Merit Brass 3417DA-04 Square Head Pipe Plug 1/4 in Ss

Product Description

The MERIT BRASS 3417DA-04 is a square head pipe plug designed to seal threaded pipe ends in pressurized fluid and gas systems. Machined from 304/304L stainless steel, it provides corrosion resistance in demanding environments including water, steam, and mild chemical service. The male NPT (MNPT) thread seats into standard female NPT fittings for a secure, pressure-tight closure. Rated to 3,000 psi, this plug handles the working pressures found in most commercial plumbing, industrial process piping, and HVAC hydronic systems. Plumbers, pipefitters, and mechanical contractors install this type of fitting during pressure testing, system commissioning, and port blanking procedures.

The 3417DA-04 is suited for residential and light commercial piping applications where a corrosion-resistant threaded plug is required. Common use cases include capping test ports, sealing unused branch connections, and blanking tee or cross outlets during system modifications. The 1/4 inch MNPT thread size fits standard quarter-inch female NPT pipe fittings found throughout plumbing, HVAC hydronic, and compressed-air distribution systems.

Key Features

• 304/304L stainless steel construction resists corrosion in wet and mildly corrosive service environments
• 3,000 psi pressure rating handles high-demand pressurized piping applications
• Male NPT (MNPT) threaded end connection seals into standard female NPT fittings
• Square head drive allows installation and removal with a standard wrench
• 1/4 inch fitting size suits common small-bore pipe and instrument connections
• Compact, low-profile design at approximately 0.06 pounds per unit

Compatibility

Designed as an OEM-style replacement or new-install fitting for standard 1/4 inch female NPT threaded pipe connections in plumbing, HVAC hydronic, and industrial piping systems.

Installation Notes

Installation is performed by licensed plumbers or qualified pipefitters in accordance with applicable codes such as the IPC and IFGC. Depressurize and drain the affected line segment before removing or installing any threaded plug. Apply thread sealant or PTFE tape to the MNPT threads before seating to ensure a leak-free seal. Use a properly sized wrench on the square head; do not use pipe wrenches or pliers that may deform the head or damage the threads.