Abstract: The invention discloses an enhanced gas extraction system based on dual-pulsation and acid fracturing permeability enhancement for a low-permeability coal seam, including an overpressure protection mechanism, a fracturing liquid delivery line, a gas extraction line, a mixing tank, a pressure control and monitoring mechanism and a frequency adjustment and monitoring mechanism. The invention further discloses an enhanced gas extraction method based on dual-pulsation and acid fracturing permeability enhancement for a low-permeability coal seam. The invention has the advantages of enhancing the connectivity between fracture-pore structures in coal, improving the permeability enhancement effect on a coal seam, and improving the gas extraction efficiency of the coal seam.

Abstract: The invention discloses an enhanced gas extraction system based on dual-pulsation and acid fracturing permeability enhancement for a low-permeability coal seam, including an overpressure protection mechanism, a fracturing liquid delivery line, a gas extraction line, a mixing tank, a pressure control and monitoring mechanism and a frequency adjustment and monitoring mechanism. The invention further discloses an enhanced gas extraction method based on dual-pulsation and acid fracturing permeability enhancement for a low-permeability coal seam. The invention has the advantages of enhancing the connectivity between fracture-pore structures in coal, improving the permeability enhancement effect on a coal seam, and improving the gas extraction efficiency of the coal seam.

Abstract: The invention discloses an enhanced extraction system based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam, including an ultrasonic excitation and acid fracturing integrated drilling device, an ultrasonic control box and a mixing tank. The invention further discloses an enhanced extraction method based on ultrasonic excitation and acid fracturing integrated permeability enhancement for a coal seam. The invention has the advantages of realizing intercoupling of ultrasonic excitation and acid fracturing, improving the pore structure of coal, enhancing the connectivity between pores and fractures, promoting gas desorption and improving gas extraction efficiency of coal seams.

Abstract: The invention discloses an ultrasonic excitation and nitrogen-injection pressurization coupling-enhanced gas extraction device and method for a low-gas coal seam. The ultrasonic excitation and nitrogen-injection pressurization coupling-enhanced gas extraction device includes a permeability-enhancement borehole and at least two exploration boreholes. An extraction sieve tube is mounted in each of the boreholes. An ultrasonic excitation and nitrogen-injection pressurization coupling integrated device is mounted in the extraction sieve tube in the permeability-enhancement borehole. The invention increases the permeability of coal seams and the gas flow driving force of the coal seams, thus efficiently solving the problem of a failure of gas extraction from low-gas coal seams.

Abstract: A spring-operated relief valve can include a main spring positioned between a bottom spring seat and a top spring seat. A seat assembly can include a valve seat, a seat retainer, and a spindle. The valve seat and the spindle can be received within an inner bore of the seat retainer and the spindle and the seat retainer can be threadably coupled. The valve seat can extend partially through the seat retainer to form a seal with a nozzle of the spring-operated relief valve and the spindle can engage the bottom spring seat to compress the main spring during a valve relief event.

Abstract: A spring-operated relief valve can include a main spring positioned between a bottom spring seat and a top spring seat. A seat assembly can include a valve seat, a seat retainer, and a spindle. The valve seat and the spindle can be received within an inner bore of the seat retainer and the spindle and the seat retainer can be threadably coupled. The valve seat can extend partially through the seat retainer to form a seal with a nozzle of the spring-operated relief valve and the spindle can engage the bottom spring seat to compress the main spring during a valve relief event.

Abstract: The disclosure provides automated update notifications. Embodiments include receiving, by a cloud provider, a request to manage updates for a computing device communicating with the cloud provider via a network. Embodiments include registering an agent at the computing device with the cloud provider as a recipient for an automated update notification based on configuration details of the computing device and detection of an update item related to an aspect of the configuration details. Embodiments include identifying, by the agent, the configuration details of the computing device, the configuration details comprising details of a hardware configuration of the computing device and a software configuration of the computing device. Embodiments include monitoring one or more databases for the update item. Embodiments include transmitting the automated update notification to the agent based on detection of the update item in the one or more databases.

Abstract: Example methods and systems for request handling with automatic scheduling are described. In one example, a computer system may receive, from multiple client devices, respective multiple requests that are generated and sent according to a first set of control parameters. Based on the multiple requests, request characteristic(s) may be monitored to determine whether an automatic scheduling condition is satisfied. In response to determination that the automatic scheduling condition is satisfied, the computer system may assign a second set of control parameters to the respective client devices and instruct the client devices to generate and send respective multiple subsequent requests according to the second set of control parameters to cause a modification of the request characteristic(s).

Abstract: A troubleshooting technique provides faster and more efficient troubleshooting of issues in a distributed system, such as a distributed storage system provided by a virtualized computing environment. The distributed system includes a plurality of hosts arranged in a cluster. The troubleshooting technique uses cluster-wide correlation analysis to identify potential causes of a particular issue in the distributed system, and executes workflows to remedy the particular issue.

Abstract: A troubleshooting technique provides faster and more efficient troubleshooting of issues in a distributed system, such as a distributed storage system provided by a virtualized computing environment. The distributed system includes a plurality of hosts arranged in a cluster. The troubleshooting technique uses cluster-wide correlation analysis to identify potential causes of a particular issue in the distributed system, and executes workflows to remedy the particular issue.

