150
150
9.46
300
136
Frequently Asked Questions
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Frequently Asked Questions
Following are just a few of the common terms and questions we receive regarding
Grease Management.
How do I size a Grease Interceptor correctly?
A grease interceptor can be sized using two primary methods - Flow rate or capacity
Sizing by Flow Rate
Table A - Procedure for Sizing Grease Interceptors
STEP
FORMULA
EXAMPLE
1
by multiplying length x
width x depth
A sink 24” long by 20” wide by 12” deep.
Cubic content: 24 x 20 x 12 = 5,760 cu in
(61.0 x 50.8 x 30.48 cm
3
)
2
Determine capacity in gallons.
1 gallon = 231 cu in
Contents in gallons:
5,760 / 231 = 24.9 gallons
(94,451.42 / 1,000 = 94.45 litres)
3
Determine actual drainage load.
with water as the items being washed displace about 25% of
Actual drainage load:
.75 x 24.9 = 18.7 gallons
(0.75 x 94.45 = 70.84 litres)
4
In general, good practice dictates a one minute drainage peri-
od; however, where conditions permit, a two minute drainage
Flow rate = Actual Drainage Load
Drainage Period
(70.84 / 1 min. = 70.84 l.p.m.)
(70.84 / 2 min. = 35.42 l.p.m.)
5
Select Interceptor.
falls between two sizes, select the larger of the two
interceptors.
For a one minute drainage period:
For a two minute drainage period:
Table B -Metric conversions based on PDI sizes
PDI Size
4
7
10
15
20
25
35
50
75
100
Flow Rate US Gallons per Minute (gpm)
4
7
10
15
20
25
35
50
75
100
Flow Rate Liters per Second (L/Sec)
.25
.44
.63
.95
1.26
1.58
2.20
3.16
4.74
6.3
Grease Capacity Min. (lb)
8
14
20
30
40
50
70
100
150
200
Grease Capacity Min. (kg)
3.63
6.35
9.07
13.61
18.14 22.68
31.75
45.36
68
91
Interceptor is considered mandatory.
second (L/Sec).
Fixture Capacity:
Most commonly used and recommended method for Hydromechanical Grease Interceptors. This
wastewater through the interceptor. Units are expressed in Gallons Per Minute (gpm).
20gpm Grease Interceptor.
Pipe Size:
Pipe
Diameter
Maximum
Flow Rate
(gpm)
Size of interceptor
1-minute drain
period (gpm)
Size of interceptor
2-minute drain period
(gpm)
2-inch
20
20
10
3-inch
60
75
35
4-inch
125
150
75
For additional Sizing Tools and
Maintenance Interval Optimization,
use our Endura® Calculator online or
email:
