch geometry — 4" branch at 33% of 12" run diameter; primary 12" straight-run flow path maintained at full diameter
• Correct specification over all-socket reducing tee where branch component is male NPT threaded at 4" connection size
• Manufactured to ASTM D2466 — governing standard for Schedule 40 PVC socket fittings; 4" FPT thread per ANSI/ASME B1.20.1 NPT
• NSF 61 certified for potable water contact; NSF 14 listed
• 12" slip socket connections compatible with Schedule 40 and Schedule 80 IPS pipe
• White color — standard Schedule 40 material class identification
• Cell classification PVC 12454 per ASTM D1784
• Heavy-body solvent cement required at both 12" socket connections; full cure time mandatory before pressurization
• PTFE tape or approved pipe thread sealant required at 4" FPT branch; do not over-torque — observe manufacturer torque specification for 4" NPT PVC threaded connections
• Pressure rating: verify against manufacturer pressure-temperature table for SKU 402-664

Specifications:

Industries & Applications:

• Pump Station — Threaded Pump Connection Branch Off 12" Primary Header — The 12" x 12" x 4" FPT Schedule 40 tee is specified at primary pump station header locations where the 12" solvent cement socket primary discharge or suction header must supply a 4" NPT threaded branch connection to a pump's 4" male NPT suction inlet, discharge outlet, pressure relief port, or bypass connection; the FPT branch port eliminates the socket-to-thread adapter fitting that would otherwise be required between an all-socket tee branch port and the pump's threaded connection, providing a direct female NPT interface at the 12" primary header branch point for attachment of threaded pump isolation valves, threaded pump inlet flanged adapters with NPT stubs, threaded check valve assemblies, threaded pressure relief valve inlet connections, and threaded bypass valve assemblies at pump stations where Schedule 40 PVC is the specified system material and the 12" primary header must supply a 4" NPT threaded branch connection without an intermediate adapter assembly; the threaded branch's detachability is operationally significant at pump station branch connections where pump components may require periodic removal for inspection, maintenance, or replacement without disturbing the 12" solvent-cemented primary main — a maintenance requirement that the 4" FPT branch port's re-engageable threaded connection serves that a solvent-cemented socket branch cannot
• Municipal Water Distribution — Threaded Instrument and Valve Branch Connections on 12" Primary Mains — Installed at 4" NPT threaded branch connection points on 12" municipal water transmission and primary distribution mains in Schedule 40 PVC systems where the primary main must supply a threaded branch to a 4" male NPT pressure gauge manifold assembly, a 4" NPT threaded isolation valve for a sample tap or instrument supply connection, a 4" NPT threaded air release valve assembly, a 4" NPT threaded pressure relief valve inlet, a 4" NPT threaded blow-off assembly, or a 4" NPT threaded corporation stop or service connection assembly; the FPT branch port provides the direct NPT interface at the 12" primary main branch point for these inherently threaded municipal water system branch components — eliminating the intermediate socket-to-thread adapter and providing the detachable threaded connection that municipal water system maintenance standards frequently require at instrument, sample, and pressure relief branch connections so that these components can be removed, inspected, and replaced without cutting the primary main; NSF 61 listing confirms potable water fitness at every municipal water distribution threaded branch connection
• Water Treatment Plant — Threaded Chemical Injection and Instrument Branch Connections — Used at 4" NPT threaded branch connection points on 12" primary distribution headers in water treatment plants where the primary header must supply a 4" NPT threaded branch to chemical injection assemblies, flow control valve inlets, pressure transmitter isolation valve manifolds, sampling system inlet connections, chemical metering pump discharge connections, and instrument supply headers requiring a directly threaded 4" NPT interface at the 12" primary header branch point; chemical dosing and instrumentation equipment in water treatment plants is frequently specified with male NPT threaded connections at the 4" service size — the 402-664's 4" FPT branch provides the direct PVC female NPT interface that receives these components without the intermediate socket-to-thread adapter that an all-socket tee branch would require; the threaded branch connection at chemical injection and instrument service points also provides the detachability that maintenance and calibration programs require — the ability to remove, service, and reinstall instrument assemblies and dosing equipment at the primary header branch point without disturbing the permanently bonded 12" solvent cement main; NSF 61 listing confirms potable water fitness at every water treatment plant threaded branch connection
