SpyGuy
Mechanical
- Apr 7, 2005
- 1
This is for a fuel facility at a small, privately owned and operated airport in northern California.
We have two ASTs containing avgas & jet fuel. The tanks supply a dual-product fuel dispenser approximately 50 feet away. The fuel is drawn from the tanks by suction at the dispenser; there are no pumps in the tanks (i.e., the piping is not pressurized, except by the fluid head from the liquid in the tanks). Currently, the dispenser-supply piping is 1-1/2" Schedule 40 steel pipe with threaded fittings. The piping comes off an anti-siphon valve at the top of the tank and extends horizontally to the side of the tank. Then it drops down vertically to ground level. There it transitions to a horizontal run along the surface of the ground to the dispenser. None of the piping is below grade.
The person who previously operated this fueling facility had installed a makeshift secondary containment system over the supply piping, using a combination of black ABS drain pipe and rubber boots to fabricate the outer containment jacket. The ABS secondary containment starts on the vertical pipe drop (at the level of the top of the tank), and continues along the length of the pipe to the dispenser, where it is sealed off at the containment sump. Obviously, this "secondary containment" does not meet any code requirements and it has not held up well: the ABS pipe is cracked and broken in a number of places.
I have contacted several suppliers & contractors to try to learn the options available for the proper design and installation of our system. Interestingly, one local petroleum contractor stated that for the small volume of piping we have, that no secondary containment is required. Yet I know that the gentleman who installed the makeshift containment would not have done so unless someone of authority told him that secondary containment was required. So I am puzzled by the apparent contradiction. I'd prefer not to contact any regulatory agencies until we get all our ducks in a row.
Questions:
1. For the volume of product in our piping (50 feet of 1-1/2" threaded steel pipe, all aboveground), is any secondary containment required?
2. If containment is required, is the purpose of containment to prevent total drain-out (siphoning) of the tank? Or must it be able to stop even the smallest of spills? The reason I ask is that, if we elevated the pipe so that it is above the level of the top of the tank, then even if the pipe were severed, the most that would spill would be the contents of the elevated pipe. As it stands now, the 5 feet of pipe that is above the level of the tank is not in any secondary containment. So can we elevate all of our pipe to eliminate the need for containment on the elevated portion of the pipe (only adding containment for the small vertical drop to the dispenser)?
3. Does using welded pipe (instead of threaded pipe) make any difference to the above questions? I realize that welded pipe is stronger and less prone to leakage than threaded pipe. But are there any other advantages in terms of regulations and compliance?
We have two ASTs containing avgas & jet fuel. The tanks supply a dual-product fuel dispenser approximately 50 feet away. The fuel is drawn from the tanks by suction at the dispenser; there are no pumps in the tanks (i.e., the piping is not pressurized, except by the fluid head from the liquid in the tanks). Currently, the dispenser-supply piping is 1-1/2" Schedule 40 steel pipe with threaded fittings. The piping comes off an anti-siphon valve at the top of the tank and extends horizontally to the side of the tank. Then it drops down vertically to ground level. There it transitions to a horizontal run along the surface of the ground to the dispenser. None of the piping is below grade.
The person who previously operated this fueling facility had installed a makeshift secondary containment system over the supply piping, using a combination of black ABS drain pipe and rubber boots to fabricate the outer containment jacket. The ABS secondary containment starts on the vertical pipe drop (at the level of the top of the tank), and continues along the length of the pipe to the dispenser, where it is sealed off at the containment sump. Obviously, this "secondary containment" does not meet any code requirements and it has not held up well: the ABS pipe is cracked and broken in a number of places.
I have contacted several suppliers & contractors to try to learn the options available for the proper design and installation of our system. Interestingly, one local petroleum contractor stated that for the small volume of piping we have, that no secondary containment is required. Yet I know that the gentleman who installed the makeshift containment would not have done so unless someone of authority told him that secondary containment was required. So I am puzzled by the apparent contradiction. I'd prefer not to contact any regulatory agencies until we get all our ducks in a row.
Questions:
1. For the volume of product in our piping (50 feet of 1-1/2" threaded steel pipe, all aboveground), is any secondary containment required?
2. If containment is required, is the purpose of containment to prevent total drain-out (siphoning) of the tank? Or must it be able to stop even the smallest of spills? The reason I ask is that, if we elevated the pipe so that it is above the level of the top of the tank, then even if the pipe were severed, the most that would spill would be the contents of the elevated pipe. As it stands now, the 5 feet of pipe that is above the level of the tank is not in any secondary containment. So can we elevate all of our pipe to eliminate the need for containment on the elevated portion of the pipe (only adding containment for the small vertical drop to the dispenser)?
3. Does using welded pipe (instead of threaded pipe) make any difference to the above questions? I realize that welded pipe is stronger and less prone to leakage than threaded pipe. But are there any other advantages in terms of regulations and compliance?
