Schier GB-250-250HF User manual

© Copyright 2020 Schier, 03/31/2020
Contents
Special Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Getting to Know the GB-250-250HF . . . . . . . . . . . . . . . . . . . . . . . . 4
Buried Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
On the Floor Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-13
Installation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
INSTALLATION GUIDE
GB-250-250HF 250 GPM Grease Interceptor for
Indoor/Outdoor Installation

When Installing Interceptor Inside
Fernco or
similar rubber
flow restriction
end cap
SPECIAL PRECAUTIONS
Installation Instructions
Hydrostatic/Pressure Slabs
High Temperature Kitchen Water
concrete slab subject to hydrostatic pressure
watertight
concrete
vault
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.
InterceptorInterceptor
InterceptorInterceptor
page 2 of 14
GB-250-250HF Installation Guide

SPECIAL PRECAUTIONS
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. The wet weight of the
interceptor combined with high
temperature kitchen water creates
the potential for tank deformation in
suspended installations. In these
situations Above Grade Support Kit
model AGS1 is required to be
installed to maintain GB-250
structural integrity.
Suspended Installations
Install unit on solid, level surface in contact
with the entire footprint of unit base
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
pipe supports
DO NOT
COMPACT
BACKFILL
For Schier Grease Interceptor Installations - Failure to follow this guidance
voids your warranty
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
model AK1
anchor kit
High Water Table Installations
InterceptorInterceptor
AGS1
InterceptorInterceptor
concrete floor
InterceptorInterceptor
page 3 of 14
GB-250-250HF Installation Guide

GETTING TO KNOW THE GB-250-250HF
1. Pickable Cast Iron Cover (standard)
2. Cover Gasket
3. Safety Star (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. Inlet Diffuser
8. Inlet Diffuser Retaining Nut
9. Inlet Diffuser Foot Retaining Nut
10. Inlet Diffuser (Foot)
11. Bulkhead Connection Retaining Nut
12. Bulkhead Connection Gasket
13. Inlet Bulkhead Connection 4" FPT
14. 4" Plain End Fitting (x2)
15. Composite Cover Bolts
and Washers (x8)
16. Bolted Composite Cover (optional)
17. Air Relief/Visual Access
18. Outlet Diffuser Retaining Nut
19. Outlet Diffuser
20. 4" Cleanout Plug (x4)
21. Outlet Bulkhead Connection
(optional) 4" FPT (x2)
22. Outlet Bulkhead Connection
(standard) 4" FPT
23. 7/16" Nut Driver Bit
1 15
16
2
3
4
17
18
19
20
11
12
21
11
5
6
12
21
20
2
3
5
6
7
8
9
10
11
12
13
14
23
4
11
14
12
22
page 4 of 14
GB-250-250HF Installation Guide

Special Precautions
BURIED INSTALLATION
Max Water Level
Risers are not designed
to retain water
5
Install interceptor as
close as possible to
fixtures being served
1 3
Provide at least 16"
clearance above unit for
routine maintenance.
2
16" min.
3 Risers (94") Max
4
ODOR ALERT!
Interceptor is not a
sewer gas trap.
All upstream fixtures
must be trapped
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.
Fill Line
page 5 of 14
GB-250-250HF Installation Guide

BURIED INSTALLATION
2e
Cap all unused connection points
with 4" cleanout plugs using pipe
thread sealant or tape approved
for use with plastics.
2 Set Up Outlet Diffuser and Install Cleanout Plugs
2a Choose outlet location.
Side outlet
2b 2c 2d
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.
Straight-through
page 6 of 14
GB-250-250HF Installation Guide

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, Excavate Burial Pit.
• If dimension "A" in Figure 1 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).
3 Install Flow Control
Figure 1
InterceptorInterceptor
UNITS WITH 4" DIFFUSERS
3a
4
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.
1
Remove safety star
insert and remove flow
control cartridge from
the parts bag
Install flow control plate
on the inlet bulkhead
fitting prior to connecting
piping and burial. Fasten
plate to 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.
UNITS WITH 6" DIFFUSERS
3b
2 3
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
Flow
Control
Plate
Inlet
Bulkhead
Fitting
BURIED INSTALLATION
page 7 of 14
GB-250-250HF Installation Guide

Excavate hole at least 12" larger than interceptor on
all sides and 6" 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.
4a 4b
6" or more
12" 12"
6"
4 Excavate Burial Pit
BURIED INSTALLATION
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! Have a Leak? Call customer
care at 913-951-3300
Hours 8am-5pm CST, M-F
5b
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.
5a
4" Plain End
4" FPT
Outlet
Connection
2-Way
Cleanout Tee
Inlet
Connection
page 8 of 14
GB-250-250HF Installation Guide
DETAIL
Lower unit into pit 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.
DETAIL
Drain line
Flexible Coupling
Plain End Fitting
Bulkhead Fitting

