How does a slow opening valve differ from a quick opening valve?

A slow opening valve is designed to open gradually, which allows for a controlled increase in flow and pressure, minimizing the risk of water hammer or sudden pressure spikes in the system. This gradual operation is typically achieved through a design that requires more turns of the handle or actuator to fully open the valve, allowing for finer control over the flow rate.

In contrast, a quick opening valve is designed to open rapidly, requiring fewer turns or movements to achieve full opening. This type of valve is used in applications where rapid flow establishment is critical and is often employed in systems where quick response times are necessary.

The other options do not accurately describe the functional differences between slow opening and quick opening valves. For instance, a valve that opens without turning is not characteristic of either type, as both types require a mechanism to operate. Similarly, pressure ratings are not inherently tied to the speed of valve opening, and closing by lifting a handle describes a manual operation that could apply to either type of valve, depending on its design.