If you have a compression fitting that you need to block off either temporarily or permanently, these teflon PTFE plugs are just what you need. To be
Stainless Steel Pipe Fittings/Plug, MISUMI
Generic Brass Flare 1/4 OD Plug, Brass Flare Tube Fitting (Pack of 10) : : Tools & Home Improvement
Compression Tube Fitting 1/2 OD Tube Plug End Cap Stainless Steel 316
316 Stainless Steel Tube Fittings Male Connector - 316L stainless steel (inox 316) two ferrules tube fittings male connector, 316 stainless steel(inox 316) double ferrules compression tube fitting male connector, 316 stainless
LWP Pipe Plug / S.S. Stainless Steel Size 3/4 Inch 316 Compression fittings / Tubing connections / Hex Plug Solid Plug / Size range from 1/8 to 2 / SS 304/304L ,SS 316/316S Plug Solid Plug -SK-LOK
316 Stainless Steel Cap for 1/2 in. OD Tubing, Caps and Plugs, Tube Fittings and Adapters, Fittings, All Products
1/4 Tube Od Compression Fitting Sealing Plug for Copper Tubing Water Oil Air
Tube Compression Fittings
Double Ferrule Compression Fittings - FAV Fittings and Valves