J a y R . S m i t h M f g . C o .

P.O. Box 3237Mon tgomery,

AL 36109-0237Tel:334-277-852 0Fax: 334-272-73 9 6www.jrsmith.com

T r a d i t i o n a l G . I .

S e m i - A u t o m a t i c D r a w - o f f G . I .

C u s t o m M a d e , S p e c i a l

Q u o t e , I n t e r c e p t o r s

G u i d e T o I n t e r c e p t i o n

2

THE TRADITIONAL GREASE INTERCEPTOR 8000 SERIES

OverviewThe Traditional grease interceptor line is thecornerstone product of the Pioneering concept.For more than fifty years, Jay R. Smith Mfg.Co. has conducted hundreds of tests, in thelaboratory and in the field, in order to offerthe most efficient Grease Interceptors withimproved operational characteristics suitablefor most applications. The Traditional GreaseInterceptor is designed for practicalapplications. These interceptors bear thecertification seal of the Plumbing andDrainage Institute (PDI). Rating, sizing andspecial features of these units can be foundin the Smith Yellow Pages® Catalog, 8000Series Interceptors. The Traditional line maybe installed either on-grade, semi-recessedor fully recessed in the floor. In addition,the fully recessed installations have theoption of a partially or completely enclosedcradle to act as a drip pan.

When to Use the Traditional UnitThe Traditional Grease Interceptor is recom-mended for areas where the accumulationof grease, fat, oil or other similar line-cloggingcontaminants should be prevented fromentering the drainage line. The TraditionalGrease Interceptor should always beconsidered when designing the plumbingdrainage system in any restaurant, cafeteria,hotel, school, hospital, institutional orcommercial building as well as foodprocessing plants, dairies and other industrieshaving facilities for the preparation andserving of food in quantity. In these installa-tions, where grease and fats are by-products,an efficient Smith interceptor should beinstalled to prevent this material fromentering the drainage line.

MaintenanceEven the best designed interceptors that areproperly installed will fail if they are notmaintained. Maintenance must be performedbefore the grease in the waste water downstream of the interceptor exceeds 100 partsper million (100 milligrams per liter) or inaccordance with local code*. If user mustcomply with a code which limits greaseto 100 parts per million, cleaning isrecommended every 2 or 3 days. Whencleaning is performed, it should beunderstood to always include the removalof grease from the top of the separationchamber as well as any solids which haveaccumulated along the bottom. See Figure 1.

*See PDI Guide to Grease Interceptors, Eliminating

the Mystery, page 8 for greater detail on maintenance.

How the Traditional GreaseInterceptor WorksThe Traditional Grease Interceptor has anexternal flow control fitting properly sizedand installed to regulate the flow intothe unit. This allows the grease-ladenwater to enter at a controlled rate of flow,free of turbulence. The water interacts withstrategically located baffles to separate thegrease from the water. Once separated, thegrease contaminants rise to the surface ofthe water in the unit by natural flotation andare accumulated until removed. A regularmanual cleaning interval must be establishedfor maintaining proper discharge efficiency.

Traditional Interceptor GuideSpecificationThe Traditional Grease Interceptor, whichis often referred to as a passive or manualunit, utilizes the gravity separationprinciple. The rate of flow into theinterceptor is controlled by a flow controlfitting, enabling the interceptor to collectover 90% of the grease which flows intoit. “Uni-lock” cover design permitsconvenient cover removal for periodiccleaning. The interceptor maybe set on the floor, semi-recessed orrecessed with cover flush with finishedfloor. Low rough-in designs are availablefor use with low roughing sinks. The unitis constructed from gray duco coatedfabricated steel complete with removablebaffles, gasketed cover, external flowcontrol fitting, internal air relief by-pass,cleanout plug and visible double walltrap seal. Available options include lift outsediment bucket and aluminum cover orcover recessed for terrazzo or tile. Theseunits may also be fabricated from type304 stainless steel.

FIGURE 1: Grease Interceptor Cleaning And Maintenance

• Remove cover.• Inspect Interceptor.• Remove grease (FOG) from top of separation chamber.• Remove any solids from bottom of chamber.• Make certain all passages, including air relief, are clear of obstructions.• Check integrity of baffles and

make sure they are in place.• Check cover gasket for any

damage. Replace if necessary.• Reinstall cover.• Tighten cover hold down

apparatus.StaticWater Line

Lock and Lift Ring

Non-Skid Cover

FlowControl

OutletNeoprene Gasket

Air Relief

RemovableBaffles

Cleanout

SeparationChamber

Inlet

Figure 1

3

TRADITIONAL GREASE INTERCEPTOR W/SEMI-AUTOMATICDRAW-OFF 8000GT SERIES

OverviewSmith “GT” Series Semi-Automatic Draw-offGrease Interceptors offer the sameintercepting efficiency as the Traditionalmanually cleaned models, but minimize theeffort involved in the unsanitary andundesirable job of removing the accumulatedgrease manually.

