Schier GB-500 User manual

Contents
Special Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Getting to Know the GB-500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11
Series Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
INSTALLATION GUIDE
GB-500 100 GPM Great Basin™Indoor/Outdoor Grease Interceptor
913-951-3300 | schierproducts.com
© Copyright 2023 Schier Products Company, 01/01/23
LIFETIME GUARANTEED GREASE INTERCEPTORS

SPECIAL PRECAUTIONS
Do not install this unit in any manner
except as described in these instructions.
Doing so may result in property damage, personal injury or death.
DO NOT AIR TEST UNIT OR RISER SYSTEM!
For Schier Grease Interceptor Installations - Failure to follow this guidance voids
your warranty
Install interceptor as close as possible to
fixtures being served
Provide at least 16" clearance
above unit for routine
maintenance.
Installation Instructions
Installation instructions and additional
components are included with the interceptor.
Read all instructions prior to installation. This
interceptor is intended to be installed by a
licensed plumber in conformance with all local
codes.
16" min.
ODOR ALERT!
Interceptor is not a
sewer gas trap.
All upstream fixtures
must be trapped
If water is entering the interceptor at excessive temperature (over 150º F), a
drain water tempering valve (DTV) and approved backflow prevention assembly
must be installed. Most state and local plumbing codes prohibit water above
150º F being discharged into the sanitary sewer. Water above 150º F will
weaken or deform PVC Schedule 40 pipe, poly drainage fixtures like
interceptors and erode the coating of cast iron (leading to eventual failure).
High Temperature Kitchen Water
ODOR ALERT!
Do not install air gap on outlet
side of interceptor.
Fully Support Base of Unit
Install unit on solid, level surface in
contact with the entire footprint of
unit base
Support Inlet and Outlet Piping
For above grade installations ensure
heavy inlet and outlet piping (such as cast iron or
long runs) is properly supported or suspended
during the entire installation process to prevent
connection failure or damage to bulkhead fittings.
DO NOT USE CAST IRON
COVERS IN ABOVE GRADE OR
INDOOR INSTALLATIONS
Use composite cover C24BC for above
grade installations
AGS2
Above Grade Installation Support
The wet weight of the interceptor combined with
high temperature kitchen water creates the
potential for tank deformation when installed above
grade. Model GB-500 installed above grade must
be installed with Above Grade Support Kit model
AGS2 to maintain structural integrity.
pipe supports
Schier | GB-500 Installation Guide
page 2 of 12

InterceptorInterceptor
Pedestrian Trac or
Greenspace Areas
InterceptorInterceptor
Vehicular Trac Areas
Rebar
4" min. slab 8" min. slab
Rebar
SPECIAL PRECAUTIONS
For Schier Grease Interceptor Installations - Failure to follow this guidance voids your
warranty
Max Water Level
Risers are not designed
to retain water
Installations with Risers
Corrugated Riser Pipe
Requirements
Riser adapter model CA2 must be
used when installing interceptors
using 24" diameter corrugated
pipe as a riser. This will
adequately embed the cover
adapter in the concrete slab,
preventing cover/cover adapture
failure under trac rated loads.
CA2
3 FCR2 Risers Max
94"
94"
Below Grade Installation Slab Requirements
A concrete slab to finished grade with rebar is required when installing
interceptor below grade.
6 - 94"6 - 94"
Hydrostatic/
Pressure Slabs
When installed under a
hydrostatic slab (slab
designed to withstand upward
lift, usually caused by
hydrostatic pressure)
interceptor must be enclosed
in a watertight concrete vault.
DO NOT
COMPACT BACKFILL
MECHANICALLY
Compact by
hand only
concrete slab subject to hydrostatic pressure
watertight
concrete
vault
High Water
Table Installations
Interceptors and risers are not
designed to withstand water table
height in excess of the top of the unit
when buried (see figure). If it is
possible for this to occur, install the
interceptor and risers in a water-tight
concrete vault or backfill with concrete
or flowable fill (wet concrete and
flowable backfill should be poured in
stages to avoid crushing the
interceptor). At risk areas include but
are not limited to tidal surge areas,
floodplains and areas that receive
storm water. Great Basin™models that
are direct buried in high water table
scenarios must be installed with an
anchor kit. Model GB-500 uses either
two model AK1 anchor kits or one AK2
anchor kit.
max water table height for
direct burial
(2) model AK1
anchor kits
InterceptorInterceptor
max water table height for
direct burial
(1) model AK2 anchor kit
with deadmen anchors
InterceptorInterceptor
Secure Cover Adapters
Cover adapters must be secured to
base units in above grade
installations with increased head
pressure conditions. Use cover
adapter tie-downs included with
Above Grade Support Kit model AGS2.
Schier | GB-500 Installation Guide
page 3 of 12

