Abstract: A testable back pressure valve can include a housing comprising a housing body. The valve can also include a valve seat coupled to the housing, where the valve seat includes a valve seat body having a first cavity and a second cavity, and where the valve seat further includes a first network of channels disposed in the valve seat body. The valve can further include a valve head movably disposed within the first cavity of the valve seat. The valve can also include a piston follower movably disposed within the second cavity of the valve seat, where the valve head is fixedly coupled to the piston follower. The valve can further include a travel piston movably disposed within the second cavity of the valve seat, where the travel piston is moveably coupled to the piston follower.

Abstract: A testable back pressure valve can include a body. The valve can also include a first flow regulating device movably disposed within a top end of the body, where the first flow regulating device is configured to move from a first default position to a first position based on first flow characteristics of a first fluid that flows into a top end of the body toward a bottom end of the body. The valve can further include a second flow regulating device movably disposed within the bottom end of the body. The valve can also include a network of channels disposed within the body between the first flow regulating device and the second flow regulating device.

Abstract: A system for monitoring a floating roof of a liquid storage tank and a method for use of the system are described. The system includes linear position measuring devices to determine the vertical location and orientation of the floating roof within the storage tank and one or more transmitters to relay such information to a monitoring, recording, or control device, or to a remote computer network location. Typically, three measuring devices are used, positioned at or near the top of the storage tank and generally equally spaced around the perimeter of the tank. The system and method are useful to monitor the position and inclination of a liquid storage tank floating roof, such as may be used in the petrochemical, chemical and other industries where such storage tanks are in use.

Abstract: A system for monitoring a floating roof of a liquid storage tank and a method for use of the system are described. The system includes linear position measuring devices to determine the vertical location and orientation of the floating roof within the storage tank and one or more transmitters to relay such information to a monitoring, recording, or control device, or to a remote computer network location. Typically, three measuring devices are used, positioned at or near the top of the storage tank and generally equally spaced around the perimeter of the tank. The system and method are useful to monitor the position and inclination of a liquid storage tank floating roof, such as may be used in the petrochemical, chemical and other industries where such storage tanks are in use.

Abstract: A testable back pressure valve can include a housing comprising a housing body. The valve can also include a valve seat coupled to the housing, where the valve seat includes a valve seat body having a first cavity and a second cavity, and where the valve seat further includes a first network of channels disposed in the valve seat body. The valve can further include a valve head movably disposed within the first cavity of the valve seat. The valve can also include a piston follower movably disposed within the second cavity of the valve seat, where the valve head is fixedly coupled to the piston follower. The valve can further include a travel piston movably disposed within the second cavity of the valve seat, where the travel piston is moveably coupled to the piston follower.

Abstract: A testable back pressure valve can include a body. The valve can also include a first flow regulating device movably disposed within a top end of the body, where the first flow regulating device is configured to move from a first default position to a first position based on first flow characteristics of a first fluid that flows into a top end of the body toward a bottom end of the body. The valve can further include a second flow regulating device movably disposed within the bottom end of the body. The valve can also include a network of channels disposed within the body between the first flow regulating device and the second flow regulating device.

Abstract: A gas lift valve system for a wellbore within a subterranean formation can include a power source that generates power, and a delivery system disposed within the wellbore and electrically coupled to the power source, where the delivery system delivers the power generated by the power source. The system can also include at least one gas lift valve assembly disposed within the wellbore and electrically coupled to the delivery system, where the at least one gas lift valve assembly receives the power from the delivery system, where at least one valve, when in a position other than a fully closed position, allows a control medium to flow from an inlet channel to an outlet channel, where the outlet channel empties into the cavity of the delivery system.