1" Union (O-Ring Type), Slip x FPT PVC Schedule 80 (899-010)

The 899-010 is a 1" PVC Schedule 80 O-ring type union in a slip x FPT (Slip x Female Pipe Thread) configuration, providing a fully removable connection point in a 1" PVC pipeline where one side of the union is solvent-welded and the other is threaded. The slip end accepts standard 1" pipe or a spigot-end fitting for permanent solvent cement bonding, while the FPT end accepts a 1" MPT nipple, fitting, or equipment port for threaded assembly — with the union body itself disconnectable and reconnectable at the slip nut without disturbing either the cemented or threaded end connection.

The mixed slip x FPT configuration is the defining practical advantage of the 899-010. In real-world PVC systems, the transition point between a solvent-welded pipeline and a threaded equipment connection — a pump, valve body, tank nozzle, or instrument port — is one of the most common locations where a union is needed. The 899-010 is purpose-built for exactly this junction, bridging the two joining methods in a single fitting while adding the disconnect capability that makes equipment service, seasonal removal, and system reconfiguration practical without pipe cuts.

The O-ring sealing mechanism delivers a clean, consistent, leak-free seal at the union joint. Rather than relying on a threaded or solvent-welded face-to-face connection, the union uses a captive elastomeric O-ring compressed between the two halves when the slip nut is tightened. This produces a seal that is easy to re-engage after disconnection, requires no sealant or cement at the union joint itself, and can be inspected and replaced independently if wear or chemical degradation occurs — extending the service life of the union body over multiple assembly cycles.

Schedule 80's thicker wall construction provides higher pressure ratings and stronger resistance to mechanical stress and chemical exposure than Schedule 40, making the 899-010 appropriate for demanding industrial, chemical, and process environments where the heavier wall and gray Schedule 80 construction are specified. The gray color provides clear visual differentiation from white Schedule 40 union components in mixed systems.

Installation on the slip end follows standard solvent cement practice — clean, prime, and cement per ASTM D2564 procedures, ensuring the pipe is fully seated before the cement sets. For the FPT end, apply PTFE thread tape or a compatible PVC-rated thread sealant to the male threads of the mating fitting before assembly. Avoid petroleum-based pipe dopes, which can degrade PVC over time. At the union joint itself, no sealant is needed — the O-ring provides the seal when the slip nut is hand-tightened and snugged.

Specifications:

Industries & Applications:

The 899-010 is well-suited for any Schedule 80 system requiring a serviceable disconnect point at the junction between a solvent-weld pipeline and a threaded equipment connection in a 1" line:

• Industrial Processing — Disconnect points at the interface between 1" Schedule 80 solvent-weld process piping and threaded pump ports, valve bodies, flow meters, and inline instruments where equipment must be removed or replaced without cutting into the cemented pipeline
• Chemical Handling — Serviceable union connections in acid, alkali, and reagent distribution systems at chemical metering pump connections, injection equipment ports, and threaded instrument interfaces — allowing pump heads, injectors, and sensors to be serviced independently of the permanent solvent-weld pipeline
• Water & Wastewater Treatment — Disconnect unions at chemical dosing pump connections, UV unit ports, filter vessel inlets, and threaded equipment interfaces in treatment plant piping where periodic equipment removal is required at the solvent-weld-to-threaded transition
• Irrigation & Agriculture — Serviceable connections at pump station equipment, filter housing ports, pressure regulator assemblies, and threaded control equipment in pressurized 1" Schedule 80 irrigation systems where seasonal removal or equipment swaps are anticipated
• Commercial & Industrial Plumbing — Union disconnect points at water treatment equipment, backflow preventer assemblies, and mechanical room equipment where the PVC pipeline transitions from solvent-weld to a threaded equipment port and periodic service access is required
• Aquaculture & Aquatics — Serviceable connections at UV sterilizer ports, pump equipment inlets, filter housing connections, and recirculating system instrumentation where the slip x FPT union allows equipment removal without disturbing the surrounding solvent-weld piping
• Pool & Spa — Disconnect unions at pump and filter equipment connections in commercial pool mechanical rooms where 1" Schedule 80 solvent-weld supply lines connect to threaded equipment ports requiring periodic service access
• Laboratory & Research Facilities — Serviceable disconnect points in Schedule 80 lab piping at threaded instrument ports, reagent equipment connections, and inline sensor interfaces where the union allows equipment removal without pipe cuts or cement joint disturbance