BURIED INSTALLATION
7 Bring Covers Flush-to-Grade
The GB-250-250HF is ready for burial depth of 44" from finished grade to bottom of tank (or 13-1/2" to centerline of inlet).
Deeper burials will require extending the Cover Adapters and possibly adding risers.
Measure dimension X to determine riser height needed.
7a
Install risers if required
(see instructions included with FCR2).
7b
Riser Height Risers
Needed Required
0" - 4" None (use adapter)
>4" - 34" FCR2 (x2)
>34" - 64" FCR2 (x4)
>64" - 94" FCR2 (x6)
If required, Cover Adapters
may now be tilted up to
10º in any direction using
gasket flexibility.
7f
Adjust Cover Adapter
heights as needed.
Maintain a minimum
2-1/2" insertion depth.
2-1
/
2" minimum
7d
Loosen the
Cover Adapter Upper
Band Clamp using 7/16"
Nut Driver Bit.
7c
Tighten Upper
Band Clamp to 5 -8 ft.
lbs. of torque using 7/16"
Nut Driver Bit.
7e
8 Backfill and Finished Grade
Fill unit with water for stabilization
and float-out prevention.
8a 8b
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.
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.
TOP VIEW 18"
min
45º
18"
min
18"
min
18"
min
Concrete Slab
Rebar
Pour concrete slab to finished grade.
8c
8c1
Rebar
page 9 of 14
GB-250-250HF Installation Guide

Special Precautions
Install interceptor as close as
possible to fixtures being served
3
ON THE FLOOR INSTALLATION
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.
Fill Line
ODOR ALERT!
Interceptor is not a sewer gas
trap. All upstream fixtures must
be trapped
2
ODOR ALERT!
Do not install air
gap on outlet side
of interceptor.
1
Provide at least 16"
clearance above unit for
routine maintenance.
16" min.
4
page 10 of 14
GB-250-250HF Installation Guide

ON THE FLOOR INSTALLATION
page 11 of 14
GB-250-250HF Installation Guide
2e
Cap all unused connection points
with 4" cleanout plugs using pipe
thread sealant or tape approved
for use with plastics.
2 Set Up Outlet Diffuser and Install Cleanout Plugs
2a Choose outlet location.
Side outlet
2b 2c 2d
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.
Straight-through

ON THE FLOOR INSTALLATION
3 Install Flow Control
UNITS WITH 4" DIFFUSERS
3a
4
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.
1
Remove safety star
insert and remove flow
control cartridge from
the parts bag
Install flow control plate
on the inlet bulkhead
fitting prior to connecting
piping and burial. Fasten
plate to 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.
UNITS WITH 6" DIFFUSERS
3b
2 3
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
Flow
Control
Plate
Inlet
Bulkhead
Fitting
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" in Figure 1 is greater than 13 feet,
or a high flow/increased head pressure condi-
tion 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).
Figure 1
InterceptorInterceptor
page 12 of 14
GB-250-250HF Installation Guide

FLOOR BELOW INSTALLATION DETAIL
5 Install AGS1 Above Grade
Kit (sold separately)
ON THE FLOOR INSTALLATION
Mechanically
couple inlet and
outlet drainage
lines to unit. Do not
solvent weld.
Ensure all upstream
fixtures are trapped.
Vent per local code.
The wet weight of the interceptor combined with high
temperature kitchen water creates the potential for tank
deformation in suspended installations. In these situations
Above Grade Support Kit model AGS1 is required to be
installed to maintain GB-250 structural integrity.
DETAIL
Drain line
Flexible Coupling
Plain End Fitting
Bulkhead Fitting
Above Grade Support Kit - AGS1
4 Connect Piping
vent per
local code
page 13 of 14
GB-250-250HF Installation Guide
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.
4a
4" Plain End
4" FPT
DETAIL
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! Have a Leak? Call customer
care at 913-951-3300
Hours 8am-5pm CST, M-F
4b

max water table height for direct burial
model AK1 anchor kit
InterceptorInterceptor
INSTALLATION OPTIONS
1 High Water Table Installations, See Anchor Kit Model AK1
If the installation location is in a high water table
area or at risk are (including but not limited to tidal
surge areas, floodplains and areas that receive
storm water) the GB-250-250HF must be installed
with Schier model AK1 anchor kit.
page 14 of 14
GB-250-250HF Installation Guide