Which valve has a more reliable seal at higher pressures in a refrigeration system?

In refrigeration systems, the reliability of a valve's seal under higher pressures is crucial for maintaining system integrity and efficiency. Ball valves are generally preferred in these applications due to their design, which allows for a tighter seal compared to butterfly valves.

Ball valves feature a spherical closure element that rotates to open or close the flow path. This design enables them to achieve a very tight seal, even under high pressure, minimizing the risk of leaks. Additionally, ball valves are less susceptible to wear over time, which is particularly important in systems that operate under varying pressures.

On the other hand, butterfly valves utilize a disc that rotates within the flow path to control fluid movement. While they can handle pressures to some extent, they do not provide as effective a seal as a ball valve at higher pressure levels. Their design is more suitable for applications requiring quick shut-off and flow regulation but may not hold up as well under extreme pressure conditions.

Given these points, one can understand why ball valves are generally preferred for reliable sealing in high-pressure scenarios within refrigeration systems. Thus, the indication that neither the butterfly nor the ball valve is reliable at higher pressures is not accurate.