Schier GB-250 User manual

Contents
Special Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Series Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Getting to Know the GB-250 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11
INSTALLATION GUIDE
GB-250 100/200 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.
pipe supports
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. Suspended installations
are typically used with a riser that
penetrates the floor above. In these
situations Above Grade Support Kit model
AGS1 is required to maintain a proper seal
of the risers on the neck of the tank. AGS1
concrete floor
DO NOT USE CAST IRON
COVERS IN ABOVE GRADE OR
INDOOR INSTALLATIONS
Use composite cover C24BC for above
grade installations
Schier | GB-250 Installation Guide
page 2 of 11

For lower flow rates and higher grease
storage requirements. Piping between
units and two-way cleanout tees by
others.
NOTE: When the flow control is required,
it should only be installed on the first unit
in the series.
Rated Grease Capacities
for Units Piped in Series
No. of Removal Eciency
Units 100 GPM 200GPM
in Series 96.7% 93.5%
2 3,790 lbs. 2,392 lbs.
3 5,685 lbs. 3,588 lbs.
4 7,580 lbs. 4,784 lbs.
Top View of 4 GB-250 Units Piped in Series
Two-way cleanout tee extended to grade
(provided by others)
Series Installations
SPECIAL PRECAUTIONS
For Schier Grease Interceptor Installations - Failure to follow this guidance voids your
warranty
Below Grade Installation Slab Requirements
A concrete slab to finished grade with rebar is required when installing
interceptor below grade.
Pedestrian Trac or
Greenspace Areas
Vehicular Trac Areas
4" min. slab 8" min. slabRebarRebar
DO NOT
COMPACT BACKFILL
MECHANICALLY
Compact by
hand only
concrete slab subject to hydrostatic pressure
watertight
concrete
vault
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.
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-250 uses model AK1 anchor kit.
max water table height for
direct burial
model AK1
anchor kit
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.
6 - 94"
6 - 94"
Installations with Risers
Max Water Level
Risers are not designed
to retain water
3 FCR2 Risers Max
94"
94"
Secure Cover Adapters
Cover adapters must be secured to
base units in above grade installations
with increased head pressure
conditions. Use cover adapter tie-down
kit model ATD1.
CA2
Schier | GB-250 Installation Guide
page 3 of 11

GETTING TO KNOW THE GB-250
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. Inlet diuser cover (white)
8. Flow control cartridge (for >13' below
kitchen, 200 GPM only), see page 7 for
more information.
9. Inlet diuser
10. Inlet diuser retaining nut
11. Inlet diuser foot retaining nut
12. Inlet diuser (foot)
13. Bulkhead connection retaining nut
14. Bulkhead connection gasket
15. Inlet bulkhead connection 4" FPT
16. 4" plain end fitting (x2)
17. Composite cover bolts
and washers (x8)
18. Bolted composite cover (optional)
19. Air relief/visual access
20. Outlet diuser retaining nut
21. Outlet diuser
22. 4" cleanout plug (x2)
23. Outlet bulkhead connection (optional) 4"
FPT (x2)
24. Outlet bulkhead connection (standard)
4" FPT
25. 7/16" nut driver bit
8
1 17
18
2
3
4
19
20
21
22
13
14
23
13
5
6
14
23
22
2
3
5
6
9
10
11
12
13
14
15
16
25
4
13
16
14
24
7
Inlet diuser
cover (white)
200 GPM
flow control
cartridge (red)
Schier | GB-250 Installation Guide
page 4 of 11

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
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.
6" or more
2 Excavate Burial Pit
12" 12"
6"
Schier | GB-250 Installation Guide
page 5 of 11

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-250 Installation Guide
page 6 of 11

This unit is supplied with additional components for use in
high flow/ increased head pressure conditions.
• If dimension "A" is 13 feet or less, no additional components
are 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.
4 Install Inlet Diuser Components
4b Install chosen component
4a Choose appropriate inlet diuser component based on flow rate and diuser size
At 100 GPM this unit is certified to ASME A112.14.3 (Type D) and CSA
B481.1 and does not require flow control. This inlet diuser cover is
provided to prevent the unit from swamping.
100 GPM
Install inlet diuser cover
(white)
At 200 GPM this unit is certified to ASME A112.14.3 (Type C) and CSA
B481.1 and requires internal flow control. External flow control with
vent not required.
200 GPM
Install flow control
cartridge (red) or plate
4" diuser 4" diuser 6" diuser
For easy inlet diuser cover or 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.
4c OPTIONAL: install extension handle
200 GPM 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 inlet diuser cover or flow control
cartridge from the parts bag. Slide chosen component 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
Any Unit with 4" Diusers
Finished installation
showing optional
extension handle
Schier | GB-250 Installation Guide
page 7 of 11

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-250 Installation Guide
page 8 of 11

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 AGS1 Above Grade Kit (sold separately)
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.
Above Grade Support Kit - AGS1
Schier | GB-250 Installation Guide
page 9 of 11

8 Bring Covers Flush-to-Grade
The GB-250 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.
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-250 Installation Guide
page 10 of 11

DO NOT COMPACT BACKFILL
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
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-250 must be installed
with Schier model AK1 anchor kit.
Max water table height for direct burial
Model AK1 anchor kit
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
TOP VIEW 18"
min
45º
18"
min
18"
min
18"
min
Concrete Slab
Rebar
Schier | GB-250 Installation Guide
page 11 of 11