What should the nominal size of an automatic relief valve be for pumps with a capacity of 3000 gpm to 5000 gpm?

The nominal size of an automatic relief valve for pumps with a capacity between 3000 gpm and 5000 gpm is typically 1 inch. This size is selected based on ensuring that the valve can handle the required flow rate without causing excessive pressure build-up or creating hydraulic shock in the system. A 1-inch valve provides a balance between the need for adequate flow and the ability to manage the pressure efficiently, which is essential for maintaining system integrity and performance.

When dealing with larger pump capacities, it is crucial that the relief valve is appropriately sized to prevent damage to the system components. Smaller sizes, such as 1/2 inch or 3/4 inch, would not be able to accommodate the flow demands of a pump in that range, potentially creating a backpressure situation or failure to relieve pressure effectively. Valves larger than 1 inch, like 1 1/4 inch, may lead to increased costs and may not be necessary unless specific system conditions require it. Hence, 1 inch is the correct and most efficient choice for this application.