Industrial butterfly valves.
Type: They appear to be lug-style valves, designed to fit between two pipe flanges and suitable for dead-end service.
Size: Based on the context, these are likely 4-inch valves, commonly used in water supply, HVAC, and industrial piping systems.
Operation: They feature manual hand levers for quick quarter-turn operation to open or close flow.
Materials: Typically constructed with a ductile iron body and stainless steel disc for durability.