The shear valve is a very important safety device that is required to be installed where pressurized piping comes into the dispenser - as per 40 CFR § 280.20(f)(1). The purpose of the shear valve is to prevent petroleum products from entering into the dispenser cabinet in the event of a fire or impact to the dispenser.
If the shear valve is not installed properly, it will not function properly!
Take a look at the photo below (left). This is an example of an improperly installed shear valve. First of all, it looks like someone tried to install the valve using a face plate that was not necessarily to manufacturers specifications. Notice the large gap between the make-do face plate and the stabilizer bar. The shear valve should always be installed flush with the stabilizer bar. Additionally, they inappropriately tried to use a U Bolt to hold the face plate and due to way the bots were tightened, it is straining/bending the U Bolt plate. Chances are, this shear valve will not function properly in the event of an impact.
Take a look at the photo below (right). Did someone drop the nail clipper into the under dispenser containment? NO! Someone retrofitted a nail clipper to the shear valve to hold the release open. Needless to say, this does not meet manufacturer's specifications or your inspector's standards for that matter.
Neither of these shear valves will function properly if a vehicle strikes the dispenser or a fire occurs. While there are many very good technicians out there that know how to properly install shear valves, know what to look for in the event that you should hire one that does not. And please note . . .
Shear valves must be inspected for proper operation annually.
Are your Shear Valves installed properly?
And if you think the chances of a vehicle striking a dispenser are low, click the button below to see videos on YouTube. And these are only the ones that got posted.