Valve actuator and method

A valve actuator for a valve, said actuator comprising:

• a hydraulic actuator housing;
• a hydraulic piston slidably mountable within said hydraulic actuator housing responsively to hydraulic pressure, said hydraulic piston being moveable to a first position for closing said valve and to a second position for opening said valve;
• a piston indicator for indicating whether said hydraulic piston is in said first position or said second position;
• and
• a hydraulic cylinder within said hydraulic actuator housing, said hydraulic piston being moveable within said hydraulic cylinder hydraulic between said first position and said second position, said piston indicator being mounted to said hydraulic actuator housing externally with respect to said hydraulic cylinder.

A valve actuator for a valve, said actuator comprising:

• a hydraulic actuator housing;
• a hydraulic piston slidably mountable within said hydraulic actuator housing responsively to hydraulic pressure, said hydraulic piston being moveable to a first position for closing said valve and to a second position for opening said valve;
• an override member for overriding said hydraulic pressure to control said position of said hydraulic piston, said override member being moveable a first distance between an override engaged position and an override disengaged position;
• and
• an override indicator, said override indicator being moveable a second distance between an override engaged indication position and an override disengaged indication position, said first distance being greater than said second distance.

A valve actuator for a valve, said actuator comprising:

• a hydraulic actuator housing attachable to said valve;
• a hydraulic piston slidably mountable within said hydraulic housing responsively to hydraulic pressure, said hydraulic piston being moveable to a first position for closing said valve and to a second position for opening said valve;
• a cylinder member defining therein a piston chamber, said hydraulic piston being mounted for movement within said piston chamber, said cylinder member defining a first hydraulic fluid port into said piston chamber on a first side of said piston and a second hydraulic fluid port into said piston chamber on a second side of said piston;
• a plurality of seals for limiting movement of hydraulic fluid within said hydraulic actuator housing to said piston chamber and said first hydraulic fluid port and said second hydraulic fluid port;
• a manual override assembly for manually operating said hydraulic piston;
• and
• a return spring within said hydraulic actuator housing in surrounding relationship to said cylinder member, said return spring being isolated from said hydraulic fluid by said plurality of seals.

A valve actuator for use with a valve, said valve having a valve body with a valve body cavity therein, a valve body cavity seal for sealing said valve body cavity, said actuator comprising:

• a hydraulic actuator housing attachable to said valve;
• a hydraulic piston sidably mountable within said hydraulic actuator housing responsively to hydraulic pressure;
• an actuator shaft assembly connected with respect to said hydraulic piston and extending into said valve body cavity for operating said valve such that said hydraulic piston is moveable to a first position for closing said valve and to a second position for opening said valve;
• and
• a first t-slot connection on said actuator shaft assembly for interconnection with said hydraulic piston and a second t-slot connection on said actuator shaft assembly for interconnection with said valve.

A valve actuator for use with a valve, said valve having a valve body with a valve body cavity therein, a valve body cavity seal for sealing said valve body cavity, said actuator comprising:

• a hydraulic actuator housing attachable to said valve;
• a hydraulic piston slidably mountable within said hydraulic actuator housing responsively to hydraulic pressure;
• an actuator shaft assembly connected with respect to said hydraulic piston and extending into said valve body cavity for operating said valve such that said hydraulic piston is moveable to a first position for closing said valve and to a second position for opening said valve;
• and
• a first valve member mounted to said actuator shaft assembly for movement with said actuator shaft;
• and
• a first seat in surrounding relationship to said actuator shaft, said first valve member engaging said first seat for sealing around said actuator shaft.

A method for preventing leakage between an actuator and a gate valve wherein an actuator shaft is reciprocally moveable for operating said gate valve, said method comprising:

• mounting a first valve member in surrounding relationship to said actuator shaft for movement therewith;
• providing a first seat in surrounding relationship to said actuator stem;
• and
• engaging said first valve member with said first seat when said actuator shafts moves to a first position.

A method for preventing leakage between an actuator and a gate valve wherein an actuator shaft is reciprocally moveable for operating said gate valve, said method comprising:

• mounting a packing body in surrounding relationship to said actuator shaft;
• providing a recess in a metallic housing for receiving said packing body;
• mounting a packing body seal between said recess and said packing body;
• mounting one or more seals around said actuator shaft between said packing body seal and said gate valve for sealing leakage along said actuator shaft;
• and
• providing one or more relief valves in communication with said recess.

A valve actuator for a valve, said actuator comprising:

• a hydraulic actuator housing attachable to said valve;
• a hydraulic piston slidably mountable within said hydraulic housing responsively to hydraulic fluid, said hydraulic piston being moveable to a first position for closing said valve and to a second position for opening said valve;
• a return spring within said hydraulic actuator housing;
• a moveable member within said hydraulic actuator housing with a surface for engaging one end of said return spring;
• a bottom mounting plate with a lip for engaging an opposite end of said return spring;
• one or more pre-load bolts, said pre-load bolts being secured to said moveable member and said bottom mounting plate to thereby limit expansion of said return spring such that said return spring is pre-loaded with tension.

A method for assembly a valve actuator for a valve, said method comprising:

• providing a hydraulic actuator housing attachable to said valve;
• providing a return spring for placement within said hydraulic actuator housing;
• engaging one end of said return spring with a first lip member;
• engaging an opposite end of said return spring with a second lip member;
• securing said first lip member and said second lip member together to thereby compress said return spring;
• selectively adjusting tension on said return spring by adjusting a maximum length between said first lip and second lip;
• and
• installing said first lip member, said second lip member, and said return spring into said hydraulic housing as a unit.