Disable ads (and more) with a membership for a one time $4.99 payment
How are most hydraulic systems protected against overpressure when control and relief units fail?
By activating an emergency bypass
With a shear section on the main hydraulic pump drive shaft
By automatically shutting down the system
Through external pressure relief valves
The correct answer is: With a shear section on the main hydraulic pump drive shaft
Most hydraulic systems are protected against overpressure when control and relief units fail by using a shear section on the main hydraulic pump drive shaft. This design feature allows for the drive shaft to break or shear off in case of an overpressure event, thereby preventing damage to the rest of the system. The other options, while they may play a role in overall system safety, do not specifically address protecting against overpressure in the event of control and relief unit failure. Option A refers to activating an emergency bypass, but it does not specify how the bypass works to protect against overpressure. Option C mentions automatically shutting down the system, but this does not necessarily address the issue of overpressure. Option D suggests using external pressure relief valves, which may be effective in certain situations, but may not always be present or activated in the event of control and relief unit failure. Thus, these options are incorrect or not as suitable as the use of a shear section on the main pump drive shaft for overpressure protection.