A main valve for a straightway deluge valve includes a valve body (1), a valve cover (2), a diaphragm (3), a drawing piston (4), a diaphragm pressure plate (5), a drawing link (6), a valve body link (7), a valve plate link (8), a rotatable lip and a mounting hole cover (13). A piston guide is provided at a side part of the valve body (1). The drawing piston (4) is provided slidably in the piston guide along a left-right direction. When the drawing piston (4) slides along the piston guide, the rotatable lip can contact with or separate from the inner sealing end surface. The main valve for drawing the straightway deluge valve, after the valve plate (9) is opened, enables the flow passage to be close to a straightway passage, thereby reducing flow loss.

Actuator stem and rod end bearings having locking mechanisms are described. An example apparatus for use with a control valve actuator includes a rod end bearing having a bearing retainer and a shaft portion extending from the bearing retainer, where the shaft portion defines a first face. An actuator stem has a first end to be operatively coupled to a diaphragm plate of the control valve actuator and a second end to be coupled to the rod end bearing, where the second end defines a second face. The first face engages the second face to provide a lock that prevents rotation of the actuator stem relative to the rod end bearing when the actuator stem is rotated in a first direction.

A system and method for regulating a flow of a fluid, wherein the system comprises a regulating device and a central axis, wherein the regulating device is adapted to establish at least one through-passage opening for the fluid, wherein each time a through-passage opening is situated between two transport ducts for the fluid, wherein a normal vector of a cross sectional surface of the at least one through-passage opening is oriented parallel to the axis, wherein a size of the cross-sectional surface is adjusted in dependence on the rotary speed of the regulating device turning about the central axis.

A system and method for regulating a flow of a fluid, wherein the system comprises a regulating device and a central axis, wherein the regulating device is adapted to establish at least one through-passage opening for the fluid, wherein a normal vector of a cross sectional area of the at least one through-passage opening is oriented parallel to the axis, wherein a size of the cross-sectional area is adjusted in dependence on the rotary speed of the regulating device turning about the central axis.