US 11,732,820 B2
Activating trip functions of a safety valve positioner by way of a control panel to achieve a safe state
Marwan Brama, Singapore (SG)
Assigned to FISHER CONTROLS INTERNATIONAL LLC, Marshalltown, IA (US)
Filed by FISHER CONTROLS INTERNATIONAL LLC, Marshalltown, IA (US)
Filed on Oct. 23, 2020, as Appl. No. 17/78,935.
Prior Publication US 2022/0128171 A1, Apr. 28, 2022
Int. Cl. F16K 37/00 (2006.01); G06F 3/0484 (2022.01); G05B 15/02 (2006.01)
CPC F16K 37/0083 (2013.01) [F16K 37/0041 (2013.01); G05B 15/02 (2013.01); G06F 3/0484 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A method for controlling safety valves comprising:
electrically coupling a control panel to a safety loop that communicatively couples a logic solver to a valve positioner for a safety valve, wherein the logic solver is configured to control the safety valve by varying a loop current on the safety loop to cause the valve positioner to adjust the safety valve to a desired position;
detecting, at the control panel, an actuation of a user interface element of the control panel that represents a trip command;
responding to the actuation by causing the control panel to manipulate the loop current on the safety loop such that the loop current enters a range;
detecting, at the valve positioner, the loop current entering the range;
responding, at the valve positioner, to detecting the loop current entering the range by initiating a trip function configured to drive the safety valve to a safe state; and
drawing, by the control panel, a level of current from the safety loop sufficient to power the control panel.