Valve assembly and related arrangements

1. A system comprising:

a valve assembly comprising

an inlet port, an outlet port, and a fluid conduit fluidly connecting the inlet and outlet ports for allowing fluid to pass therebetween,

a stop valve having a spindle that is centrally mounted within the valve assembly and a valve head mounted on the spindle, the stop valve spindle being configured, arranged, and operable to move the stop valve head between an open position, in which the inlet port is in communication with the outlet port, and a closed position, in which the outlet port is isolated from the inlet port, and

a control valve having at least one spindle that is eccentrically mounted within the valve assembly and a valve head mounted on the at least one control valve spindle, the at least one control valve spindle being configured, arranged, and operable to move the control valve head for graduated flow control of fluid passing along the fluid conduit, the stop valve head being nested within the control valve head when the stop valve is in the open position; and

a controller configured and arranged to monitor conditions external to, internal to, or both, the valve assembly and to control the position of the valves within the assembly according to said conditions.

2. A system according to claim 1 , wherein the at least one control valve spindle is eccentrically mounted with respect to the control valve head.

3. A system according to claim 1 , wherein the at least one spindle of the control valve comprises a plurality of spindles on which the control valve is mounted.

4. A system according to claim 1 , wherein the fluid conduit is configured and arranged to turn the fluid though 90 degrees of arc between the inlet port and the outlet port.

5. A system according to claim 1 , wherein the stop valve head obturates the outlet port when the stop valve head is in the closed position.

6. A system according to claim 1 , wherein the stop valve head, when not in the closed position, is configured and arranged to assist the conduit in deflecting the steam flow though a predetermined angle.

7. A system according to claim 1 , further comprising:

a fluid-tight gland component; and

wherein the stop valve spindle and the control valve at least one spindle sealingly pass though and are supported by the fluid-tight gland component.

8. A system according to claim 1 , further comprising:

a stop valve actuator configured and arranged to control the stop valve.

9. A system according to claim 8 , wherein which the stop valve actuator includes biasing means for closing the stop valve in the event of a failure of the stop valve actuator.

10. A turbine system comprising:

a steam generator, a steam turbine, and a fluid conduit fluidly connecting the generator and the turbine for transferring steam from the steam generator to the steam turbine; and

a valve assembly configured and arranged to control steam flow though the fluid conduit, the valve assembly comprising

an inlet port, an outlet port, and a fluid conduit fluidly connecting the inlet and outlet ports for allowing fluid to pass therebetween,

a stop valve having a spindle that is centrally mounted within the valve assembly and a valve head mounted on the spindle, the stop valve spindle being configured, arranged, and operable to move the stop valve head between an open position, in which the inlet port is in communication with the outlet port, and a closed position, in which the outlet port is isolated from the inlet port, and

a control valve having at least one spindle that is eccentrically mounted within the valve assembly and a valve head mounted on the at least one control valve spindle, the at least one control valve spindle being configured, arranged, and operable to move the control valve head for graduated flow control of fluid passing along the fluid conduit, the stop valve head being nested within the control valve head when the stop valve is in the open position.

11. A turbine system according to claim 10 , further comprising:

a controller configured and arranged to monitor conditions external to, internal to, or both, the valve assembly and to control the position of the valves within the assembly according to said conditions.

12. A turbine system according to claim 10 , wherein the at least one control valve spindle is eccentrically mounted with respect to the control valve head.

13. A turbine system according to claim 10 , wherein the at least one spindle of the control valve comprises a plurality of spindles on which the control valve is mounted.

14. A turbine system according to claim 10 , wherein the fluid conduit is configured and arranged to turn the fluid though 90 degrees of arc between the inlet port and the outlet port.

15. A turbine system according to claim 10 , wherein the stop valve head obturates the outlet port when the stop valve head is in the closed position.

16. A turbine system according to claim 10 , wherein the stop valve head, when not in the closed position, is configured and arranged to assist the conduit in deflecting the steam flow though a predetermined angle.

17. A turbine system according to claim 10 , further comprising:

a fluid-tight gland component; and

wherein the stop valve spindle and the control valve at least one spindle sealingly pass though and are supported by the fluid-tight gland component.

18. A turbine system according to claim 10 , further comprising:

a stop valve actuator configured and arranged to control the stop valve.

19. A turbine system according to claim 18 , wherein which the stop valve actuator includes biasing means for closing the stop valve in the event of a failure of the stop valve actuator.