Installing a fluid regulator in a fluid distribution system by: determining the position and orientation of the fluid regulator in the fluid distribution system; determining if a first opening and/or a second opening in the body of the regulator, are accessible with the fluid regulator in the determined position and orientation; installing the slam-shut device in the first opening, if accessible, and securing a plate over the second opening; and installing the fluid regulator in the fluid distribution system. The first and second openings are dimensioned such that the slam-shut device can be secured at least partially within the first opening in a first configuration and can be secured at least partially within the second opening in a second configuration.