What indicates a high-pressure type on an air valve core stem?

An embossed letter 'H' on an air valve core stem specifically signifies that it is a high-pressure type. This labeling is a standardized method used to ensure that technicians and operators can easily identify the type of valve core they are dealing with. High-pressure systems often require different handling and maintenance protocols compared to low-pressure systems, and the embossed letter serves as a quick reference to prevent mistakes that could lead to equipment failure or safety hazards.

While other options may refer to different characteristics of air valve cores, such as pressure handling capabilities or sealing mechanisms, only the letter 'H' unequivocally denotes a high-pressure type. This clear and specific designation is vital for maintaining operational integrity within systems where pressures can significantly impact performance and safety.