Schier GB2 User manual

Contents
Special Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Getting to Know the GB2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
On the Floor Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Buried Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10
INSTALLATION GUIDE
GB2 35/50 GPM Grease Interceptor for Indoor Use
913-951-3300 | schierproducts.com
© Copyright 2023 Schier Products Company, 01/01/23
LIFETIME GUARANTEED GREASE INTERCEPTORS

Schier | GB-2 Installation Guide
page 2 of 10
When Installing Interceptor Inside
SPECIAL PRECAUTIONS
Installation Instructions
Hydrostatic Slabs (or Pressure Slabs)
High Temperature Kitchen Water
concrete slab subject to hydrostatic pressure
watertight
concrete
vault
InterceptorInterceptor
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
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).
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.
If your dishwashing sink(s)
discharges into a floor
drain/sink (drain), you must
regulate the flow into the drain
to avoid an overflow of water
onto the kitchen floor. This can
be done by installing a valve or
flow restriction cap on the sink
piping that discharges into the
drain. See drawing for
guidance. For detailed
guidance on indirect connections, go to:
webtools.schierproducts.com/Technical_Data/Indirect_Connections.pdf
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.
ODOR ALERT!
Do not install air
gap on outlet side
of interceptor.
Fernco or similar rubber
flow restriction end cap
installation
instructions
inside

Schier | GB-2 Installation Guide
page 3 of 10
InterceptorInterceptor
SPECIAL PRECAUTIONS
Install unit on solid, level surface in
contact with the entire footprint of unit
base; for suspended installations design
trapeze to support the wet weight of the
unit. Do not partially support unit or
suspend unit using metal U-channel to
create a trapeze.
Fully Support Base of Unit
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.
Support Inlet and Outlet Piping
DO NOT
COMPACT
BACKFILL
For Schier Grease Interceptor Installations - Failure to follow this guidance voids your
warranty
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. Models GB-50, GB-75, and GB-250 use model AK1 anchor kit.
Model GB-500 uses model AK2 anchor kit for use with deadmen anchors. Models
GB-1000, GGI-750 and GGI-1500 use model AK3 anchor kit for use with deadmen
anchors.
max water table height for
direct burial
pipe supports
InterceptorInterceptor
InterceptorInterceptor
concrete floor
suspended installation
Flush-to-Grade Burials
Flush-to-Grade buried installations (without a
riser) are not recommended for heavy foot
trac areas without the use of an internal
gusset support kit SGK2 (for GB2) or SGK3
(for GB3).
InterceptorInterceptor

GETTING TO KNOW THE GB2
Schier | GB-2 Installation Guide
page 4 of 10
1
7
12
13
10
14
15
11
9
8
9
10
16
17
7
19
9
10
6
20
14
21
18
13
12
8
9
10
2
3
4
5
6
1. Cover
2. Standard Installation Flow
Control Cartridge
3. 35 GPM Flow Control Extension
(>5' below kitchen only)
4. 50 GPM Flow Control Extension
(>5' below kitchen only)
5. Inlet Diuser (Top)
6. Diuser Retaining Nuts (x2)
7. 4" Cleanout Plugs (x2)
8. Optional Side Outlets 4" FPT (x2)
9. Connection Fitting Gaskets (x4)
10. Bulkhead Connection
Retaining Nuts (x4)
11. Inlet 4" FPT Connection
12. 3" Plain End Fittings (x2)
13. 4" Plain End Fittings (x2)
14. Diuser Foot Retaining Nuts (x2)
15. Inlet Diuser (Foot)
16. Cover Bolts (x4)
17. Cover Gasket
18. Air Relief/Visual Access
19. Outlet 4" FPT Connection
20. Outlet Diuser (Top)
21. Outlet Diuser (Foot)

Special Precautions
Install interceptor as close as possible to
fixtures being served
2
ODOR ALERT!
Do not install air
gap on outlet side
of interceptor.
1ODOR ALERT!
Interceptor is not a sewer gas
trap. All upstream fixtures must be
trapped
3
ON THE FLOOR INSTALLATION
Provide at least 5-1/2" clearance
above unit for routine
maintenance.
5-1/2" min.5-1/2" min.
4
2 Set Up Outlet Diuser and Install Cleanout Plugs
Cap all
connection
points with 4"
cleanout plugs using
pipe thread sealant or tape approved for
use with plastics.
Remove cover and fill with
water to just above the
highest connection. For riser
system testing (if required) fill to
finished grade level. CAUTION:
Support risers before filling to
prevent tipping. Inspect unit, connections and gaskets
for leaks. Check water level at specific time intervals
per local code.
1a 1b Leak?
Call customer
care at 913-951-3300
8a – 5p M – F CST
1 Test Tank for Water Tightness
Cap all unused
connection points with
4" cleanout plugs using
pipe thread sealant or
tape approved for use
with plastics.
2a Choose outlet location.
Side outlet
2c2b 2d
Unscrew diuser retaining
nut and remove outlet
diuser.
Unscrew diuser foot
retaining nut and remove
outlet diuser foot.
2f
Straight-through
2e
Insert diuser into chosen outlet and
hand tighten retaining nut.
Rotate diuser
toward chosen
outlet, replace foot
ensuring it will point
to the back wall of
the unit and hand
tighten foot retaining
nut.
Schier | GB-2 Installation Guide
page 5 of 10

