If the check valve springs are interchangeable on a double check assembly, what impact does this have?

When check valve springs in a double check assembly are interchangeable, it means that the spring tension and characteristics are standardized across those valves. This interchangeability does not inherently impact the downstream pressure. The function of the check valve is to prevent backflow by closing when there is a reverse flow. If the springs are interchangeable, they will maintain the same operational characteristics across the assembly, ensuring that the valves operate consistently regardless of which specific spring is used.

Since the design and operation of the double check assembly remain unchanged, the hydraulic performance should also remain stable, meaning the downstream pressure is not affected by simply changing the springs. This allows for ease of maintenance without compromising the system's pressure dynamics, ensuring that there is no unintended consequence affecting the flow or pressure within the system.