What type of mechanical joint do ductile iron pipe joints with rubber gasket push belong to?

Ductile iron pipe joints with rubber gasket push belong to the mechanical joint (MJ) type because they utilize a rubber gasket to create a seal between two pipe ends. This type of joint is designed to allow for flexibility and some angular deflection between the pipes, while the rubber gasket provides a watertight seal. The MJ type joints are commonly used in waterworks applications because they are easier to install, help accommodate ground movement, and provide a reliable connection that can be disassembled if maintenance is required. The other joint types mentioned are not characterized by the use of rubber gaskets for sealing, focusing instead on different connection methods which might not provide the same level of flexibility and adaptability as the MJ type.