Fuel tank air escape outlets are fitted with flash screens of what mesh size?

Flash screens on fuel tank air escape outlets are designed to prevent flashback of flames while allowing air to escape. The mesh size of 40 is specifically selected because it is effective in preventing ignition sources, such as sparks, from entering the tank while still permitting necessary ventilation. This balance is critical for maintaining safety in fuel systems, as the right mesh size helps mitigate risks associated with flammable vapors. A finer mesh, such as 50, could restrict airflow too much, potentially leading to pressure buildup, while a coarser mesh like 20 or 30 would not provide adequate protection against potential ignition sources. Therefore, using a 40 mesh size flash screen is a standard practice in ensuring safety and efficiency in fuel tank ventilation systems.