Which fixed displacement pump is least likely to suffer catastrophic failure and why?

The gear pump is least likely to suffer catastrophic failure because of its structural design and operational characteristics. Gear pumps function through the continuous engagement of gears, which creates a consistent flow of fluid. Over time, the wear of components in gear pumps tends to be gradual, allowing for maintenance and corrective measures to be taken before complete failure occurs. This characteristic reduces the likelihood of abrupt and catastrophic changes in performance since operators can monitor the condition of the pump and replace parts as necessary.

In contrast, other types of pumps may experience failure more suddenly due to their specific operational mechanisms. For instance, rotary vane pumps and piston pumps can suffer from issues like valve or seal failures, which may lead to significant operational disruptions. Meanwhile, screw pumps operate on a different principle and can be affected by external factors or design issues that may not provide the same predictability in wear and tear.

Thus, the gradual wear pattern of gear pumps makes them more resilient to catastrophic failures, as they can be serviced based on performance indicators, helping ensure their reliable operation over time.