Scully WL-102 2" Whistler Fill Signal

The Scully WL-102 2" Whistler Fill Signal is a vent pipe audible level indicator used to signal when a storage tank is approaching full capacity during liquid-filling operations. It produces a whistle sound as air passes through the calibrated passage, which stops when the liquid level reaches the vent height, indicating the tank is full and preventing overfill conditions in HVAC systems. The unit is created for exhaust tube utilization with a hand-crafted whistle stem that ensures a uniform airflow response and accurate level detection. Used in fuel storage systems for heating oil, diesel, and similar liquids to prevent spills and improve filling accuracy.