Push-in fittings are unique in that they provide a very easy installation and are less bulky than compression fittings for low clearance situations. Unions are made to connect two mating tubes. Composite push-in fittings are more cost effective and lighter than brass fittings while still maintaining the same working strength. They are designed to resist pull-out, are highly corrosion resistant, and have a maximum working pressure of up to 2,800 PSI.