This document describes the steps to manually refuel a Chart LNG vehicle tank.
This document provides detailed instructions for manually defueling Chart LNG vehicle tanks, designed for trained technicians. It covers safety precautions, equipment needed, and step-by-step procedures for removing LNG, including handling dual-tank systems and transferring fuel between tanks. Safety is emphasized throughout, including ventilation, grounding, and proper PPE use.
The guide also includes specific steps for tanks with low pressure (0–2 bar), requiring nitrogen gas to increase pressure before defueling. It explains how to transfer fuel between tanks in integrated and non-integrated systems, including handling excess flow valves and maintaining pressure differentials for efficient transfer.
Close valves on both tanks, defuel one tank, then slowly open the liquid valve on the other tank to transfer fuel. If the excess flow valve sets, close the valve until it resets, then reopen.
Introduce nitrogen gas into the tank to increase pressure to 7 bar before proceeding with defueling.