The Sulzer ZV 40/48 engine incorporates advanced components like the underlay for the double non-return valve (K 46531), identified by code number K 46485. This underlay plays a vital role in ensuring the proper seating and operation of the double non-return valve, which is crucial for preventing backflow and maintaining optimal pressure within the engine system. By providing a secure and durable base, the underlay contributes to the reliability and efficiency of the engine, supporting its performance in demanding marine and industrial applications.