Should a piston pump discharge be open or not during the start of the pump?

A question of whether the piston pump discharge should be open or closed at start-up is important because it bears on the efficiency and safety of the pump’s operation. The appropriate setup for starting a piston pump depends on the specific type as well as its application. Yet there are some general ideas that can be used to guide such process.

Technical Considerations:

1. Hydraulic Pressure: A hydraulic pressure begins to build when a piston pump is started. With a closed discharge, this pressure can rise rapidly thus potentially damaging either the system or the pump itself.
2. Mechanical Stress: Doing so may expose some very high mechanical stress on the parts of the pump if one starts with a closed discharge due to resistance against fluid movement by the apparatus.
3. Priming: Some piston pumps require priming before they operate efficiently. In case it is necessary, having an open discharge line aids in priming through allowing air to escape and fluid to move through system.

Practical Considerations:

1. Safety: It is generally recommended that the pump must be started with an open discharge for safety reasons. This helps in avoiding excessive pressure buildup which could otherwise lead to dangerous situations like pipe bursts or damage of pumps.
2. Efficiency: Starting with an open discharge helps in quickly achieving operating efficiency of the pump because it allows smoother ramp up in pressure and flow reducing strain on a pump.
3. System Requirements: The design parameters for systems where these pumps are integrated must be taken into account. Based on what is being pumped, how much pressure is needed and other issues, different systems might have varied guidelines about how pumps should begin running.
4. Manufacturer’s Guidelines: Always refer to manufacturer’s guidelines specific for your particular piston pump model you are using .Starting procedures may vary depending upon different models and types .

Conclusion:

In general, it would be best if one starts a piston pump with its discharge valve opened. This approach tends to be safer thereby reducing mechanical stress upon pumping increasing its life span possibly bettering the efficiency. However, the type of piston pump, its application and manufacturer’s recommendations have to be thought about. There are instances when starting with a closed discharge may seem reasonable; however, this has to be done with full understanding of its implications and likely hazards.