What must indirect vaporizers be equipped with to prevent liquid from passing through?

Indirect vaporizers must be equipped with an automatic means to prevent liquid propane from passing through. This is critical because if liquid propane were to pass through the vaporizer, it could lead to operational failures, equipment damage, or hazardous situations. The automatic means typically refers to a system or mechanism designed to detect and prevent the flow of liquid, ensuring that only vapor is delivered for use.

The need for this safety feature is emphasized by the fact that vaporization relies on converting liquid propane into a gaseous state for proper functioning in various applications. Without such a system in place, there’s a risk of malfunction or unsafe conditions.

While other options, like an automatic shutdown valve or an emergency relief valve, are important in a propane system's overall safety and operational integrity, they serve different purposes. The automatic shutdown valve may stop flow during certain conditions, and the emergency relief valve is designed to release excess pressure. However, to specifically prevent liquid from passing through the vaporizer under normal operations, an automatic means is essential.