The upper spring plate, designated as K 27501, is part of the inlet valve assembly in the ZV40/48 diesel engine. Positioned at the top of the valve spring, it evenly distributes the spring force and helps maintain correct alignment of the inlet valve during operation. This plate must withstand high cyclical loads and elevated temperatures, making material strength and structural integrity crucial. A well-functioning upper spring plate ensures reliable valve movement, which is vital for efficient air intake and overall engine breathing performance.