Double ferrule tube fittings are the most common style of instrumentation fittings, and they can also be purchased in brass materials.
Brennan Industries, N2650-04-04-04-04-SS
Brennan's Instrumentation Tube Fittings provide leak-proof, torque-free seals at all tubing connections. Brennan's Double-Ferrule and Single-Ferrule
Connector - Straight, Compression Fittings, N2405 Series
316 Stainless Steel, Compression x MNPT, Bulkhead Male Connector
Brennan Industries Announces Release of New Instrumentation Valves
Brennan Industries Instrumentation Double Ferrule Tube
Quality tube fittings and adapters at Brennan Industries
Brennan Industries Instrumentation Double Ferrule Tube
Brennan Industries, Inc.
1/2 Tube O.D. x 1/2 FPT Female Connector, Double-Ferrule
Double Ferrule Tube Fittings at Brennan Industries