Schier GB3-CT User manual

Contents
Special Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Getting to Know the GB3-CT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
On the Floor Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Buried Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9
Part #: 057-1271-05
Find these instructions online at: schierproducts.com/gb3-ct
INSTALLATION GUIDE
GB3-CT 50 GPM Super-Capacity Grease Interceptor for Indoor Use

Fernco or similar
rubber flow
restriction end cap
When Installing Interceptor Inside
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
SPECIAL PRECAUTIONS
For Schier Grease Interceptor Installations - Failure to follow this guidance voids your warranty
Fully Support Base of Unit
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
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.
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.
High Temperature Kitchen Water
If water is entering the interceptor at excessive temperature (over
140º F), a drain water tempering valve (DTV) and approved backflow
prevention assembly must be installed. Most state and local plumbing
codes prohibit water above 140º F being discharged into the sanitary
sewer. Water above 140º 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).
pipe supports
Interceptor
Interceptor
Interceptor
Interceptor
Interceptor
Interceptor
concrete floor
suspended installation
Interceptor
Interceptor
Interceptor
Interceptor
Interceptor
Interceptor
cold water supply line
high temperature effluent ( > 140º F)
approved backflow prevention assembly
DTV (drain water tempering valve)
directly connected indirectly connected
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!
Flush-to-Grade Burials
Flush-to-Grade buried installations
(without a riser) are not recommended
for heavy foot traffic areas without the
use of an internal gusset support kit
SGK2 (for GB2) or SGK3 (for GB3).
installation
instructions
inside
Page 2 of 9
GB3-CT Installation Guide

GETTING TO KNOW THE GB3-CT
Page 3 of 9
GB3-CT Installation Guide
1
6
11
9
12
13
10
8
7
8
9
14
15
6
17
8
9
6
18
12
19
16
11
7
8
9
4
5
1. Cover
2. Standard Installation Flow
Control Cartridge
3. 50 GPM Flow Control Extension
(>5' below kitchen only)
4. Inlet Diffuser (Top)
5. Diffuser Retaining Nuts (x2)
6. 4" Cleanout Plug (x2)
7. Optional Side Outlets 4" FPT (x2)
8. Connection Fitting Gaskets (x4)
9. Bulkhead Connection
Retaining Nuts (x4)
10. Inlet 4" FPT Connection
11. 4" Plain End Fittings (x2)
12. Diffuser Foot Retaining Nuts (x2)
13. Inlet Diffuser (Foot)
14. Cover Bolts (x4)
15. Cover Gasket
16. Air Relief/Visual Access
17. Outlet 4" FPT Connection
18. Outlet Diffuser (Top)
19. Outlet Diffuser (Foot)
3
2

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
Page 4 of 9
GB3-CT Installation Guide
Provide at least 5-1/2"
clearance above unit for
routine maintenance.
5-1/2" min.
5-1/2" min.
5-1/2" min.
4
2 Set Up Outlet Diffuser 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 diffuser
retaining nut and
remove outlet diffuser.
Unscrew diffuser foot
retaining nut and remove
outlet diffuser foot.
2f
Straight-through
2e
Insert diffuser into chosen outlet
and hand tighten retaining nut.
Rotate diffuser
toward chosen
outlet, replace
foot ensuring it will
point to the back
wall of the unit
and hand tighten
foot retaining nut.

ON THE FLOOR INSTALLATION
Page 5 of 9
GB3-CT Installation Guide
3c1 3c2
Slide flow control cartridge into top of inlet diffuser 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 diffuser
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).
Figure 1
OR
OR
OR
A
A• If dimension is 5 feet or less
go to Step 4.
• If dimension is greater than 5
feet follow Steps below.
3b Attach the 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.
50 GPM

Choose inlet and outlet fittings (included)
based on pipe size.
4 Connect Piping
4" FPT
4" FPT
4" FPT
4" PE
4a
ON THE FLOOR INSTALLATION
Page 6 of 9
GB3-CT Installation Guide
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

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
Page 7 of 9
GB3-CT Installation Guide
Special Precautions
2 Set Up Outlet Diffuser 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 diffuser
retaining nut and
remove outlet diffuser.
Unscrew diffuser foot
retaining nut and remove
outlet diffuser foot.
2f
Straight-through
2e
Insert diffuser into chosen outlet
and hand tighten retaining nut.
Rotate diffuser
toward chosen
outlet, replace
foot ensuring it will
point to the back
wall of the unit
and hand tighten
foot retaining nut.

BURIED INSTALLATION
Page 8 of 9
GB3-CT Installation Guide
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"
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 diffuser 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 diffuser
Figure 1
A
A• If dimension is 5 feet or less
go to Step 4.
• If dimension is greater than 5
feet follow Steps below.
3b Attach the 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.
50 GPM

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
Interceptor
Interceptor
Interceptor
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
OR
Flush-to-Grade Burials:
Not recommended for heavy foot traffic
areas without the use of an internal support system SGK3
(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
Page 9 of 9
GB3-CT Installation Guide
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" FPT
4" FPT
4" FPT
4" PE