PolarSeal ACA couplings are for use with Gates PolarSeal air conditioning hose. ACA couplings are available in many of the most popular styles of aluminum couplings, with select styles available in zinc-plated steel. Available in various bend angles and common stem sizes -6, -8, -10, and -12. Utilize Gates PolarSeal Portable Crimper, or one of Gates bench top crimpers, to make crimped AC assemblies using ACA couplings and PolarSeal hose. The orifice tube filters and restricts high-pressure refrigerant in the liquid line and meters refrigerant flow as a low-pressure liquid. The tube should be replaced any time the air conditioning system is opened for service.