Double ferrule or Single ferrule hydraulic compression fittings?

Brennan Industries N0304 Double Ferrule Tube Fittings

SS Double Ferrule Tube Fittings, Size: 1/4 inch-1 inch at Rs 80

STAINLESS STEEL SS 316 Double Ferrule Fittings, For

Single-Ferrule or Double-Ferrule – Which One to Use?

Ferrule Fittings - RFS Hydraulics

This is the structure of a typical hydraulic tube fitting

Why do people prefer the Double ring fitting or Single Ring?

Double Ferrule Compression Fittings • Projectmaterials

Size: Tube OD 3/8; Male Dia : NPT1/4; Ferrule Mini Inner Dia : 3/8 . Material: 304 stainless steel , corrosion resistant ductility at high

Beduan 304 Stainless Steel Compression Fitting Ferrule, 3/8 Tube OD x 1/4 NPT Male, Straight Adapter Connect with Double Ferrules (Pack of 5)