Abstract: A controller assembly is adapted for regulating at least one valve having a valve positioner. The controller assembly comprises a digital controller having a plurality of data inputs and data outputs and includes at least one proportional-integral-derivative (PID) controller operative to modulate the valve positioner in response to data received at the data inputs. The digital controller is configured to perform the following functions within a total time period of no greater than 10 ms: acquisition of data at the data inputs, processing of the data, and transmission of data from the data output in order to regulate the valve(s). The digital controller may include a quantity of at least sixteen digital inputs, at least sixteen digital outputs, at least eight analog inputs and at least eight analog outputs.

Abstract: A controller assembly is adapted for regulating at least one valve having a valve positioner. The controller assembly comprises a digital controller having a plurality of data inputs and data outputs and includes at least one proportional-integral-derivative (PID) controller operative to modulate the valve positioner in response to data received at the data inputs. The digital controller is configured to perform the following functions within a total time period of no greater than 10 ms: acquisition of data at the data inputs, processing of the data, and transmission of data from the data output in order to regulate the valve(s). The digital controller may include a quantity of at least sixteen digital inputs, at least sixteen digital outputs, at least eight analog inputs and at least eight analog outputs.

Abstract: An axial thrust balancing system for a centrifugal compressor, having improved safety characteristics, the centrifugal compressor comprising a rotor having impellers adjacent to each other and connected by a shaft, the rotor rotating in a stator, the centrifugal compressor additionally including a balancing piston, a balancing line being provided between an intake of a first compression stage and an area downstream of the balancing piston; this system comprises an intake mechanical gas seal around the shaft upstream of the first compression stage and an outlet mechanical gas seal downstream of the balancing piston, the balancing line being closable by blocking elements.

Abstract: An axial thrust balancing system (10) for a centrifugal compressor (12), having improved safety characteristics, the centrifugal compressor (12) comprising a rotor (14) having impellers (16) adjacent to each other and connected by a shaft (18), the rotor (14) rotating in a stator (20), the centrifugal compressor (12) additionally including a balancing piston (22), a balancing line (24) being provided between an intake of a first compression stage and an area downstream of the balancing piston (22); this system (10) comprises an intake mechanical gas seal (26) around the shaft (18) upstream of the first compression stage and an outlet mechanical gas seal (28) downstream of the balancing piston (22), the balancing line (24) being closable by means of blocking elements (32).