Skimmer Layout And Line Sizing; Installation - Pentair STA-RITE U-3 Skimmer Installation Manual

4
Skimmer Layout and Suction Line Sizing
NOTE: In any installation, there should be at least two main
drains at least three feet apart in addition to any skimmers
installed. A pool may use more than two, but should never have
less than two main drains.
NOTICE: Installation must comply with all applicable codes,
including NSF Standard 50 (if required). Equalizer lines may be
required on public pool or commercial pool installations.
1. Use one skimmer per 500 square feet of pool
surface area. Suction line sizes are based on a
water velocity of less than seven feet per second.
Since building codes vary, check your local building
code before installing pool and skimmers.
2. Suction line sizes for each section of piping must
allow for the total number of skimmers feeding that
section of the line. Suction line sizing in Chart I
allows for this.
3. See Figures 5 and 6, Pages 2 and 3, for piping
layout. See Table I, Page 3, for suction pipe sizing.
4. For good hydraulic balance, divide skimmers as
equally as possible between the main branches of
the piping layout.
5. For long pipe runs (in which friction can reduce flow
and pressure), refer to your friction/flow chart for
proper pipe sizes.
6. When planning location of skimmers on one and
two skimmer outdoor pools, locate skimmers so that
the prevailing wind blows into the skimmers.

INSTALLATION

All installation instructions in this manual are general
guidelines. Actual skimmer installations may vary by local
practices and codes.
NOTICE: Skimmer should be surrounded by at least 4 inches of
structural concrete in a monolithic pour, using a cold joint as shown
in installation drawings. Concrete: See Figure 7 for dimensions.
Line Connections and Testing: Connect pump inlet line to rear
port in bottom manifold (Figure 7). Skimmer is ABS plastic; manifold
connections are 1½ inch or 2 inch threaded or 1½ inch slip. For
threaded connections, do not use pipe dope; to seal joint use RTV
Silastic #732* (preferred), Teflon® tape, or Plasto-Joint Stik®. For
slip connections, apply PVC primer to PVC pipe only. Then apply
ABS to PVC solvent cement to both pipe and slip connections.
Consult dealer for correct solvent cement for pipe used. Assemble
joint per cement manufacturer's instructions. Allow at least three (3)
hours before pressure testing.
Plastic cements and primers can be flammable, poisonous, or both.
Closely follow cement manufacturer's instructions when using
plastic cement. For residential installations where equalizers are
not required and where the main drain lines do not connect to the
skimmer equalizer port, low water levels in the pool, spa, or hot tub
or clogged skimmer baskets may damage the pump due to loss of
prime (if skimmer sucks air) or cavitation (if skimmer clogs). Air
pulled in by skimmer(s) can be trapped in filter tanks, which may be
a safety hazard. If skimmer regularly vortexes or sucks air, raise
water level or contact your pool service representative for advice.
U-3 Skimmer Installation Guide
CONCRETE
18"
Top View
1" Vertical
adjustment of frame
to accommodate for
misaligned pump
suction
To
pump
suction
19"
Min.
26"
Alternate Line
from Main Drain
Section View
Install an equalizer
fitting that
conforms to
ANSI/ASME
A112.19.8.
Note: To prevent
entrapment,
cover must fit
tightly onto
fitting.
Figure 7: U-3 Skimmer Installation Illustration
10"
27"
27"
11¼" Ref.
7½"
1"
W.L.
2"
2"
Equalizer
Front View
18"
Ref.
2"
Min.
W.L.