Product DescriptionThe AY MCDONALD 4423-386 is a 1-inch PEX-A poly insert plug designed to cap off open PEX-A tubing ends in plumbing and hydronic systems. Made from a polymer construction, this insert plug slides into the inside diameter of 1-inch PEX-A tubing to create a secure, leak-resistant termination point. Plumbers and pipefitters use this fitting during pressure testing, system commissioning, or when permanently capping unused branch lines. Its insert-style design ensures a firm mechanical fit within the tubing wall.This insert plug is suited for residential and light commercial plumbing installations where PEX-A tubing is the primary distribution material. Typical applications include potable water supply systems, radiant heating distribution manifolds, and hydronic baseboard or in-floor heating circuits. It is used wherever a branch line or tubing run needs to be terminated cleanly without cutting back the entire run.Key FeaturesInsert-style design fits securely inside 1-inch PEX-A tubingPolymer construction resists corrosion and scale buildupSuitable for pressure testing and permanent capping applicationsCompatible with standard PEX-A crimp and clamp installation methodsSold in single-unit increments with no minimum order quantity beyond oneCompatibilityDesigned as an OEM-style insert plug for use with 1-inch PEX-A tubing in residential and light commercial plumbing and hydronic heating systems.Installation NotesInstallation is performed by a licensed plumber following applicable IPC or local plumbing code requirements. Shut off the water supply and depressurize the line before inserting the plug. Secure the fitting using an appropriate PEX crimp ring or clamp ring tool rated for 1-inch fittings. Inspect the connection for proper seating before restoring system pressure.Technical SpecificationsTube Size: 1 inchFitting Type: Insert PlugMaterial: PolymerTubing Compatibility: PEX-AUPC: 811734022615Order Increment: 1Standard InformationBrand: AY MCDONALDManufacturer Part Number: 4423-386