Velvac 600051-6 Locking Fuel Tank Cap

The Velvac 600051-6 Locking Fuel Tank Cap is a heavy-duty aluminum cap for diesel-powered commercial vehicles and industrial equipment, pairing a locking mechanism with a fused vent design to prevent unauthorized fuel access while preserving proper tank ventilation. It uses 2-1/8 in male threads (12 TPI), with a cap diameter across threads of 2-1/4 in and a filler neck across threads of 2-1/16 in, and its vented pressure-relief is integrated into the fused vent system; keys are supplied for operation. Designed for OEM replacement or maintenance, it is commonly used on heavy-duty trucks, buses, construction equipment, agricultural machinery, and other diesel-powered vehicles with compatible 2-1/8 in threaded filler necks. Manufacturer Velvac Inc.; Part Number 600051-6; common replacements include Velvac 600037-6, 601056-6, and 600183-6.