Merit Brass 3687D-02 Pipe Union 1/8 Inch 316 Ss Fnpt

Product Description

The MERIT BRASS 3687D-02 is a 1/8 inch threaded pipe union rated for 3,000 psi service in 316 and 316L stainless steel construction. A union fitting allows a pipe run to be disconnected without disturbing the rest of the system, making it essential for serviceability in pressurized lines. The female NPT connections on both ends thread directly onto standard NPT pipe. The 316/316L dual-grade stainless material provides strong resistance to corrosion, including chlorides and aggressive process fluids. Plumbers, pipefitters, and industrial service technicians install this fitting in high-pressure piping systems where future disassembly access is required.

This union is suited for use in residential and commercial plumbing, process piping, instrumentation lines, and fluid handling applications where stainless steel is specified for corrosion resistance. The 3,000 psi pressure rating supports demanding service conditions common in hydraulic, steam, chemical feed, and compressed gas installations. Its compact 1/8 inch size makes it a common choice for instrument tap lines, gauge connections, and small-bore process piping.

Key Features

• 3,000 psi pressure rating supports high-pressure piping applications
• 316 and 316L stainless steel construction for superior corrosion resistance
• FNPT x FNPT end connections for standard NPT threaded pipe assembly
• 1/8 inch fitting size for small-bore and instrument line installations
• Union design allows in-line disconnection without disturbing surrounding pipe

Compatibility

Designed as a standard-thread OEM-style replacement or new-install union fitting for 1/8 inch NPT threaded pipe systems requiring 316 or 316L stainless steel construction.

Installation Notes

Installation of pipe unions is typically performed by licensed plumbers or pipefitters. Depressurize and drain the system fully before disconnecting or installing any union fitting. Apply thread sealant or PTFE tape rated for the service fluid and pressure before making up NPT connections. Tighten to snug-plus-turns appropriate for the fitting size per standard pipefitting practice; do not overtighten stainless steel NPT threads, as galling can damage the connection.