The Semi-Automatic Draw-offInterceptor eliminates:• Cover removal and• Manually removing accumulated

grease.

Since cleaning a “GT” interceptor is simple,fast and efficient, maintenance personnelwill more likely follow the regular cleaningschedule. This is a distinct advantage overthe Traditional units which are frequentlyleft unattended. The Semi-AutomaticDraw-off Grease Interceptors aredesigned for floor mount installation.

When to Use the Semi-Automatic UnitThe Semi-Automatic Draw-off GreaseInterceptor is recommended for areaswhere a regular cleaning schedule isdifficult to maintain, and when no one wantsto deal with removing the accumulatedgrease from a Traditional GreaseInterceptor. The Semi-Automatic Draw-offGrease Interceptor makes it easy formaintenance personnel to extract grease,fat, oil, or other similar line-cloggingcontaminants that would otherwise enter thedrainage line. Like the Traditional GreaseInterceptors, the Semi-Automatic Draw-off isideal for plumbing drainage

systems in any restaurant, cafeteria, hotel,school, hospital, institutional or commercialbuilding, or food processing plant havingfacilities for preparing and serving food inquantity. The frequency of the draw-offcycle is determined by the use load factorof the interceptor. The cleaning cycle can beset after the unit is in operation forseveral weeks. By observing the amountof grease collected and the frequency ofuse, the operator can determine a practicalcleaning cycle.

How the Semi-AutomaticInterceptor Works1. Unit in normal use has the line shut-off

valve open and draw-off valve closed.When cleaning is required*, run a fullstream of hot water through interceptor.It is preferable to have this water at140° or higher, running for a period ofat least two minutes.

2. Turn off hot water running into theinterceptor and wait for a period ofthree to five minutes for the grease toliquefy.

3. Draw-off cycle can now be started.Close the line shut-off valve (A).

4. Open draw-off valve (B) at top of theinterceptor and place a containerunderneath this valve. Run hot waterthrough interceptor at a rate between1-1/2 and 2-1/2 G.P.M.

5. After water has run into interceptor atthis rate for a short period, the unit willfill. Accumulated liquefied grease willbe raised into cone (C) and draw-offpiping.

6. Allow accumulated liquefied grease to flow out of draw-off valve until clearwater appears.

7. When clear water appears, shut off flowof hot water into interceptor, turn lineshut-off valve to open position.

8. Close draw-off valve at top of interceptor.9. Interceptor at this stage is ready again

for normal use.

“GT” Series Semi-AutomaticDraw-Off Grease Interceptor GuideSpecificationThe “GT” Series Semi-Automatic Draw-OffGrease Interceptor utilizes the gravityseparation principle along with a uniquesemi-automatic draw-off design whichpermits removal of accumulated greasewithout cover removal. The rate of flow intothe interceptor is controlled by a flowcontrol fitting enabling the interceptor tocollect over 90% of the grease which flowsinto it. Cover and Grease Accumulating Conedesign permits fast removal of accumulatedgrease during established cleaning intervals.Low rough-in designs are available for usewith low roughing sinks. The unit isconstructed from gray duco coatedfabricated steel complete with greaseaccumulating cone, line shut-off valve,draw-off valve, removable baffles, gasketedcover, external flow control fitting, internalair relief by-pass, cleanout plug and visibledouble wall trap seal. These interceptorsmay also be fabricated from type 304stainless steel.

Grease AccumulatingCone (C)

G-Cleanout

Air Relief

RemovalBaffles

Line Shut-offValve (A)

INLET

Static WaterLine

OUTLETDraw-OffValve (B)

Separation Chamber

4

CUSTOM MADE, SPECIAL QUOTE, INTERCEPTORS

OverviewWhen a job specification or constructionproject requires an interceptor to do morethan just prevent fat, oil, and grease (FOG)from entering the city’s sanitary sewersystem, Jay R. Smith Mfg. Co. offers a varietyof interceptors to meet your specific needs— from the innovative Remediator®Grease Treatment System, as well as a varietyof specialty interceptors.

Speciality EngineeringFor a complete line of specialty interceptors,look to Jay R. Smith Mfg. Co. Our in-housestaff of engineers possess the technicalknowledge to confer with engineers andcontractors to design an interceptor to meeta special application, product modification,or installation need. We look forward to thechallenge of designing and manufacturingspecial products which solve our customer’sneeds. No cookie cutter approach here, ourdesigns are customer specified to get the jobdone.