ON THE FLOOR INSTALLATION
3 Calibrate Flow Control
Note to Plumbing Inspector This
interceptor includes certified internal flow
control and does not require a dedicated “Flow
Control Vent” (air intake).
3c1 3c2
Slide flow control cartridge into top of inlet diuser and rotate clockwise until
cartridge drops onto flow control retainer pins. Continue rotating clockwise until
pins are fully seated.
flow control retainer
pin
cartridge receiver
slot
3a1 3a2
Rotate flow control cartidge counter-clockwise to
release and remove from inlet diuser
Figure 1
OROR
AA
3b Depending on which flow rate is desired,
attach either the 35 or 50 GPM Flow
Control Cartridge Extension using PVC
primer/cement. Make sure extension is
fully inserted into the cartridge and hold
both components firmly together (until
cement grabs) to prevent push-out.
OR
35 GPM 50 GPM
• If dimension s 5 feet or less discard
red extension parts, then
go to Step 4.
• If dimension is greater than 5 feet
follow Steps below.
Schier | GB-2 Installation Guide
page 6 of 10

Choose inlet and outlet fittings (included) based
on pipe size.
4 Connect Piping
4" FPT4" FPT
3" PE
4" PE
4a
ON THE FLOOR INSTALLATION
5 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!
1Leak? Call customer care at
913-951-3300
8a – 5p M – F CST
4b
Connect piping using pipe thread sealant or tape approved for
use with plastics. Ensure all upstream fixtures are trapped. Vent
per local code.
4b2
4b3
Next to Sink
5-1/2" min.
Under Sink
Floor Below
4b1
OR
OR
Schier | GB-2 Installation Guide
page 7 of 10

Install interceptor as close
as possible to fixtures being
served
2 Risers (25") Max Max Water Level
Risers are not designed
to retain water
1 2 3
BURIED INSTALLATION
Special Precautions
2 Set Up Outlet Diuser and Install Cleanout Plugs
Cap all
connection
points with 4"
cleanout plugs using
pipe thread sealant or tape approved for
use with plastics.
Remove cover and fill with
water to just above the
highest connection. For riser
system testing (if required) fill to
finished grade level. CAUTION:
Support risers before filling to
prevent tipping. Inspect unit, connections and gaskets
for leaks. Check water level at specific time intervals
per local code.
1a 1b Leak?
Call customer
care at 913-951-3300
8a – 5p M – F CST
1 Test Tank for Water Tightness
Cap all unused
connection points with
4" cleanout plugs using
pipe thread sealant or
tape approved for use
with plastics.
2a Choose outlet location.
Side outlet
2c2b 2d
Unscrew diuser retaining
nut and remove outlet
diuser.
Unscrew diuser foot
retaining nut and remove
outlet diuser foot.
2f
Straight-through
2e
Insert diuser into chosen outlet and
hand tighten retaining nut.
Rotate diuser
toward chosen
outlet, replace foot
ensuring it will point
to the back wall of
the unit and hand
tighten foot retaining
nut.
Schier | GB-2 Installation Guide
page 8 of 10

Excavate hole 6" larger than interceptor on all sides. Add crushed aggregate (approximately 3/4" size rock or sand, with
no fines) to base of hole.
4a 4b
6" or more
6"
6"
6"
BURIED INSTALLATION
4 Excavation
3d
OPTIONAL: For easy flow
control 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
flow control cartridge using
PVC primer/cement.
3 Calibrate Flow Control
Note to Plumbing Inspector This
interceptor includes certified internal flow
control and does not require a dedicated “Flow
Control Vent” (air intake).
3c1 3c2
Slide flow control cartridge into top of inlet diuser and rotate clockwise until
cartridge drops onto flow control retainer pins. Continue rotating clockwise until
pins are fully seated.
flow control retainer
pin
cartridge receiver
slot
3a1 3a2
Rotate flow control cartidge counter-clockwise to
release and remove from inlet diuser
Figure 1
AA
3b Depending on which flow rate is desired,
attach either the 35 or 50 GPM Flow
Control Cartridge Extension using PVC
primer/cement. Make sure extension is
fully inserted into the cartridge and hold
both components firmly together (until
cement grabs) to prevent push-out.
OR
35 GPM 50 GPM
• If dimension is 5 feet or less
go to Step 4.
• If dimension is greater than 5 feet
follow Steps below.
Schier | GB-2Installation Guide
page 9 of 10

Set interceptor and connect piping using pipe thread sealant
or tape approved for use with plastics. Vent per local code.
Fill tank with water so that it remains in place during backfill.
5b5a
Floor Sink Installation
Fernco or similar rubber
flow
restriction end cap
InterceptorInterceptor
If your dishwashing sink(s) discharges into a floor drain/sink (drain), you
must regulate the flow into the drain to avoid an overflow of water
onto the kitchen floor. This can be done by installing a valve or flow
restriction cap on the sink piping that discharges into the drain.
5 Connect Piping
7a1
Below Grade with Riser (preferred): See instructions included with
FCR1 riser. Backfill evenly around tank using crushed aggregate
(approximately 3/4" size rock or sand, with no fines), finish with a
minimum 4" thick concrete pad.
7a2
4" min. concrete
pad
Backfill1,000 lb.
max load
Tile
7 Backfill and Finished Grade
OR
OR
Flush-to-Grade Burials:
Not recommended for heavy foot trac
areas without the use of an internal support system SGK2
(sold additionally). Contact Customer Care for more details.
Backfill evenly around tank using crushed aggregate (approximately
3/4" size rock or sand, with no fines), finish with a minimum 4" thick
concrete pad.
WARNING!
BURIED INSTALLATION
Choose inlet and outlet fittings (included)
based on pipe size.
6 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!
1Leak? Call customer care at
913-951-3300
8a – 5p M – F CST
4" min. concrete
pad
Backfill450 lb.
max load
Tile
4" FPT4" FPT
3" PE
4" PE
Schier | GB-2 Installation Guide
page 10 of 10