flow control
cartridge (red)
GETTING TO KNOW THE GB-500
1. Pickable cast iron cover (standard)
2. Cover gasket
3. Safety Star® access restrictor (x2)
4. Safety Star® tether (x2)
5. Cover adapter (x2)
6. Cover adapter gasket assembly(x2) with
upper and lower stainless steel band
clamps
7. Bulkhead connection retaining nut
8. Bulkhead connection gasket
9. 4" cleanout plug (x2)
10. Flow control cartridge (for >13' below
kitchen, 200 GPM only), see page 7 for
more information.
11. Inlet diuser
12. Inlet diuser retaining nut
13. Inlet diuser foot retaining nut
14. Inlet diuser (foot)
15. Inlet bulkhead connection (standard) 4"
FPT
16. 4" plain end fitting (x2)
17. 3" plain end fitting (x2) (optional)
18. Composite cover bolts
and washers (x8)
19. Bolted composite cover (optional)
20. Air relief/visual access
21. Outlet diuser retaining nut
22. Outlet diuser
23. Outlet bulkhead connection (optional) 4"
FPT (x2)
24. Outlet bulkhead connection (standard)
4" FPT
25. 7/16" nut driver bit
Schier | GB-500 Installation Guide
page 4 of 12
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7
8
23
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24
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Fill Line
Schier | GB-500 Installation Guide
page 5 of 12
1a 1b
1c
Have a Leak?
Call customer care at 913-951-3300
Hours 8am-5pm CST, M-F
1Test Tank for Water Tightness
Cap all connection points with 4" cleanout plugs using pipe thread
sealant or tape approved for use with plastics.
Remove covers. For base unit testing fill with water to just
above the highest connection.
Inspect unit, connections and gaskets for leaks. Check water
level at specific time intervals per local code.
Excavate hole at least 18" larger than interceptor on all sides and 12" deeper than tank bottom. Lay a level bed of well-packed,
crushed aggregate (approximately 3/4" size rock or sand, with no fines) in the base of hole.
12" or more
2 Excavate Burial Pit
18" 18"
12"

Schier | GB-500 Installation Guide
page 6 of 12
3 Set Up Outlet Diuser and Install Cleanout Plugs
3a Choose outlet location.
Screw in provided 4" cleanout plugs using pipe thread sealant or
tape approved for use with plastics. Do not cap the inlet or outlet
connections attached to the diusers.
3c Cap unused connections(all configurations)
Side Outlet:
Go to Step 3b.
Straight
Through:
Go to Step 3c.
3b Reposition outlet diuser (side outlets only)
Remove safety star insert, leave tethered to unit. Unscrew diuser retaining nut and remove outlet diuser. Rotate
diuser toward chosen outlet, insert and hand tighten retaining nut.

Schier | GB-500 Installation Guide
page 7 of 12
Flow control is not pre-installed on this unit.
• If dimension "A" is 13 feet or less no flow control is
needed, go to Step 5, Connect Piping.
• If dimension "A" is more than 13 feet, or a high flow/in-
creased head pressure condition exists, follow Steps
below.
Note to Plumbing Inspector
This interceptor includes certified internal flow control and does not
require a dedicated “Flow Control Vent” (air intake).
4 Install Inlet Diuser Components
4a Install flow control
Unit with 6" Diusers
Before
connecting piping
and burial, fasten
flow control plate
to inlet bulkhead
fitting using
supplied screws.
Holes in plate must
line up with
pre-drilled holes in bulkhead fitting and grooved
side of plate must face the unit.
Flow Control
Plate
Inlet
Bulkhead Fitting
Remove Safety Star® insert and remove flow control cartridge from the parts
bag. Slide flow control cartridge into top of inlet diuser and rotate clockwise
until cartridge drops onto the retainer pins. Continue rotating clockwise until pins
are fully seated.
retainer pin
receiver
slot
Unit with 4" Diusers
For easy flow control cartridge removal in
deep burial installations, 1-1/2" PVC SCH.
40 pipe may used as an extension
handle. Before risers have been installed,
cut pipe to length and attach to top of
cover using PVC primer/cement.
Extension handle length should be about
12" shorter than total riser height.
4b OPTIONAL: install extension handle
Finished installation
showing optional
extension handle

Schier | GB-500 Installation Guide
page 8 of 12
5a Install plain end fittings
5b Connect interceptor to drain lines
5 Connect Piping
Screw plain end fittings (included) into bulkhead fittings using pipe thread sealant or tape approved for
use with plastics. 6" connection types come pre-installed from the factory.
Place unit into final position and set level. Mechanically couple inlet and outlet drainage lines to unit. Do not
solvent weld. Ensure all upstream fixtures are trapped. Vent per local code. Installation of 2-way cleanout tees to
grade (by others) is recommended for buried installations.
Outlet
2-Way
cleanout tee
Inlet
BURIED INSTALLATION
Kitchen floor
Add this vent if unit is installed one
or more floors below the fixtures
being served
Vent per local code
FLOOR BELOW INSTALLATION
COUPLING DETAIL
Drain line
Flexible coupling
Plain end fitting
Bulkhead fitting
4" Plain End
4" FPT
4" FPT

