Union (O-Ring Type), Slip x Slip PVC Schedule 80 2" (897-020)

The 897-020 is a 2" Schedule 80 PVC Union with an O-ring seal, featuring Slip socket connections on both ends. This is a fully cemented union — both the inlet and outlet sockets accept solvent cement for a permanent bond to standard Schedule 80 PVC pipe on each side, making the entire pipe-side assembly a solvent-welded system with no threaded connections involved. The union itself, however, is disassemblable: the threaded union nut can be loosened and the two halves of the union body separated at the O-ring joint, breaking the line at that point for pump removal, valve replacement, equipment service, inline instrument access, or system modification — without cutting pipe, disturbing cemented joints upstream or downstream, or decommissioning the surrounding assembly.

The Slip x Slip configuration is the all-cemented union — both sides of the union bond permanently to the pipe, and the only serviceable point in the assembly is the union joint itself. This makes it the correct specification for systems built entirely on solvent-welded PVC pipe where the union is the designed break point: a pump isolation union, an equipment connection union, a valve service union, or a system access point on a cemented pressure line. Where one side of the union must connect to a threaded fitting or equipment port, the Slip x FPT version (899-020) is the appropriate alternative; where both sides connect to threaded ports, the FPT x FPT version (898-020) applies. The 897-020 is the right choice when both sides of the union connect to cemented PVC pipe runs and the union itself is the only mechanical joint in the assembly.

The O-ring seal design is the defining performance advantage of this union over flat-faced alternatives. As the union nut is tightened, the elastomeric O-ring compresses into a machined groove on the union face, creating a positive, leak-resistant pressure seal that is independent of face-to-face contact pressure alone. This produces a more consistent, reliable seal under sustained operating pressure, thermal cycling, and repeated assembly and disassembly cycles than a flat-face union, where seal integrity depends entirely on the contact force between the two mating faces. The O-ring type union is the preferred specification in chemical processing, water treatment, and industrial fluid handling applications where joint integrity over the full service life of the system — including multiple maintenance disassembly cycles — is a non-negotiable design requirement.

At 2", the 897-020 is a commonly specified union size across a wide range of commercial and industrial PVC pressure systems — appearing at pump connections, filter inlets and outlets, chemical dosing equipment tie-ins, inline strainer ports, and equipment access points on systems where 2" is the primary pipe size or where the system reduces to 2" at individual equipment connections. Schedule 80 wall thickness ensures the fitting meets the pressure and chemical resistance demands of industrial service environments where Schedule 40 would be underspecified.

The union nut should be tightened by hand to full engagement and finished with a strap wrench — do not use metal pipe wrenches or channel-lock pliers on the union nut, as point loading from metal jaws can distort or crack the nut seating surface. When disassembling, the O-ring should be inspected and replaced if it shows signs of compression set, cracking, or chemical degradation before the union is reassembled and returned to service.

Specifications:

⚠️ Note: Tighten the union nut with a strap wrench only — do not use metal jaw wrenches on PVC union bodies or nuts. Both slip sockets are permanent solvent-weld connections — once cemented, neither pipe-side connection can be broken without cutting pipe; only the union joint itself is disassemblable. Inspect and replace the O-ring if signs of wear, compression set, or chemical degradation are observed before returning the union to service after disassembly. Pressure ratings decrease at elevated temperatures; consult manufacturer derating tables for high-temperature service.

Industries & Applications:

• Chemical Processing — Provides a disassemblable break point in fully cemented chemical feed, distribution, and process lines at pump connections, filter housings, and inline equipment ports, allowing individual components to be removed for maintenance, calibration, or replacement without disturbing the surrounding solvent-welded piping assembly
• Water & Wastewater Treatment — Used at pump inlets and outlets, filter connections, chemical dosing equipment tie-ins, and UV system ports on treatment plant piping where both sides of the union connect to cemented PVC pipe runs and periodic equipment removal is a routine maintenance requirement
• Industrial Process Piping — Installed at designed service access points on 2" cemented process water, cooling water, and chemical lines where equipment or inline components must be periodically removed without cutting into the permanent piping assembly
• Pump Station & Equipment Connections — The primary application for the 2" all-slip union — installed on both the suction and discharge sides of pump connections on PVC pressure systems, allowing the pump to be isolated and removed without cutting the cemented supply and return lines
• Irrigation & Agricultural Systems — Used at pump connections, filter inlets and outlets, and chemical injection equipment tie-ins on pressurized irrigation systems where both sides of the union connect to cemented PVC pipe and seasonal or periodic equipment removal is required without modifying the pipe assembly
• Aquaculture & Commercial Pool/Spa — Applied at filter, heater, and pump connections in recirculating water systems where corrosion-resistant PVC is specified throughout and the all-cemented union provides a clean, permanent-pipe-side assembly with a fully serviceable union joint for equipment access