In a liquid fuel system, what is the critical measurement for vent caps?

In a liquid fuel system, the critical measurement for vent caps is the cross-sectional area of the vent pipe. This measurement is essential because it directly affects the venting capacity of the system. A sufficient cross-sectional area is necessary to allow the proper flow of vapor and prevent pressure build-up in the system. If the area is too small, it can lead to insufficient venting, which may cause operational issues or safety hazards, such as overpressure conditions.

The design of the vent cap and pipe must ensure that vapor is able to escape as the liquid fuel expands due to temperature changes or during liquid movement. Adequate venting helps maintain atmospheric pressure balance, preventing failure of containment and ensuring safe system operation.

While the height, length, and weight of the vent cap can all have roles in the overall design and function of the venting system, the cross-sectional area is the primary factor that ensures optimum venting performance and safety in a liquid fuel system.