3 inch Mechanical Gripper Plug

3 inch Mechanical Test Plug – Cherne Gripper Series

The 3 inch Cherne Gripper Plug is a mechanical test plug designed for sealing open pipe ends in non-pressurized systems during testing, temporary shutdowns, or system isolation. It features a rubber gasket expansion design actuated by a stainless steel wing nut and internal metal components, allowing reliable pipe sealing in DWV (drain, waste, and vent) systems.

This plug is engineered for use in cast iron, PVC, or ABS pipe with nominal 3 inch internal diameter. The zinc-plated steel hardware provides corrosion resistance in typical job site conditions. Designed to meet jobsite safety and performance demands, the Cherne Gripper plug offers repeatable installation and removal for re-use across multiple applications.

Technical Specifications

• Manufacturer: Cherne Industries
• Model: Gripper Plug – 3 inch
• Pipe Compatibility: 3 inch nominal DWV pipe (PVC, ABS, cast iron)
• Construction: ABS or glass-filled nylon body, rubber gasket, zinc-plated or stainless steel components (varies by model)
• Type: Mechanical expansion plug – internal seal with compression wing nut
• Max Back Pressure: Rated for up to 17 psi or 40 ft of head (depending on plug variant)
• Compliance: Suitable for temporary test use in accordance with plumbing code requirements

Installation Guidelines

Insert plug fully into clean pipe end. Tighten the wing nut using hand torque or tool-assisted methods, as appropriate for jobsite conditions. Do not exceed the manufacturer’s torque or pressure ratings. This plug is not rated for pressurized gas or long-term permanent sealing applications. Inspect gasket and hardware before each use to ensure proper function and system integrity.

Common Applications

Used primarily for DWV testing in new construction and remodeling, temporary sealing during hydrostatic or air testing, or isolating sections of pipe during maintenance. Appropriate for both residential and commercial plumbing systems. Not suitable for continuous pressurized fluid systems or high-temperature service without additional product verification.

Material Notes

The body material (nylon or ABS) provides dimensional stability and chemical resistance in typical jobsite conditions. The mechanical seal design allows for tool-free reusability across multiple installations. Choose stainless steel hardware versions for use in corrosive or wet environments where extended durability is required.

The 3 inch Cherne Gripper Plug is a jobsite-tested solution for temporary pipe isolation and system integrity testing in DWV installations. It provides mechanical reliability, code-appropriate performance, and quick setup in field conditions.