Speciality InterceptorsOur full line of interceptors aredesigned for adaptability, conformanceto code, ease of installation, andmaximum performance efficiency. Some of the speciality interceptorsavailable from Jay R. Smith Mfg. Co.:

• Fish Scale Interceptor, SQ-8-1164 • Slurry/Pulper Waste Retention

Interceptor, SQ-8-1637 • Animal Fur/Hair Interceptor,

SQ-8-2180 • Sand Sump with Solids Interceptor,

SQ-8-1099 • Solids Interceptors, 8700 Series • Sand Interceptors, 8800 Series • Lint and Sediment/Oil Interceptors,

8900 Series

Custom Made, Special Quote,ProductsWe have more than 77 years of experi-ence in designing new products to meetunusual specification requirements forparticular jobs.

The Jay R. Smith Mfg. Co. “SpecialQuote Products” job studies binderholds a wealth of products solutions fora variety of installation needs. To ordera copy or to talk about your specrequirements, please contact your localrepresentative or us at www.jrsmith.com

Secured Gasketed Cover Made From 3/16 (5) Diamond Plate

Lift Ring

Optional (2) 2" (51) Vent Connections

Anchor Flange (When Specified)

Removable Secondary Screen

OUTLET

Offset (By Others)

INLET

StaticWaterLine

Suggested Piping Arrangement (By Others)

Removable Stainless Steel Mesh Bucket

Featured Product: SQ-8-2180,Animal Fur/Hair Interceptor -10, 20, 25, and 50 g.p.m.

Problem: A major pet store chainprovides complete grooming facilities.The washing and trimming of the ani-mals create excessive animal furresulting in continuous stoppages inthe building sewer.

Goal: Provide an interceptor that willretain the majority of the animal furalong with a removable sedimentbucket.

Solution: An interceptor is designedto accommodate the flow along withthe anticipated quantity of fur. Asediment bucket constructed ofstainless steel framing and mesh wassupplied to meet the requirementfor a durable and non-corrodiblematerial. A secondary screen wasalso included between the bucket andthe outlet.

Result: The stoppage in the buildingsewer was resolved. This unit may alsobe suitable for applications includingveterinary clinics, kennels, beautysalons, and barber shops, whereverfur/hair may present a problem.

SQ-8-2180, Animal Fur/Hair Interceptor

TABLE 5

The recommendations for sizing,installation and maintenance of greaseinterceptors contained in this sectionare based on experience of the industryand were taken from PDI-G101.

Sizing ConsiderationsA grease interceptor conforming toStandard PDI-G101 is designed andcertified to operate efficiently at its ratedcapacity. The larger the interceptor thehigher the flow rate it will handle efficientlywith a greater quantity of grease retainedbefore cleaning is required. While a smallinterceptor, undersized, can accommodatea flow of waste water well in excess of itsrated capacity, it will not intercept greaseefficiently under such overload conditions.

Fixture drainage period, incombination with the service requiredand the quantity of waste water involved,establishes the rate of flow through thegrease interceptor. Flow rate is thereforethe primary gauge which establishesinterceptor size or capacity.

The link between flow rate anddrainage load to produce satisfactorygrease interceptor operation is a FlowControl Fitting. Without it, a correctly sizedgrease interceptor will not regulate the flowof water discharged from the fixture it isserving. Therefore, to ensure that the flowrate does not exceed the greaseinterceptor’s rated capacity, a flow controlfitting is essential for protection againstoverloading the grease interceptor whichcould occur from sudden surges from thefixture. The flow control fitting will controlthe flow of waste water at all times,enabling the interceptor to operate at itscertified capacity.

Size SymbolsIt has been determined through the testingand rating procedure that eight (8)different sized grease interceptors arerequired for normal domestic, commercial,and institutional installations. These sizesare based on certification standard flow

rates and grease retention capacity ratingsfor grease interceptors, see Table 1. Table 2 lists the PDI size symbol for eachof the standard rated grease interceptors.

Sizing ProcedureTable 3 is provided to show the standardformula in steps for sizing greaseinterceptors to suit requirements ofspecific fixtures.

SelectionTable 4 is included as a selection chart forstandard PDI Certified grease interceptorsapplicable to various size fixtures commonlyused in domestic, commercial andinstitutional installations. The selectionslisted are based on the sizing formulacovered in Table 3.

DishwashersA separate grease interceptor is recom-mended for each commercial dishwasher.The size of the interceptor is determined bythe GPM discharge rate of the dishwasher.Select proper interceptor of equivalent ornext higher rate from Table 2.

Multiple FixturesWhen multiple fixtures are served by asingle interceptor, calculate the totalcapacity of all fixtures, establish themaximum number of fixtures that maybe drained simultaneously and apply thisfactor to the total capacity to determinethe maximum simultaneous capacity. Then proceed with sizing and selection ofinterceptor using sizing formula, Table 3.

