Coupling, Slip x Slip PVC Schedule 40 3/8" (429-003)

This 3/8" Schedule 40 PVC Coupling (Slip x Slip) provides a straight-through inline connection for two 3/8" PVC pipe ends in all-socket piping systems — the standard fitting for joining, extending, or repairing 3/8" all-cemented PVC pipe runs without introducing directional changes or size reductions into the assembly. Constructed in white Schedule 40 PVC, it serves the specialized small-bore socket applications where 3/8" nominal pipe size is specified — instrument tubing distribution runs, laboratory fluid handling assemblies, analytical system supply lines, small-bore process water socket assemblies, and dedicated instrument supply distribution networks where 3/8" is the required pipe size throughout and a straight-through inline socket connection is needed at pipe joining points.

Both the inlet and outlet are 3/8" slip socket ends, each accepting the exterior of a standard 3/8" PVC pipe end for a permanent solvent-cement bond per ASTM D2564 procedures — creating a continuous, leak-free inline connection at each cemented joint. As the fundamental straight-through connector in all-socket PVC assemblies at this specialized small-bore diameter, the slip coupling joins two 3/8" pipe ends in a continuous inline run — at pipe extension joints where a 3/8" instrument or laboratory distribution run must be lengthened beyond available pipe section lengths, at cut-in repair sections where a damaged 3/8" pipe segment must be replaced inline, and at assembly boundary connection points where two pre-assembled 3/8" socket pipe sections must be joined at the final connection point without a direction change. The slip coupling requires pipe ends on both sides — distinct from any FPT x FPT threaded coupling at 3/8" (if stocked), which would join two male-threaded components rather than cementing to pipe ends; and from any reducing coupling in the 429 series, which reduces between two different diameters rather than maintaining the same 3/8" diameter on both ends. At 3/8", this coupling carries an elevated pressure rating — consistent with the inverse relationship between nominal pipe size and pressure capacity in Schedule 40 PVC socket fittings confirmed throughout this catalog session — making it well suited for the higher-pressure instrument and process piping applications where 3/8" PVC socket construction is specified.

The Schedule 40 pressure capacity at 3/8" already represents the upper end of the standard Schedule 40 PVC socket fitting pressure range, making 429-003 suitable for the most demanding small-bore instrument distribution and process water applications within the Schedule 40 pressure class. NSF/ANSI 61 listing confirms suitability for potable water contact.

Apply solvent cement to both the pipe end exterior and the fitting socket interior per ASTM D2564 procedures at each port, using a primer appropriate for the pipe and fitting schedule. Insert pipe fully into each socket and maintain a quarter-turn during assembly for even cement distribution across the joint surface. At 3/8", the pipe end and socket diameters are small — ensure full insertion depth is achieved and excess cement is minimized to avoid blocking the bore. Allow adequate cure time before pressurizing the system, and derate pressure ratings for elevated temperatures per published derating curves.

Specifications:

Industries & Applications:

• Instrument & Process Piping — Joins, extends, and repairs 3/8" socket PVC instrument tubing distribution runs, sample system supply lines, and small-bore instrument fluid distribution assemblies at pipe extension joints and repair sections in manufacturing, water treatment, and laboratory facilities where 3/8" all-socket cemented PVC construction is specified for dedicated instrument supply and distribution networks requiring straight-through inline pipe connections throughout
• Laboratory & Analytical Systems — Provides straight-through inline connections between 3/8" socket PVC pipe run sections at extension joints and assembly boundary connection points in laboratory, analytical, and pilot plant fluid distribution systems where 3/8" is the required pipe size for dedicated reagent supply, sample distribution, or process fluid handling assemblies requiring all-socket cemented construction throughout
• Chemical Process Piping — Connects and extends 3/8" socket PVC pipe run sections in small-bore chemical feed distribution assemblies, analytical instrument supply lines, and dedicated process fluid handling pipe runs in chemical processing facilities where 3/8" all-socket construction is specified and straight-through inline connections at pipe joining and extension points must maintain full chemical resistance throughout the cemented assembly
• Water Treatment & Aquaculture — Used at inline straight-through pipe joining points on 3/8" all-socket instrument supply runs, small-bore chemical dosing distribution lines, and dedicated process fluid distribution pipe assemblies where NSF/ANSI 61 compliance and chemical resistance are required at every cemented connection throughout the all-socket small-bore distribution assembly
• Industrial Process Piping — Provides straight-through inline connections between 3/8" socket PVC pipe sections on dedicated instrument supply headers, small-bore process water distribution runs, and specialized service pipe assemblies in manufacturing and process facilities where 3/8" all-socket cemented construction is required and straight-through inline pipe joining is needed at multiple points throughout the distribution layout
• HVAC & Mechanical Systems — Joins 3/8" socket PVC pipe sections at inline connection points on small-bore instrument tap supply runs, sensor feed distribution lines, and dedicated small-bore service assemblies in HVAC and mechanical system installations within the Schedule 40 pressure class where straight-through inline connections maintain all-socket construction integrity throughout the 3/8" distribution assembly