Methods and apparatus for bypassing a positioner in an active control loop

An actuator assembly, comprising:

• a pneumatic actuator;
• and
• a transfer station coupled to the pneumatic actuator, comprising:
• a single-body manifold configured to be used as a coupling interface between the pneumatic actuator and a valve positioner, the manifold defining first, second, and third flow paths and first and second ports coupled to the second flow path, the first port to be coupled to a first pressure gauge, the second port to be coupled to a second pressure gauge, the first flow path to couple a supply pressure and the valve positioner, the second flow path to couple the valve positioner and the pneumatic actuator, and the third flow path to couple the first flow path and the second flow path to bypass the valve positioner without disrupting a process loop including the valve positioner;
• first, second, and third fluid flow control devices positioned within the manifold to control the fluid flow through the respective ones of the first, second, and third flow paths, the second fluid flow control device positioned between the first and second ports;
• and
• a switching system communicatively coupled to the fluid flow control devices to determine respective positions of the fluid flow control devices.

A transfer station for use with a valve positioner, the transfer station comprising:

• a single-body manifold configured to be used as a coupling interface between the valve positioner and an actuator, the manifold defining first, second, and third flow paths, the first flow path comprising a first inlet and a first outlet, the first inlet to be coupled to a supply pressure, the first outlet to be coupled to the valve positioner, the first flow path enabling fluid to flow from the supply pressure to the valve positioner during a normal operation mode, the second flow path comprising a second inlet and a second outlet, the second inlet to be coupled to the valve positioner, the second outlet to be coupled to the actuator, the second flow path enabling fluid to flow from the valve positioner to the actuator during the normal operation mode, and the third flow path enabling fluid to flow between the first and second flow paths during a bypass operation mode that bypasses the valve positioner, the manifold further comprises a first port coupled to the second flow path and a second port coupled to the second flow path, the first port to be coupled to a first pressure gauge, the second port to be coupled to a second pressure gauge;
• a first fluid flow control device positioned within the manifold to control fluid flow between the supply pressure and the valve positioner during the normal operation mode;
• a second fluid flow control device positioned within the manifold to control fluid flow between the valve positioner and the actuator during the normal operation mode, the second fluid flow control device positioned between the first and second ports;
• a third fluid flow control device positioned within the manifold to control fluid flow between the first and second flow paths during the bypass operation mode, the bypass operation mode enabling manual control of a process loop while the valve positioner is not controlling the process loop;
• and
• a switching system communicatively coupled to the first, second, and third fluid flow control devices to determine respective positions of the first, second, and third fluid flow control devices based on the transfer station being in the normal operation mode or the bypass operation mode.