FFS-1072 Forecourt Guide 2025 2 - Flipbook - Page 26
APT® PIPE: B A C K F I L L I N G
Clean, compacted sand, pea gravel or 1⁄8 to ¾" (3.2 to 19 mm) or smaller crushed
rock (without sharp edges) should be used as backfill material. There must be a
minimum of 4" (10.16 cm) for APT® brand XP pipe and 6" (15 cm) for UPP® brand
pipe of approved backfill material under, and between, piping runs. Backfill material
must not be contaminated with any petroleum.
6" MIN CONCRETE OR 12" MIN
ASPHALT/OTHER COVER
APPROVED BACKFILL
12" MINIMUM
CONCRETE
BURIAL DEPTH
6" MINIMUM
BACKFILL
4" MINIMUM THICKNESS
OF APPROVED BACKFILL
BELOW PIPING RUN
6" MINIMUM DISTANCE BETWEEN
OUTSIDE OF PIPING RUN AND THE
TRENCH WALL (BOTH SIDES)
4" MINIMUM DISTANCE
BETWEEN PIPING RUNS
Note: If XP pipe is installed within ducting, adjacent ducting runs must be separated by a minimum
of 2" (51 mm) ensuring that the XP pipe maintains the 4" (102 mm) minimum separation distance.
UPP® PIPE: B A C K F I L L I N G
Recommended bedding/backfill materials for pipe burial:
• Well-rounded pea-gravel, 1⁄8"- 3⁄4" (3-20 mm)
• Clean, washed sand
• Crushed rock, 1⁄8"- 5⁄8" (3-16 mm)
SEPARATE PIPES BY Ø OF LARGEST PIPE
(”D1” SHOWN BELOW) IN RUN
12" (300 mm) MINIMUM
6" (150 mm) MINIMUM
d1
6" (150 mm) MINIMUM
150
d1
150
