Help with size of copper tubing and compression fitting

PEX Compression Fittings: A Step-by-Step Guide

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Everbilt 1/2 in. OD Compression Brass Coupling Fitting 800939 - The Home Depot

61CL-10 Dixon Valve Brass Compression Fitting - Long Nut - 5/8 Tube S — HoseWarehouse

A Guide To Pipe Fittings and How To Use Them

Brass construction Moody Union Fits 2-inch iron pipes. 3-inch body length, with coupling washers and nuts Use for pipe repair Install over pipe, or

Brass Moody Compression Coupling with 2-Inch Iron Pipe Size

Poly Compression Fittings

Everything You Need To Know About Copper Pipe Fittings

Brass Compression Union 1/8 Tube Size

Brass, NPT x Compression, Brass Metric Compression Fitting - 791P91

Brass Compression Fittings and Adaptors

43282-2H Compression Fitting w/Breakaway Ferrule - BASO Gas Products LLC

How to Use Compression Fittings With Copper Pipe

What size of compression fitting do I need?