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Valve and Actuator Technology for the Offshore Industry
Published in Karan Sotoodeh, Coating Application for Piping, Valves and Actuators in Offshore Oil and Gas Industry, 2023
Answer: Electrical actuators typically cannot provide a fail-safe closed mode of operation. Since the actuated 38″ ball valve is fail-safe closed, then the remaining options for actuation are either pneumatic or hydraulic. A 38″ ball valve in pressure class 2,500 is a large valve in a high-pressure class, so it requires a large amount of force for operation; pneumatic actuators cannot generate the force required to operate such a large valve in such a high-pressure class. Thus, the correct actuator is hydraulic. A ball valve is a quarter-turn valve with rotary motion. The other type of actuator that provides a fail-as-is function is an electrical actuator. Electrical actuators provide both linear and rotary motion, so option B is the correct answer.
Blueprint Reading
Published in Frank R. Spellman, The Science of Wind Power, 2022
A Ball valve, as the name implies, is a stop valve that uses a ball to stop or start a flow of fluid. The ball performs the same function as the disk in other valves. As the valve handle is turned to open the valve, the ball rotates to a point where part or all of the hole through the ball is in line with the valve body inlet and outlet, allowing fluid to flow through the valve. When the ball is rotated so the hole is perpendicular to the flow openings of the valve body, the flow of fluid stops.
Water Distribution
Published in Samuel C. Sugarman, HVAC Fundamentals, 2020
A ball valve has a low pressure drop with good flow characteristics and is often used for water balancing. A butterfly valve also has a low pressure drop and is sometimes used as a water balancing valve. However, a butterfly valve does not have the good throttling characteristics of a ball or plug valve.
Research on the influence of the proportional relay valve on the economy and safety of the electric bus through the braking energy recovery system
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Ning Li, Chengkun He, Junzhi Zhang, Yingshuai Liu, Cheng Lin, Chao Li
In the formula:,is ball valve and valve seat quality (kg),is gravitational acceleration (m/s2),is ball valve displacement (m),is air pressure at backup intake port (Pa), is control chamber air pressure (Pa),is effective pressure area acted on the ball valve (m2),,is the spring stiffness of the support of the ball valve and ball seat (N/m),,is spring preload of the support of the ball valve and ball seat (m),,is equivalent viscous damping coefficient of ball valve and valve seat (N/(m/s)),is the initial clearance between the ball valve and the valve seat (m).
Development and control of an articulated mobile robot T2 snake-4.2 for plant disaster prevention – development of M2 arm and C-hand
Published in Advanced Robotics, 2022
Ching Wen Chin, Mizuki Nakajima, Koki Furuike, Kazuyuki Kon, Motoyasu Tanaka
According to Ref. [25], Omni-Gripper [27] that fitted on the T Snake-4 can only rotate valves with a small handle such as 15 A ball valve, 50 A ball valve and 80 A rubber seated gate valve but it is unable to rotate valve with a large handle such as 80 A ball valve (Figure 4). To rotate the valves with a large handle, we need to increase the size of the Omni-Gripper. However, the weight of the gripper may be increased accordingly and the mobility of the robot may degrade significantly. The Omni-Gripper could also be replaced with a lighter and simpler end effector such as the parallel gripper proposed in Ref. [6, 29]. Even with a lighter gripper, the robot is unable to rotate the 80 A ball valve because the arm may be twisted by the reaction force from rotating the valve due to the low rigidity of the folding arm.
Adaptive metamodel-based analytical target cascading for natural gas hydrates coring tool design optimization
Published in Engineering Optimization, 2021
Jun Zheng, Chunhua Lu, Zilong Li, Guosheng Jiang, Huibin Zhao
The proposed A-ATC approach is applied to the conceptual design of an NGH coring tool, aiming to improve on the performance of its predecessor under similar operating conditions. In this section, the A-ATC is used to deal with the design optimization problem of the NGH coring tool. Thus, the design optimization problem for the NGH coring tool is decomposed into pressure and strength subsystems of the cube tube, the hydraulic system of the starting mechanism and the mechanics subsystem of the ball valve, as illustrated in Figure 4. The system design goal aims to reduce the weight of the whole drill string as much as possible. For the core tube system, strength within a safe range is a requirement when reducing the weight. For the starting mechanism system, an appropriate hydraulic condition should be satisfied in order to release the starter ball and close the ball valve to maintain pressure. Once the ball valve is closed, a huge pressure exists on the ball valve; thus, a stress check and test are needed for the ball valve.