1/2 NPT Female Solid Brass Three Piece Pipe Union Fitting Adapter – compressor-source

Legines Brass Pipe Fitting, 1/2 NPTF Female x 1/2 NPTF Male Adapter (Pack of 5) : Industrial & Scientific

1/2 Male NPTF Hex Nipple Brass Straight Pipe Fitting 1200 PSI Maximum – compressor-source

1/4 NPT Extender Pipe Fitting 1-9/16 Long Solid Brass Pressure Gauge Adapter

Uenede 2PCS Solid Brass Bulkhead Fitting 1/2”Female x 3/4”Male Double Threaded Bulkhead Water Tank Connector : Industrial & Scientific

Air Compressor Fittings at

Water Source 1-1/2 in. Brass Male Insert Adapter MA150NL - The Home Depot

Pipe Fittings & Accessories – tagged Unions – compressor-source

Air Compressor Tank Port Fittings NPT 1/4 3/8 1/2'' Solid Brass Male Thread Water Drain Safety Valve Replacement Part - AliExpress

3/8 NPTF Female Union Tee Solid Brass Pipe Fitting T Joint Hose Conne – compressor-source

1/2 NPT Female Solid Brass Union Tee T Joint Pipe Hose Connector New 2-Pack 684659148254

1/2 Npt Female 3 Piece Union Coupling Brass Pipe Fitting Air Water Oil Gas Fuel