Dispenser Safety Equipment: Emergency Shutoff Valve

Written by: Brian Pottebaum, Director of Training Services

Retail fueling facilities and convenience stores require additional safety devices and procedures for petroleum related accidents that can occur. Customers flock to these facilities for fuel, snacks and refreshments, lottery tickets, and lunch breaks, just to list a few. At certain times of the day, these facilities get very hectic, and it only gets more frantic if there is bad weather like rain or snow.

Constant traffic over and around the fuel storage system, including the dispensers, can be the recipe for disaster if proper precautions are not taken. Trained and experienced facility operators are an important factor at these fueling facilities. Additionally, emergency plans must be developed to include preventative measures and responses to various emergency situations. All employees need to be routinely trained on these emergency procedures.

The petroleum industry has recognized the potential for disaster and is continually researching and developing new emergency devices that can be installed to help prevent or at least minimize damage during accidents.

What is an emergency shutoff valve?

One of these “emergency” devices is an emergency shutoff valve (also sometimes called a shear valve, impact/crash valve, or fire valve). It is installed at the base of a fuel dispensing cabinet and is designed to close and stop the flow of fuel when there is a collision or fire at the dispenser.

The mechanical valve can function in two different ways. Because the bottom half of the valve is rigidly anchored to the below grade structure, the valve will break along the engineered shear plane and separate the top half of the valve from the bottom half when the dispenser is struck. This causes the hold-open linkage (fusible link) to separate and the spring-loaded main poppet slams closed inside the bottom half, not allowing any product through the valve until it is repaired. Some emergency valves are also equipped with a secondary poppet in the top half that also closes when the valve is sheared, keeping product from leaking out of the dispenser cabinet.

The emergency valve is also equipped with a low-melting point “fusible link” that can also close the poppet valve if the dispenser is exposed to fire or excessive heat. Again, the main poppet closes and stops the flow of product to the dispenser. This can function even when the emergency shutoff valve is not separated (or sheared) by impact.