• Industrial Process Piping — Threaded Branch Connections to Process Equipment and Instruments — Specified at 4" NPT threaded branch connection points on 12" process water primary headers, cooling water primary distribution trunks, and plant utility water primary mains in manufacturing plants, chemical processing facilities, and industrial environments where the 12" Schedule 40 PVC primary header must supply a 4" NPT threaded branch to process equipment with male NPT inlet connections, threaded isolation and control valves serving individual equipment points, threaded pressure and flow instrument manifolds, threaded safety relief valve inlets, threaded drain valve assemblies, and threaded sampling and analysis point connections; in industrial process piping, the transition from large-diameter PVC socket piping to threaded process equipment connections is a common design requirement — equipment is frequently specified with NPT threaded connections at 4" service size, and the 402-664 provides the single-body Schedule 40 PVC fitting that accomplishes this socket-to-thread transition at the 12" primary header branch point without intermediate adapters; the threaded branch connection's detachability is a maintenance requirement at process equipment connections where valve and instrument removal for calibration, maintenance, and replacement is a routine operational activity
• Large Commercial & Agricultural Irrigation — Threaded Valve and Instrument Branch Connections on 12" Primary Mains — Used at 4" NPT threaded branch connection points on 12" primary irrigation transmission mains in Schedule 40 PVC systems where the primary main must supply a 4" NPT threaded branch to zone isolation valve assemblies with threaded inlets, threaded air and vacuum relief valve assemblies, threaded pressure gauge manifold connections, threaded chemical injection and fertigation equipment inlets, threaded flush valve assemblies at primary main endpoints, and threaded flow meter connections at primary zone supply points; irrigation system valves and control components at the 4" service size are frequently specified with male NPT connections — the 402-664 provides the direct female NPT branch interface at the 12" primary main for attachment of these threaded irrigation system components without intermediate adapters; the threaded connection's serviceability is operationally important at irrigation valve and instrument branch points where seasonal maintenance, component replacement, and system modification are routine activities requiring removal and reinstallation of branch components without cutting the 12" primary transmission main
• Fire Protection and Hydrant Supply — Threaded Branch Connections on 12" Fire Mains — Specified at 4" NPT threaded branch connection points on 12" Schedule 40 PVC fire protection supply mains, hydrant supply laterals, and standpipe supply headers in systems where the 12" PVC primary supply main must provide a 4" NPT threaded branch connection to fire hydrant supply assemblies with NPT threaded connections, fire department connection (FDC) supply branch inlets, pressure relief and pressure regulating valve inlets at 4" NPT thread size, and standpipe supply isolation valve inlets with male NPT connections; at fire protection supply mains where 4" NPT threaded components must connect directly to the 12" Schedule 40 PVC primary supply header, the 402-664 provides the direct socket-by-thread interface fitting that eliminates the intermediate adapter between the primary main and the threaded fire protection branch component; verify with the authority having jurisdiction (AHJ) and the project's fire protection engineer that Schedule 40 PVC and the 402-664's pressure rating satisfy all applicable fire protection system code and specification requirements before installation in fire protection service
• HVAC & Large Commercial Mechanical Systems — Threaded Branch Service Connections on 12" Primary Distribution Mains — Used at 4" NPT threaded branch service connection points on 12" primary chilled water distribution mains, condenser water primary trunks, and large-capacity hydronic heating and cooling primary distribution headers in Schedule 40 PVC systems where the 12" primary distribution main must supply a 4" NPT threaded branch to air separator and air release valve assemblies with NPT threaded connections, pressure relief valve inlets, pressure gauge and transmitter isolation valve manifolds, drain valve assemblies at primary main low points, chemical treatment injection port assemblies, and balancing valve inlets at primary main branch supply points; the threaded branch connection at HVAC primary distribution service points provides the detachability that mechanical system commissioning, seasonal maintenance, and system rebalancing activities require — the ability to install, adjust, and remove branch service components at primary distribution points without disturbing the permanently bonded 12" solvent cement primary main construction; Schedule 40 PVC construction satisfies the material specification at primary distribution service branch connections in large commercial mechanical systems where Schedule 40 is the system material standard
• Industrial Water & Wastewater Treatment — Threaded Chemical Feed and Instrument Branch Connections — Installed at 4" NPT threaded branch connection points on 12" primary process distribution headers in industrial wastewater treatment, water reclamation, and large-scale industrial water management facilities where the primary header must supply 4" NPT threaded branches to chemical feed pump discharge connections, polymer dosing equipment inlets, pH and chlorination probe insertion assemblies with NPT threaded bodies, flow measurement device inlet connections, pressure relief valve inlets at primary header protection points, and sampling system inlet connections requiring a directly threaded 4" NPT interface at the 12" primary process header; treatment facility chemical feed and analytical instrumentation equipment is specified with male NPT connections at the 4" service size across virtually all process industry equipment categories — the 402-664 provides the direct female NPT branch interface in a single Schedule 40 PVC tee body that eliminates the socket-to-thread adapter chain that an all-socket tee would require at every threaded equipment branch connection in the primary treatment process distribution system