Description
The Spears® 436 series is the male adapter you pull off the shelf when a 1 in. PVC schedule 40 lateral needs to thread into a brass valve, pump fitting, irrigation valve manifold, or any female-NPT-threaded port. Male NPT threads on one end, smooth solvent-weld socket on the other. Molded white PVC, Spears USA, domestic-manufactured to schedule 40 / standard dimensions, NSF-certified for potable water.
Why You’d Reach for a 436
- Male NPT (MIPT / MNPT) outlet — tapered male pipe thread per ANSI / ASME B1.20.1; mates with any female NPT fitting (brass, PVC, ductile iron, etc.) using PTFE tape or pipe dope
- Solvent-weld socket inlet — primed and cemented for a chemically-welded joint to schedule 40 PVC pipe; joint is as strong as the pipe wall
- Molded PVC (Type I), white — chemically resistant to dirt, soil acids, irrigation fertilizers, chlorine, and typical municipal-water chemistry
- Schedule 40 / standard dimensions — matches any schedule 40 PVC pipe and fitting; full pressure rating in the system
- Domestic, U.S. manufacture — Spears computer-stress-analyzed mold design with reinforced material at thread roots; NSF-pw certified for potable water service
- Length: 1-23/32 in. (3/4 in. variant) / 2-1/16 in. (1 in. variant) — standard footprint, fits any valve manifold or trench layout
Where It Fits in the System
- Sprinkler valve manifold: threads a Hunter PGV, Rain Bird DV, or similar female-NPT-threaded valve into a PVC lateral. The PVC side solvent-welds to schedule 40; the threaded side tapes-and-tightens into the valve inlet/outlet.
- Pump suction / discharge plumbing: the brass / cast iron pump bodies of Goulds, Pentair, etc. take MNPT pipe threads. The 436 makes the transition from rigid PVC suction line to the threaded pump port.
- Pond and water feature equipment: skimmer, return jet, UV sterilizer, and most pond filter bulkheads use female NPT ports.
- Bulkhead and tank fittings: filter housings, expansion tanks, and storage cisterns have MNPT or FNPT bosses; the 436 transitions PVC plumbing onto the threaded interface.
- Field hose-bib and frost-free connections: brass hose bibs / frost-free hydrants on the wall side accept the 436’s MNPT directly.
Size Differences
- 3/4 in. (Model 436-007, SKU 50811) — 3/4 in. nominal pipe, 1-23/32 in. overall length, 1-5/16 in. width across flats. The size for typical residential sprinkler lateral runs.
- 1 in. (Model 436-010, SKU 50805) — 1 in. nominal pipe, 2-1/16 in. overall length, 1-5/8 in. width across flats. The size for sprinkler mainlines, pump discharge, and most pond / pool plumbing.
Specifications
- Manufacturer: Spears Manufacturing Company
- Series: 436 (standard SCH 40 male adapter, MNPT × Socket)
- Type: standard male adapter, schedule 40 PVC
- Inlet: solvent-weld socket (slip)
- Outlet: male NPT thread (MIPT / MNPT)
- Material: PVC, Type I, molded white
- Pressure rating: matches schedule 40 PVC pipe of the same nominal size
- Operating temperature: 33°F to 140°F (PVC max service temperature)
- Origin: domestic, U.S.A.
- Certifications: NSF-pw (potable water service), Spears USA mark
- Reference standard: ASTM D2466 (PVC pressure fittings)
Installation Notes
Threaded end into female NPT fitting: 2 to 3 wraps of PTFE thread tape (or pipe dope) on the male threads, going in the direction of tightening (clockwise looking at the male end). Hand-tighten plus 1 to 2 turns with a strap wrench. DO NOT over-tighten — PVC threads cannot take the same torque as steel. If you can’t stop a leak at hand-tight + 2 turns, replace the tape and try again rather than cranking harder. Over-tightening is the #1 cause of cracked PVC male adapters in the field.
Socket end onto PVC pipe: Apply Spears P-70 (or equivalent) PVC primer to both the pipe end and the inside of the socket. Apply medium-bodied PVC solvent cement to both surfaces. Push the pipe fully into the socket and rotate 1/4 turn to spread the cement. Hold for 30 seconds. Cure 1 hour before low-pressure water test; 24 hours before full operating pressure.
Sealing strategy at the threaded joint: The taper of NPT threads should self-seal at the apex of the thread engagement — the PTFE tape is a lubricant and a gap-filler, not the primary seal. If the joint leaks at proper torque, the threads are damaged or the fitting is over-tightened. Replace the part rather than adding more tape.
What’s in the Box
- One Spears 436 series male adapter in your selected nominal size (3/4 in. or 1 in.), bulk-packed
Compatible Accessories — Sold Separately
- PTFE thread tape (white for PVC; pink heavy-duty for stainless / metal-on-metal)
- Spears P-70 PVC primer (purple) for the socket joint
- Spears PVC solvent cement (medium body, for pipe up to 6 in.)
- Strap wrench (the right tool to tighten PVC male adapters without crushing the threads)
- Schedule 40 PVC pipe and additional fittings (couplings, tees, elbows)
- Spears 474 series insert adapters (insert × socket) for transitions to flexible poly
Stop by Garoppo’s to pick one up, or schedule local delivery within our service area.