Valve position controller

• US 5,654,885 A
• Filed: 03/28/1995
• Issued: 08/05/1997
• Est. Priority Date: 03/28/1995
• Status: Expired due to Term

• Current Assignee: Mueller International LLC (Mueller Water Products Incorporated)
• Original Assignee: Virginia Valve Company Corporation
• Inventors: Puckett, Dwayne M., Mayhew, John
• Primary Examiner(s): Elmore, Reba I.
• Assistant Examiner(s): OAKES, BRIAN
• Application Number:
  US08/411,889
• Time in Patent Office: 861 Days
• Field of Search: 364/181, 364/180, 364/138, 364/141, 364/509, 364/510, 137/1, 137/2, 137/565, 137/566, 137/567, 137/569, 137/487.5, 137/900, 60/394, 251/129.03
• US Class Current: 700/282
• CPC Class Codes: F15B 20/00 Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
• CPC Class Codes: F15B 9/09 with electrical control means
• CPC Class Codes: G05B 11/50 in which the output signal represents a continuous function of the deviation from the desired value, i.e. continuous controllers
• CPC Class Codes: G05B 2219/41311 Pilot valve with feedback of position
• CPC Class Codes: G05B 2219/42205 With potentiometer
• CPC Class Codes: G05B 2219/45006 Valves
• CPC Class Codes: G05B 2219/50042 Return to origin, reference point, zero point, homing
• CPC Class Codes: G05D 16/2053 the plurality of throttling means comprising only a first throttling means acting on a higher pressure and a second throttling means acting on a lower pressure, e.g. the atmosphere
• CPC Class Codes: G05D 16/2097 using pistons within the main valve
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve

Abstract

A valve position controller (10) for controlling the position of an industrial-valve element (29, 29'"'"') includes a check valve (72, 74) in each of closing and opening pressurized-fluid input lines (68, 70) for respectively leading pressurized fluids from a pressurized source (30) to closing and opening solenoid actuating valves (106, 104) via a common input fork (62). The valve position controller can be changed between a fail-in-place" mode, and a "fail-closed" mode by interchanging input and exhaust lines (68, 88) to an opening actuating valve (64) and reversing electrical operation of a solenoid (104) of the opening actuating valve. A needle valve (94) in a common exhaust line allows speed of the system to be optimized for a set resolution. Locking actuating valves (108, 110) are respectively between the closing and opening actuating valves and a motivator (34, 36) to lock the industrial valve element (29'"'"', 29) in position when close and open manual switches (48, 50) are not activated and an auto/manual switch (46) is in a "manual" position.

Claims

1. A valve position controller for controlling the position of an industrial valve element of an industrial valve apparatus to thereby achieve a desired flow of conduit fluid through a conduit as measured by a fluid-condition transducer and monitored by a process controller, said industrial valve apparatus being of a type comprising a fluid-actuated motivator attached to said industrial valve element for moving said industrial valve element and a position-sensing transducer for producing an analog electrical signal corresponding to an actual position of the industrial valve element, said valve position controller comprising:

closing and opening actuating valves for respectively receiving pressurized actuating fluid from a pressure source and controlling flow of said actuating fluid to and from said motivator to thereby move said industrial valve element;

an electrical-signal comparator for receiving and comparing an electrical actual-position signal from said position-sensing transducer with an electrical desired-position signal from said process controller and producing control signals in response to a difference between said actual-position and desired-position signals;

closing and opening solenoids respectively coupled to said closing and opening actuating valves for receiving said control signals and respectively moving said closing and opening valves to positions for allowing flow of pressurized actuating fluid to and from said motivator for opening and closing said industrial valve element;

biasing means for biasing each of said closing and opening actuating valves to a home position when its respective closing and opening solenoid is not energized;

closing and opening input lines for respectively leading pressurized fluid from said pressurized source to each of said closing and opening actuating valves;

closing and opening exhaust lines leading exhausted pressurized fluid from said respective closing and opening actuating valves;

wherein said closing and opening actuating valves are biased to move to said home position upon loss of power; and

,

wherein the respective closing and opening input line can be interchanged with the respective closing and opening exhaust line of at least one of the closing and opening actuating valves so that upon a loss of power the fail safe position of the motivator depends upon the configuration of the input and exhaust lines of the at least one closing and opening actuating valve; and

,

wherein is further included an electrical switch for reversing operation of the solenoid of the at least one of the closing and opening actuating valves upon operation of the electrical switch so that the at least one of the closing and opening actuating valves will function to close and open the industrial valve element in response to the control signals of the comparator when said input and exhaust lines of said at least one of the closing and opening actuating valves are interchanged.

2. A valve position controller as in claim 1 wherein said biasing means biases said closing and opening actuating valves to allow pressurized fluid flow to said motivator from both said closing and opening input lines upon a failure of power so that said motivator fails in place.

3. A valve position controller as in claim 2 wherein is further included a mode switch for switching the valve position controller into a manual mode in which said control signals from said comparator are deactivated and manually operated close and open switches are energized so that said closing and opening solenoids can be manually energized for closing and opening the industrial valve element by said close and open switches.

4. A valve position controller as in claim 3 wherein is further included closing and opening locking valves respectively positioned between each of said closing and opening actuating valves and said motivator when said mode switch is in the manual-mode position and neither of said manually-operated close and open switches is activated to thereby lock the motivator in place.

5. A valve position controller as in claim 4 wherein:

closing and opening exhaust lines leading exhausted pressurized fluid from said respective closing and opening actuating valves are commonly joined at a fork and then exhausted through a common exhaust line; and

is further included a gradually adjusting flow valve on said common exhaust line for finely adjusting flow through said common exhaust line.

