What is the minimum mesh size required for vent caps in a liquid fuel system?

The minimum mesh size required for vent caps in a liquid fuel system is designated as No. 4. This size is selected to ensure that adequate ventilation is provided while preventing the ingress of larger contaminants, such as insects or debris, which could compromise the system's integrity or functionality.

A mesh size of No. 4 signifies that the openings are small enough to filter out unwanted particles while still allowing for sufficient airflow, which is crucial for maintaining proper pressure and vapor management in liquid fuel systems. Proper venting helps prevent the buildup of pressure and supports the safe operation of the system.

The other mesh sizes, such as No. 2, No. 6, and No. 8 either provide insufficient filtering capacity or may be too restrictive for effective ventilation in a liquid fuel application. Therefore, selecting mesh size No. 4 aligns with industry standards and safety practices, ensuring operational efficiency and safety.