JB machines all access valves our Aurora, Illinois factory using the highest level of brass consisting of 65% copper and 35% zinc. This gives our brass fittings and access valves high tensile strength while resisting corrosion. Many import fittings use lower quality brass with lower copper content, resulting in higher failure rates. JB machines all of our valves to the strict guidelines of the AHRI to ensure proper sealing of the valve and core surfaces. Our access fittings have generous counter bores to allow for the removal of the core if the flare becomes damaged. All tees and crosses are tapped to receive and access core in all 1/4" SAE flare ends. All pipe connections have internal braze cups for dip tube applications. All valves are equipped with cap and one valve core (braze type, loosely assembled). Temperature range -40 degrees to +250 degrees Fahrenheit (-40 to 121.1 degrees Celsius). Valve core is stainless steel and brass for use with all refrigerants including R410A. Resistant to oils, alkalites, and diluted mineral acids.