Above Grade Support Kit - AGS2
Schier | GB-500 Installation Guide
page 9 of 12
7 Wet or Air Test Piping Per Local Code
Doing so may result in property damage, personal injury or death.
DO NOT AIR TEST UNIT OR RISER SYSTEM! Have a Leak? Call customer care
at 913-951-3300
Hours 8am-5pm CST, M-F
6 Install AGS2 Above Grade Kit (sold separately)
The wet weight of the interceptor combined
with high temperature kitchen water creates
the potential for tank deformation in above
grade installations. In these situations Above
Grade Support Kit model AGS2 is required to
be installed to maintain GB-500 structural
integrity.

Schier | GB-500 Installation Guide
page 10 of 12
8 Bring Covers Flush-to-Grade
The GB-500 is ready for burial depth of 49-1/2" from finished grade to bottom of tank (or 10-1/2" to centerline of inlet).
Deeper burials will require extending the cover adapters and possibly adding risers.
Measure dimension X to determine riser height needed.
8a
See instructions included with FCR2.
Riser Height Risers
Needed Required
0" - 4" None (use adapter)
>4" - 34" FCR2 (x2)
>34" - 64" FCR2 (x4)
>64" - 94" FCR2 (x6)
Loosen the cover adapter upper band clamp
using 7/16" nut driver bit. Adjust cover adapter
heights as needed. Maintain a minimum
2-1/2" insertion depth. Tighten upper band
clamp to 5 -8 ft. lbs. of torque using 7/16" nut
driver bit. If required, cover adapters may now
be tilted up to 10º in any direction using gasket
flexibility.
8c Make final cover adapter adjustments
8b Install risers if required
COVER ADAPTER ADJUSTMENT DETAIL
2-1
/
2" minimum
Cover
Safety Star
access restrictor
Cover adapter
Gasket
Upper band clamp
Lower band clamp
Interceptor accessway

Schier | GB-500 Installation Guide
page 11 of 12
TOP VIEW 18"
min
45º
18"
min
18"
min
18"
min
Concrete Slab
Rebar
9 Install Anti-Flotation Anchor Kit
10 Backfill and Finished Grade
Fill unit with water for stabilization and float-out prevention. Backfill evenly around tank using crushed aggregate (approximately 3/4" size
rock or sand with no fines)or flowable fill. Do not compact backfill around unit.
10a Backfill
Vehicular Trac Areas:
Minimum 8" thick concrete slab with rebar required. Thickness of concrete around covers to be determined by
specifying engineer. If trac loading is required the concrete slab dimensions shown are for guideline
purposes only. Concrete to be 28 day compressive strength to 4,000 PSI. Use No. 4 rebar (ø 1/2") grade 60
steel per ASTM A615: connected with tie wire. Rebar to be 2-1/2" from edge of concrete and spaced in a 12"
grid with 4" spacing around access openings.
Pedestrian Trac or Greenspace Areas:
Minimum 4" thick concrete slab with rebar required.
10b Pour concrete slab to finished grade
Rebar
DO NOT COMPACT BACKFILL
If the installation location is in a high
water table or at risk area (including but
not limited to tidal surge areas,
floodplains and areas that receive storm
water) the GB-500 must be installed
with either (2) Schier model AK1 anchor
kits or 1 model AK2 anchor kit (with
deadman anchors by others).
(1) AK2 INSTALLATION
(2) AK1 INSTALLATION
Deadmen anchors
(by others)
Model AK1
anchor kits

Schier | GB-500 Installation Guide
page 12 of 12
SERIES INSTALLATIONS
For lower flow rates and higher grease
storage requirements. Piping between
units and two-way cleanout tees by
others.
Below grade installations: All units
must be level in the excavation pit.
Note that downstream units must be
buried 2" deeper than the adjacent,
upstream fixture. Two-way cleanout
tees extended to finished grade
should be installed before the first unit
inlet, after the last unit outlet and in
between units (if there is a long run of
pipe between units) for line cleaning
purposes.
NOTE: When the flow control
cartridge is required, it should only be
installed on the first unit in the series.
Top View of 4 GB-500 Units Piped in Series
Side View of 3 GB-500 Units Piped in Series
Rated Grease Capacities
for Units Piped in Series
No. of Removal Eciency
Units 100 GPM
in Series 95.3%
2 6,096 lbs.
3 9,144 lbs.
4 12,192 lbs.
Two-way cleanout tee extended to grade
(provided by others)
2"