Abstract: In the preferred and illustrated embodiment, a multivalve manifold control and interlock system is set forth. The multivalve manifold comprises three valves arranged within a valve body, wherein valve stems with optional handles are located above the valve body to be gripped and rotated. The valve body encloses three ball or plug valves. They are switched by 90.degree. rotation. Each stem supports a circular disk, and the three stems are equipped with three circular disks which interlock. Certain arcuate notches are cut in the circular disks. The arrangement of the notches limits the sequence in which the valves are opened and closed. Moreover, opening and closing is constrained to the sequence required for safe operation of the multivalve manifold. Further, a lock bar is incorporated, and is profiled to fit with the valve stems for locking.

Abstract: A pressure transmitter manifold having a block with an inlet in communication with a pair of outlets, valve means controlling communication between the inlet and said outlets, valve controlled bleed and test connections in communication with said outlets and means for supporting said manifold block in a preselected position.

Abstract: A support structure for a differential pressure transmitter and its valve manifold including an angle plate supported from a pipe, fasteners securing the valve manifold to the angle plate and fasteners securing the transmitter to the valve manifold and the method of servicing the transmitter by removing it from the valve manifold without disconnecting the support structure.