6. A valve position controller as in claim 3 wherein:

closing and opening exhaust lines leading exhausted pressurized fluid from said respective closing and opening actuating valves are commonly joined at a fork and then exhausted through a common exhaust line; and

is further included a gradually adjusting flow valve on said common exhaust line for finely adjusting flow through said common exhaust line.

7. A valve position controller as in claim 2 wherein:

closing and opening exhaust lines leading exhausted pressurized fluid from said respective closing and opening actuating valves are commonly joined at a fork and then exhausted through a common exhaust line; and

is further included a gradually adjusting flow valve on said common exhaust line for finely adjusting flow through said common exhaust line.

8. A valve position controller as in claim 1 wherein is further included a mode switch for switching the valve position controller into a manual mode in which said control signals from said comparator are deactivated and manually operated close and open switches are energized so that said closing and opening solenoids can be manually energized for closing and opening the industrial valve element by said close and open switches.

9. A valve position controller as in claim 8 wherein is further included closing and opening locking valves respectively positioned between each of said closing and opening actuating valves and said motivator when said mode switch is in the manual-mode position and neither of said manually-operated close and open switches is activated to thereby lock the motivator in place.

10. A valve position controller as in claim 9 wherein:

closing and opening exhaust lines leading exhausted pressurized fluid from said respective closing and opening actuating valves are commonly joined at a fork and then exhausted through a common exhaust line; and

is further included a gradually adjusting flow valve on said common exhaust line for finely adjusting flow through said common exhaust line.

11. A valve position controller as in claim 1 wherein:

closing and opening exhaust lines leading exhausted pressurized fluid from said respective closing and opening actuating valves are commonly joined at a fork and then exhausted through a common exhaust line; and

is further included a gradually adjusting flow valve on said common exhaust line for finely adjusting flow through said common exhaust line.

12. A valve position controller for controlling the position of an industrial valve element of an industrial valve apparatus to thereby achieve a desired flow of conduit fluid through a conduit as measured by a fluid-condition transducer and monitored by a process controller, said industrial valve apparatus being of a type comprising a fluid-actuated motivator attached to said industrial valve element for moving said industrial valve element and a position-sensing transducer for producing an analog electrical signal corresponding to an actual position of the industrial valve element, said valve position controller comprising:

closing and opening actuating valves for respectively receiving pressurized actuating fluid from a pressure source and controlling flow of said actuating fluid to and from said motivator to thereby move said industrial valve element;

an electrical-signal comparator for use in an automatic mode for receiving and comparing an electrical actual-position signal from said position-sensing transducer with an electrical desired-position signal from said process controller and producing control signals in response to a difference between said actual-position and desired-position signals;

closing and opening solenoids respectively coupled to said closing and opening actuating valves for receiving said control signals and respectively moving said closing and opening valves to positions for allowing flow of pressurized actuating fluid to and from said motivator for opening and closing said industrial valve element;

wherein is further included a mode switch for switching the valve position controller from said automatic mode into a manual mode in which said control signals from said comparator are deactivated and manually operated close and open switches are energized so that said closing and opening solenoids can be manually energized for closing and opening the industrial valve element by said close and open switches; and

wherein is further included closing and opening locking valves respectively positioned between each of said closing and opening actuating valves and said motivator for closing to block actuating fluid flow to and from said motivator when said mode switch is in said manual-mode position and neither of said manually-operated close and open switches is activated but for opening to allow actuating fluid flow to and from said motivator when said mode switch is in said manual-mode position and either of said manually-operated closed and open switches is activated.

13. A valve position controller for controlling the position of an industrial valve element of an industrial valve apparatus to thereby achieve a desired flow of conduit fluid through a conduit as measured by a fluid-condition transducer and monitored by a process controller, said industrial valve apparatus being of a type comprising a fluid-actuated motivator attached to said industrial valve element for moving said industrial valve element and a position-sensing transducer for producing an analog electrical signal corresponding to an actual position of the industrial valve element, said valve position controller comprising:

closing and opening actuating valves for respectively receiving pressurized actuating fluid from a pressure source through respective closing and opening input lines and exhausting it through respective closing and opening exhaust lines to thereby control flow of said actuating fluid to and from said motivator and thereby move said industrial valve element;

an electrical-signal comparator for use in an automatic mode for receiving and comparing an electrical actual-position signal from said position-sensing transducer with an electrical desired-position signal from said process controller and producing control signals in response to a difference between said actual-position and desired-position signals;

closing and opening solenoids respectively coupled to said closing and opening actuating valves for receiving said control signals and respectively moving said closing and opening valves to positions for allowing flow of pressurized actuating fluid to and from said motivator for opening and closing said industrial valve element;

wherein is further included a mode switch for switching the valve position controller from said automatic mode into a manual mode in which said control signals from said comparator are deactivated and manually operated close and open switches are energized so that said closing and opening solenoids can be manually energized for closing and opening the industrial valve element by said close and open switches;

wherein is further included closing and opening locking valves respectively positioned between each of said closing and opening actuating valves and said motivator when said mode switch is in the manual-mode position and neither of said manually-operated close and open switches is activated to thereby lock the motivator in place;

wherein said closing and opening actuating valves are biased to move to a home position upon loss of power;

wherein said respective closing and opening input and exhaust lines of at least one of the closing and opening actuating valves can be interchanged so that upon a loss of power the fail safe position of the motivator depends upon the configuration of the input and exhaust lines of the at least one of the closing and opening actuating valves; and

,

wherein is further included an electrical switch for reversing operation of the solenoid of the at least one of the closing and opening actuating valves upon operation of the electrical switch so that the at least one of the closing and opening actuating valves will function properly to close and open the industrial valve element upon respective operation of the manually operated closing and opening switches in the manual mode and in response to the control signals of the comparator in the automatic mode when said input and exhaust lines of said at least one of the closing and opening actuating valves are interchanged.