When tanks are buried more shallowly than normally, sometime piping designers or installers face issues with the piping. The reason is that at a filling station all piping should have a gradual slope to the low point, which is at the tank lid.
Gradually sloping pipe runs are needed to avoid air pockets in suctions systems and liquid traps in vapor recovery lines, both of which would impair proper operation of the filling station. But sloping pipes also to make it possible to drain the piping system whenever work needs to be done on the system.
Why shallow tanks?
Sometimes tanks are buried shallowly because of the cost of digging or due to specific ground conditions. Maybe you want to avoid blasting away rocks because of the surrounding buildings. When old tanks are reused, or new ones installed using the old foundation, the burial depth was designed for steel piping or in some cases the new tanks are bigger.
Here are a few simple solutions that will save on vertical build:
1. Compact double wall elbow for fill lines
This one can be used instead of a formed bend. The formed bend will give better flow characteristics, but it will require more space, even if you can trim it back some.
2. Compact double wall elbow for product lines
This is basically the same thing, but for product lines. This one will fit under dispensers and under vents stacks. Again, it is much more compact than a formed bend. Even if you trim the formed bend it can never become as compact as the elbow.
3. The small, long KP T
This fitting terminates the secondary containment created by the outer pipe in a double wall system - but it also provides the option to weld a plastic to steel transition fitting directly to it.
Instead of using 3 different components to transition from plastic double wall to single wall steel, you need only 2, which will save lots of space under dispensers!