The casing K 43552 is an essential structural and pressure-containing component of the automatic starting-air stop valve used in the starting-air system of the Adriadiesel/Jugoturbina/Zgoda/Sulzer ZV40/48 engine. Its primary function is to provide a robust and precisely machined enclosure for the internal valve components, ensuring their correct positioning, alignment, and protection while maintaining the pressure integrity required for reliable starting-air control. The casing accommodates the associated valve seat, piston, and other operating components, providing the internal passages and supporting surfaces necessary for controlled admission and interruption of compressed air during engine starting. Accurate machining of internal bores, seating surfaces, threaded connections, and sealing interfaces is particularly important because dimensional inaccuracies, deformation, or surface damage can lead to air leakage, restricted component movement, or improper valve operation. During service, the K 43552 casing is subjected to repeated compressed-air pressure cycles, mechanical stresses, vibration, temperature variations, and extended periods of standby readiness, requiring high mechanical strength, dimensional stability, and resistance to corrosion and fatigue. During maintenance or overhaul, the casing should be carefully inspected for cracks, corrosion, worn guiding surfaces, damaged threads, deposits, deformation, and deterioration of sealing areas, with particular attention to the condition of the internal passages and mounting interfaces. By providing a secure and accurately dimensioned housing for the automatic starting-air stop valve, the K 43552 casing contributes to dependable valve operation, controlled starting-air distribution, reduced compressed-air losses, and reliable long-term starting performance of the ZV40/48 engine.