Truck Load Out
Prevent Tanker Truck Fires
Every year, truck fires and even tank fires occur because of improper static bonding during load out. The loading and unloading process of tank trucks transporting large quantities of flammable semi-conductive fluids generates static electricity. If this static charge is not grounded appropriately, it can result in a static spark in a vulnerable location.
Often truck operators carry their own static bonding clamp, however, the hardware can be damaged or not function properly. If the grounding stations are not available at the truck load-out stations, truck operators do not know where to make the grounding attachment, occasionally connecting to non-grounded or isolated grounds. The static protection standard NFPA 77 requires there to be a visible truck grounding station available wherever a truck load-out is located. To further eliminate the risk of static discharge, the NFPA and API also recommend that vacuum truck operators transferring flammable and combustible product in hazardous locations must fully ground the truck prior to any other task in the transfer operation by connecting the truck to a proven ground source.
Petro Guardian manufactures and installs the appropriate truck load-out assembly to bond and ground the truck before starting the transfer operation. In the installation process, we create a grounding station at the load-out by installing a ground rod and bonding it to the fill pipe. We then attach a truck bonding assembly to this grounding station. The clamp on this assembly is to be attached to the truck body. The clamp is secured to a 20-foot copper lead and a shorter length of steel aircraft cable. If an operator forgets to remove the clamp after transfer activity, the aircraft cable will snap tight and release the clamp from the vehicle. Finally, we mark the grounding station with clear signage. Our truck load out grounding and bonding assembly ensures any static on the truck is grounded before the transfer hose is attached and the static electricity generated during the transfer process is rapidly grounded.
There are three key functions that must be in place before the loading/unloading operation can begin:
- Verify that the grounding clamp is connected to the ground
- Verify that the ground is bonded to the loadout pipe
- Connect grounding clamp to the tank truck body