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 2020 Schier Products Company, 10/12/2020
Part #: 4075-001-01
Find these instructions online at: schierproducts.com/gb-500

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 C24H2 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 Traffic or
Greenspace Areas
InterceptorInterceptor
Vehicular Traffic Areas
Rebar
4" min. slab 8" min. slabRebar
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 traffic 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"
page 3 of 12
Schier | GB-500 Installation Guide
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.

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 diffuser
12. Inlet diffuser retaining nut
13. Inlet diffuser foot retaining nut
14. Inlet diffuser (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 diffuser retaining nut
22. Outlet diffuser
23. Outlet bulkhead connection
(optional) 4" FPT (x2)
24. Outlet bulkhead connection
(standard) 4" FPT
25. 7/16" nut driver bit
1 18
19
2
3
20
21
22
4
5
9
6
7
8
23
16
24
8
7
7
8
23
9
2
3
5
6
10
11
12
13
14
7
8
15
16
17
25
4
17
Schier | GB-500 Installation Guide
page 4 of 12

Fill Line
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"
page 5 of 12
Schier | GB-500 Installation Guide

3 Set Up Outlet Diffuser 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 diffusers.
3c Cap unused connections(all configurations)
Side Outlet:
Go to Step 3b.
Straight
Through:
Go to Step 3c.
3b Reposition outlet diffuser (side outlets only)
Remove safety star insert, leave tethered to unit. Unscrew diffuser retaining nut and remove outlet
diffuser. Rotate diffuser toward chosen outlet, insert and hand tighten retaining nut.
Schier | GB-500 Installation Guide
page 6 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/increased 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).
page 7 of 12
Schier | GB-500 Installation Guide
4 Install Inlet Diffuser Components
4a Install flow control
Unit with 6" Diffusers
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 diffuser 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" Diffusers
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

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
Schier | GB-500 Installation Guide
page 8 of 12

Above Grade Support Kit - AGS2
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.
page 9 of 12
Schier | GB-500 Installation Guide

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 10 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 Traffic Areas:
Minimum 8" thick concrete slab with rebar required. Thickness of concrete around covers to be
determined by specifying engineer. If traffic 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 Traffic or Greenspace Areas:
Minimum 4" thick concrete slab with rebar required.
10b Pour concrete slab to finished grade
Rebar
page 11 of 12
Schier | GB-500 Installation Guide
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

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 Efficiency
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"
Schier | GB-500 Installation Guide
page 12 of 12