Subplated valves require a mounting base. This mounting base is pre-plumbed to existing control lines. Due to the nature of the plumbing lines fixed to a mounting base, replacing subplate mounted valves is rapid and quick. All port connections, excluding "External Pilot" or "Pilot Return" ports, if used, are made through O-ring sealed holes in the base of the valve through a subplate. O-ring seals and mounting screws are furnished with each subplate valve. Because the connections to a base mount can be of any size and configuration, subplate mounted valves are assigned a designation derived from a basic valve body size. A 3P size subplate valve will have the same flow characteristics as a 3/8" NPTF side ported valve body. Consult factory on the possibility of routing external pilot or pilot return sources through the subplate.