For proper seating when closing a valve on a tank, which position should the valve be in?

The appropriate procedure for properly seating a valve on a tank is to ensure that it is closed against the stop and that the locking pin is inserted. This method guarantees that the valve is secured in place, which is crucial for preventing leaks and ensuring the safety of the cargo.

Closing the valve against its stop ensures that it is fully sealed, thereby preventing any potential leaks or pressure loss. By inserting the locking pin afterward, this provides additional security that the valve will remain in the closed position, even under varying operational conditions or pressure changes in the tank.

Using a valve wrench to tighten the valve could potentially over-tighten it, risking damage to the valve or its components. Similarly, leaving the valve in an intermediate position (like half open) could compromise the integrity of the tank by allowing unwanted flow. Therefore, the method of closing the valve against the stop and securing it with a locking pin is the most reliable and recommended approach for ensuring proper valve operation and tank safety.