Tank-installable switches for installation through a thief hatch port on a tank. In some embodiments, the switch may comprise a tubular body and a liquid level sensor. The liquid level sensor may include: a detector; a float in and moveable along a length of the lower end; and a rod connecting the float to the detector. The liquid level sensor may be configured to sense a liquid level relative to the lower end and further configured to generate a signal when at least a maximum selected liquid level is sensed.

A fluid level measurement system using a buoyant body includes a guide part installed in a direction perpendicular to the bottom surface of a fluid storage tank, and provided with a space in which a fluid can move therein; a buoyant body inserted into the guide part, and configured to float along the surface of the fluid inside the guide part; and a measurement part coupled to the top end of the guide part, and configured to measure the level of the surface of the fluid inside the fluid storage tank by transmitting a signal toward the buoyant body in the inner space of the guide part and then receiving a signal reflected from the buoyant body.

A tank fill control apparatus comprising: a tank-installed switch, including: a tubular body including an upper end, a lower end, and an annular mounting flange on an outer surface between the upper end and the lower end; a liquid level sensor including a detector, a float in and moveable along a length of the lower end and a rod connecting the float to the detector, the liquid level sensor configured to sense a liquid level relative to the lower end and further configured to generate a signal when at least a maximum selected liquid level is sensed; and a control unit in communication with the tank-installed switch including: a liquid level monitoring function for receiving the signal from the liquid level sensor; and a control function for generating at least one of (i) an alert signal indicating that the maximum selected liquid level is sensed and (ii) a valve control to modify a fill operation from a tank fill system.

A system for monitoring an annular fluid level may include a floating element disposed on a surface of a drilling fluid within an annulus of the well, during mud cap drilling operations. The system may also include an antenna disposed above the floating element. The antenna may be configured to transmit a first signal to the floating element, and to receive a second signal from the floating element in response to the first signal. The system may also include a processor configured to determine a time value that measures a time between a transmittal, by the antenna, of the first signal and a receipt, by the antenna, of the second signal. The processor may also determine a state of a drilling fluid level within the annulus based on the time value, and update a drilling program for the well based on the state of the drilling fluid level.

A fuel tank has a tank body, a post, a first resistor, and a second resistor, a floating body, a detecting part, and a guiding part. The tank body stores fuel. The post is formed in a tubular shape, is formed with a flow port, and is joined to the bottom wall and the top wall. The first resistor and the second resistor are provided inside the post and extend in a height direction. The floating body is provided with a conductor, is formed with guided parts, and floats on the fuel inside the post. The detecting part energizes the first resistor, the conductor, and the second resistor to detect the position of the floating body in the height direction. The guiding part is provided on the post to guide the guided parts in the height direction.

A fuel tank has a tank body, a post, a first resistor, and a second resistor, a floating body, a detecting part, and a guiding part. The tank body stores fuel. The post is formed in a tubular shape, is formed with a flow port, and is joined to the bottom wall and the top wall. The first resistor and the second resistor are provided inside the post and extend in a height direction. The floating body is provided with a conductor, is formed with guided parts, and floats on the fuel inside the post. The detecting part energizes the first resistor, the conductor, and the second resistor to detect the position of the floating body in the height direction. The guiding part is provided on the post to guide the guided parts in the height direction.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A fluid tank system comprises a fluid container that includes a sensor opening in a fluid container wall defined by a rim, and a fluid level sensor comprising a radial flange on a proximate end of a longitudinally extending electronics stem that includes a distal end. The distal end of the electronic stem is inserted into the fluid container via the sensor opening and the radial flange seats on the rim. The distal end of the electronics stem is guided via a first radial support and a second radial support to a seat that is located coaxial with the sensor opening, where the first and second radial supports are longitudinally separated and radially spaced apart to allow the electronics stem to longitudinally pass between the first and second radial supports until the flange seats on the rim ensuring that the distal end of the electronic stem is longitudinally positioned adjacent to the seat.

A fluid tank system comprises a fluid container that includes a sensor opening in a fluid container wall defined by a rim, and a fluid level sensor comprising a radial flange on a proximate end of a longitudinally extending electronics stem that includes a distal end. The distal end of the electronic stem is inserted into the fluid container via the sensor opening and the radial flange seats on the rim. The distal end of the electronics stem is guided via a first radial support and a second radial support to a seat that is located coaxial with the sensor opening, where the first and second radial supports are longitudinally separated and radially spaced apart to allow the electronics stem to longitudinally pass between the first and second radial supports until the flange seats on the rim ensuring that the distal end of the electronic stem is longitudinally positioned adjacent to the seat.

A liquid level detecting device includes a sensor housing having a circular rotation recess, a circular holder which is fitted in the rotation recess and held rotatably by the sensor housing, a float arm, a float, a magnet, and a Hall element. The sensor housing has a lock groove and a pair of insertion holes. The holder has a pair of flanges which project in opposite directions from an outer circumferential surface of the holder and are engaged with the lock groove and prevented from coming off the rotation recess by setting the flanges opposed to the respective insertion holes, fitting the flanges into the rotation recess, and then rotating the flanges. The holder has a pair of support projections which come into contact with a bottom surface of the rotation recess.