Abstract: The disclosure provides automated update notifications. Embodiments include receiving, by a cloud provider, a request to manage updates for a computing device communicating with the cloud provider via a network. Embodiments include registering an agent at the computing device with the cloud provider as a recipient for an automated update notification based on configuration details of the computing device and detection of an update item related to an aspect of the configuration details. Embodiments include identifying, by the agent, the configuration details of the computing device, the configuration details comprising details of a hardware configuration of the computing device and a software configuration of the computing device. Embodiments include monitoring one or more databases for the update item. Embodiments include transmitting the automated update notification to the agent based on detection of the update item in the one or more databases.

Abstract: Example methods and systems for request handling with automatic scheduling are described. In one example, a computer system may receive, from multiple client devices, respective multiple requests that are generated and sent according to a first set of control parameters. Based on the multiple requests, request characteristic(s) may be monitored to determine whether an automatic scheduling condition is satisfied. In response to determination that the automatic scheduling condition is satisfied, the computer system may assign a second set of control parameters to the respective client devices and instruct the client devices to generate and send respective multiple subsequent requests according to the second set of control parameters to cause a modification of the request characteristic(s).

Abstract: Example methods and systems for request handling with automatic scheduling are described. In one example, a computer system may receive, from multiple client devices, respective multiple requests that are generated and sent according to a first set of control parameters. Based on the multiple requests, request characteristic(s) may be monitored to determine whether an automatic scheduling condition is satisfied. In response to determination that the automatic scheduling condition is satisfied, the computer system may assign a second set of control parameters to the respective client devices and instruct the client devices to generate and send respective multiple subsequent requests according to the second set of control parameters to cause a modification of the request characteristic(s).

Abstract: An emergency shut-off valve assembly includes a valve having a closure assembly that includes a closure member coupled to an arm that rotates about a shaft. The valve assembly also includes an actuation assembly having a securement member coupled to the shaft; and an electromagnet adapted to generate a first magnetic force in a first state and a second magnetic force in a second state. In the first state, a contact surface of the securement member is in contact with and magnetically coupled to a contact surface of the electromagnet such that the closure member, the arm, and the shaft are maintained in the first open position against a rotational force provided by a biasing member. In the second state, the closure member, the arm, and the shaft are rotated into the second closed position by the rotational force provided by the biasing member.

Abstract: A fixed lever and pin assembly may include a lever body having a front end, a back end, and an arm connecting the front end and the back end. The front end of the lever body may be operatively coupled to a control element of a regulator. The arm may be adapted to operatively couple to an actuator of a regulator. A pin may be fixed to the front end of the lever body and may be disposed through the front end in a direction perpendicular to first and second parallel sides of the lever body. The fixed lever and pin assembly may be an integrated piece and the pin may prevent the lever body from moving independently from the pin.

Abstract: A lever assembly for a flow regulator includes a damper to reduce unwanted movement of the lever in an opening and closing direction. The damper includes one or more resilient spring members that squeeze the lever with an amount of force sufficient to reduce unwanted pivoting of the lever without preventing the lever from pivoting in response to control movements of an actuator adapted to actuate the lever.

Abstract: An internal valve includes a valve stem disposed in a valve body, a poppet valve coupled to the stem, and a bleed valve coupled to the stem. The valve stem is shiftable from a first position in which the poppet valve and the bleed valve are closed, to a second position in which the bleed valve is open, and a third position in which the bleed valve is closed and the poppet valve is open, and the poppet may shift closed in response to a pressure change. The valve body includes a shoulder that is arranged for sealing engagement with a container flange and is between an inlet and a flange of the valve body and spaced away from the inlet. The shoulder is arranged on the valve body to place the inlet a desired distance away from the inner wall of the fluid container.

Abstract: An internal valve including a valve body, a poppet valve coupled to the valve body, a bleed valve, a stem slidably disposed in the valve body and operatively coupled to the bleed valve. The stem is shiftable from a first position wherein the poppet valve and the bleed valve are both closed, to a second position wherein the bleed valve is open, and a third position wherein the bleed valve is closed, the poppet valve is open, and the poppet valve may shift toward the closed position and the bleed valve may open in response to a pressure change. A spring seat is coupled to the stem via a retaining feature such that the spring seat is movably disposed in the valve body, and a spring is operatively coupled to the stem via the spring seat and configured to bias the stem toward the first position.

Abstract: An internal valve includes a valve stem disposed in a valve body, a poppet valve coupled to the stem, and a bleed valve coupled to the stem. The valve stem is shiftable from a first position in which the poppet valve and the bleed valve are closed, to a second position in which the bleed valve is open, and a third position in which the bleed valve is closed and the poppet valve is open, and the poppet may close in response to a pressure change. The internal valve includes a strainer having an extended portion to be positioned in a clearance space between an upper portion of the valve body and an opening of a fluid container. The strainer is arranged for securement to a mounting area of the valve body by at least one fastener.

Abstract: An internal valve includes a valve body, a valve stem, a poppet valve, and a bleed valve. The bleed valve includes a body with a bore. A spring seat fits within the bore and is coupled to the valve stem, and includes a guide sized to receive the valve stem and a flow aperture. The flow aperture defines a connecting bleed path that fluidly connects a bleed flow path and a bleed outlet. The valve stem shifts from a first position where the poppet valve and the bleed valve are closed, to a second position where the bleed valve is open and the poppet valve is closed, and a third position where the poppet valve is open and the bleed valve is closed. A spring disposed in the bore bears against the spring seat and is arranged to close the poppet valve and open the bleed valve.