1/4 inch Stainless Steel Union Female x Female

1/4 inch Stainless Steel Union – Machined for High-Integrity Line Connections

The 1/4 inch Stainless Steel Union is designed for joining two sections of threaded pipe or tubing where routine disassembly or alignment is required. Fabricated from corrosion-resistant 304 stainless steel, it provides a strong, reusable connection ideal for high-performance piping systems involving fluids, gases, or steam under moderate pressure and temperature ranges.

This union features female National Pipe Taper (NPT) threads on both ends, precision-machined to ensure consistent thread engagement, minimize galling, and support secure sealing with appropriate sealants. Its union nut enables straightforward field disconnection and reassembly without disturbing the adjoining pipe runs, making it well-suited for systems requiring periodic maintenance or alignment adjustments.

Key Performance Features

• ✅ Material Composition: Constructed from 304 stainless steel for high resistance to oxidation, corrosion, and thermal degradation in demanding service conditions.
• ✅ Threaded Union Design: Removable nut with internal cone seat enables full pipe separation without rotation, simplifying installation in fixed piping layouts.
• ✅ Precision NPT Threads: Female x Female configuration with tapered threads for improved mechanical seal and alignment with standard pipe components.
• ✅ Field Serviceability: Allows disassembly and resealing for inspection, cleaning, or replacement without disturbing surrounding joints.

Technical Specifications

• Nominal Size: 1/4 inch
• Connection: FNPT x FNPT (Female National Pipe Taper Thread)
• Material: Type 304 Stainless Steel
• Pressure Rating: Dependent on pipe schedule and temperature; consult ASME B31.3 or manufacturer data for exact limits
• Seal Mechanism: Metal-to-metal seating surface with union nut for axial compression

Installation Considerations

Apply PTFE tape or a compatible thread sealant to the NPT threads to ensure a leak-tight seal under pressure. Avoid over-torqueing to preserve thread integrity, especially in multi-metal systems. Alignment of the union faces must be maintained during tightening to avoid uneven compression of the sealing surfaces. Suitable for use in pressure-rated, closed-loop, or inspection-ready systems.

Application Range

Common in process piping, mechanical utility systems, control skids, and HVAC infrastructure. Particularly effective in installations requiring periodic component replacement, such as pump outlets, filter housings, or instrument access points where space constraints prevent full pipe rotation.

Compliance Note

This fitting conforms to lead-free regulations for potable water use under the Safe Drinking Water Act (SDWA) and meets material specifications outlined in ASTM A182 and ASME B16.39 for stainless threaded fittings, where applicable.