Push-in fittings are unique in that they provide a very easy installation and are less bulky than compression fittings for low clearance situations. Union tees are a three sided connector with tube connectors on all sides and have either all the same size connectors or alternating sizes depending on the application. They are designed, to resist pull-out, are highly corrosion resistant, and have a maximum working pressure of up to 2,800 PSI.