Alternate Sizing Method Based onDrainage Fixture-UnitsMost plumbing codes list drainage Fixture-Unit values for plumbing fixtures and forfixtures not listed, these values are given fordrain outlet or trap size. Fixture-Unit valuesare converted to discharge rates on thebasis of one Fixture-Unit equaling 7.5 GPM.See Table 5 for recommended PDI sizegrease interceptor based on drainageFixture-Unit sizing method.

SIZING INTERCEPTORS ACCORDING TO PDI STANDARD PDI-G101

Determine cubic content offixture by multiplyinglength X Width X depth.

Determine capacity in gallons. 1 gal. = 231 cubic inches

Determine actual drainageload. The fixture is normallyfilled to about 75 % of capac-ity with water. The itemsbeing washed displace about25 % of the fixture content,thus actual drainage load =75% of fixture capacity

Determine flow rate anddrainage period. In general,good practices dictate a one(1)minute drainage period; how-ever, where conditions permit,a two (2) minute drainageperiod is acceptable. Drainageperiod is the actual time requiredto completely drain the fixture.

Flow rate = Actual Drainage Load

Drainage Period

Select interceptor. FromTable 2 select interceptorwhich corresponds to theflow rate calculated. Note:Select next larger size whenflow rate falls between twosizes listed.

18 X 12 X 6 1 4.2 7 4

16 X 14 X 8 1 5.8 7 4

20 X 18 X 8 1 9.4 10 7

18 X 16 X 8 2 15.0 15 10

20 X 18 X 8 2 18.7 20 10

30 X 20 X 8 1 15.5 20 10

24 X 20 X 12 1 18.7 20 10

22 X 20 X 8 2 23.0 25 15

22 X 20 X 12 2 34.0 36 20

24 X 24 X 12 2 44.9 50 25

1-1/4 1 7.5 101-1/2 2 15.0 152 3 22.0 252-1/2 4 30.0 353 5 37.5 504 6 45.0 50

PDI Size Symbol 4 7 10 15 20 25 35 50Flow Rate GPM 4 7 10 15 20 25 35 50

L/s .25 .44 .63 .95 1.26 1.58 2.20 3.16Grease CapacityPounds 8 14 20 30 40 50 70 100

KG 3.6 6.4 9.1 13.6 18.2 22.7 31.8 45.4

TABLE 2: SIZING AND RATING

TABLE 3: PROCEDURE FOR SIZING GREASE INTERCEPTORS(Metric Equivalents Omitted for simplicity)

A sink 48” long by 24”wide by 12” deep. Cubiccontent 48 X 24 X12=13,824 cubic inches

Contents in gallons13,824/231 = 59.8 gallons

Actual drainage load

.75 X 59.8 = 44.9 gallons

Calculate flow rate for one-minute period

44.9/1 = 44.9 GPM Flow Rate

Two-minute period

44.9/2 = 22.5 GPM Flow Rate

For one-minute period -44.9 GPM requires PDI size “50”

For two-minute period -22.5 GPM requiresPDI size “25”

Steps Formula Example

1

2

3

4

5

TABLE 4: SELECTION CHART(Metric Equivalents Omitted for Simplicity)

FixtureCompartmentSizes (Inches)

No. ofCompart-ments

DrainageLoad(Gallons) One-Minute

Drainage Period

Fixture Outlet or TrapSize (Inches)

PDI Size Grease Interceptor

GPMEquivalent

Drainage Fixture-Unit Value

Two-MinuteDrainage Period

Recommended PDI SizeGrease Interceptor

For Small 4 0.25 8 3.6 10.0 37.9Domestic Use 7 0.44 14 6.4 17.5 66.2

10 0.63 20 9.1 25.0 94.6For Large 15 0.95 30 13.6 37.5 141.9Domestic, 20 1.26 40 18.2 50.0 189.3Commercial, and 25 1.58 50 22.7 62.5 236.6Institutional Use 35 2.20 70 31.8 87.5 331.2

50 3.16 100 45.4 125.0 473.1

TABLE 1: CERTIFICATION STANDARD FLOW RATES AND GREASE RETENTION CAPACITY RATINGSFOR GREASE INTERCEPTORS

Flow Rate

(GPM) (L/s)

Grease RetentionCapacity Rating

(Pounds) (kg) (Gallons) (L)

Recommended MaximumCapacity of Fixtures Connected

Connected to Interceptors

5

JAY R.SMITH MFG. CO.DIVISION OF SMITH INDUSTRIES, INC.POST OFFICE BOX 3237MONTGOMERY, ALABAMA 36109-0237 (USA)TEL: 334-277-8520 FAX: 334-272-7396 www.jrsmith.comCUSTOMER

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ASPE

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Contact your local representative

G u i d e t oI n t e r c e p t i o n

Traditional G.I.

Semi-Automatic Draw-off G.I.

Custom Made, SpecialQuote, Interceptors