What valve consists of two spring-loaded flaps seated into a housing?

• A. Non slam
• B. Check valve
• C. Butterfly valve
• D. Gate valve

Answer: (A)

The valve that consists of two spring-loaded flaps seated into a housing is indeed known as a non-slam check valve. This type of valve is designed to prevent backflow in a piping system while minimizing the slamming action of the flaps as the flow direction changes or stops. The springs provide a mechanism that allows the flaps to close softly, thereby reducing hydraulic shock and making the system more stable.

In contrast to check valves in general, which can allow for slamming if flow reverses too quickly, non-slam check valves use their design and internal mechanisms specifically to avoid that issue. Check valves can take various forms, but the emphasis on the spring-loaded flaps specifically recognizes the unique design of the non-slam version.

Other options like butterfly valves and gate valves serve different purposes and have distinct mechanisms. Butterfly valves utilize a rotating disc to regulate flow and are not spring-loaded, while gate valves use a linear motion to open or close the flow path and also do not have flaps. Thus, recognizing the specific construction and function of these valves helps clarify why the non-slam check valve is the correct choice in this context.