FFS-0772 Forecourt Guide No 6 InteractiveSpreads - Flipbook - Page 15
APT® PIPE: B A C K F I L L I N G
APT® XP PIPE: C U T B A C K
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.
Once the pipe run is pulled and each section is cut to length, square off the end of the
pipe, de-burr it, and then proceed with the cut-back. If you are using SC (Secondary
Contained) piping, cut back the scuff guard layer even with or outside of the sump wall
and cut back the SC layer 4½" (11.5 cm).
6" MIN CONCRETE OR 12" MIN
ASPHALT/OTHER COVER
APPROVED BACKFILL
4.5" (11.5 cm)
12" MINIMUM
CONCRETE
BURIAL DEPTH
6" MINIMUM
BACKFILL
4" MINIMUM THICKNESS
OF APPROVED BACKFILL
BELOW PIPING RUN
Primary Jacket
(Free of clear mylar layer)
* Even with, or outside
of, the sump wall
Secondary Containment Jacket
6" MINIMUM DISTANCE BETWEEN
OUTSIDE OF PIPING RUN AND THE
TRENCH WALL (BOTH SIDES)
4" MINIMUM DISTANCE
BETWEEN PIPING RUNS
Scuff Guard
(Including metalized mylar layer)
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
NOTES:
Recommended bedding/backfill materials for pipe burial:
• Well-rounded pea-shingle, 3-20 mm
• Clean, washed sand
• Crushed rock, 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
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