AIRFLEXDisc Diffusers

Tube DiffusersMembranes

Piping & ConnectorsBlowers

F O R T H E W A S T E W A T E R I N D U S T R Y

TM

S T A M F O R DS C I E N T I F I CI N T E R N A T I O N A LI N C .

CompleteAERATIONSolutions

ABOUT

SSI

S T A M F O R D S C I E N T I F I C I N T E R N A T I O N A L I N C .

SSI is a privately held company headquartered in Poughkeepsie,

New York, USA, dedicated to the wastewater treatment industry.

We service our customers through a network of agents and

distributors in over 50 countries. Our company’s owners have played

active roles in the Aeration Business since 1991. We maintain a

drafting department with CAD ability and offer complete design

assistance to consultants and customers. Our factory trained technical

personnel are available for Start Up and Commissioning services and

Oxygen Transfer Testing. We own our own production tooling of

membranes and plastic components, and constantly strive to improve

the status-quo, whether through advanced membrane compound

development, or expanding the breadth of our product line to offer

our customers more choices. SSI manufactures premium quality disc

and tube diffusers, with a variety of membrane materials, putting us

in the unique position of being able to always

recommend the best product for

the job to our customers.

SSI is a member of the

Water Environment

Federation and is an

active participant in trade

shows around the world.

Dedicated to

protecting our

earth’s water.

Stamford Scientific International, Inc. 4 Tucker DrivePoughkeepsie, NY 12603USA845-454-8171fax: 845-454-8094www.StamfordScientific.comemail: info@stamfordscientific.com

SSIPerformance Testing

Airflow — scfm/diffuser

SOT

Ein

%p

er f

oo

t

SOT

Ein

%p

er meter

Airflow — m3/hr

OXYGEN TRANSFER-DISC & CAP

2

AFD35012” Disc

AFD2709” Disc

4 6 8 100

63 9 12 15 18 21

1%

2%

2%

4%

6%

8%

10%

SOT

Ein

%p

er meter

2%

4%

6%

8%

10%

3%

AIRFLEX CAP 127 5” Ø

SOT

Ein

%p

er f

oo

tAirflow — m3/hr

2 4 6 8 10 12 14 160

1%

2%

3%

AFT61024” x 2.6” Ø(610mm x 65mm) Ø

AFT100039” x 3.7” Ø(1000mm x 94mm) Ø

Airflow — scfm/diffuser

O X Y G E N T R A N S F E R - D I S C S

OXYGEN TRANSFER-TUBESO X Y G E N T R A N S F E R - T U B E S

SSI disc diffusers are the industry leaders in

performance and technology, as many of our

customers have learned over the years. We have

replaced our competitors’ membranes and

complete diffusers time and time again. SSI

tests oxygen transfer and headloss of all fine

bubble diffusers. Below are basic design data

from our test library. Each treatment plant is

different. Water velocity, tank size, diffuser

spacing, placement, and process can all

influence these data. Contact the factory for

more specific information on your project.

Airflow — scfm/diffuser2 4 6 8 10 12 14 16 18

Hea

dlo

ss —

in

ches

of

wat

er

0

18

16

14

12

10

8

6

4

2

0

20

Airflow — m3/hr

Head

loss —

mm

of w

ater

450

400

350

300

250

200

150

100

50

50084 12 16 20 24 28

H E A D L O S S C H A R T

Oxygen transfer per m3 and m submergenceEfficiency depends on water depth, which is not reflected in this curve

2 3 4 5 6 7 8 9 10

gO2/

m3

-hr

0

22

20

18

16

14

12

10

A I R F L E X D I S C A F D 3 5 0 E F F I C I E N C Y24

Oxygen transfer per m3 and m submergenceEfficiency depends on water depth, which is not reflected in this curve

2 3 4 5 61 7

gO2/

m3

-hr

0

22

20

18

16

14

12

10

A I R F L E X D I S C A F D 2 7 0 E F F I C I E N C Y24

AFD270

AFD350 +AFT610

AFT1000(per meter)

AIRFLEX CAP

ME

TR

IC

8 12 16 20 244

12

0.3 m2/DIFFUSER

0.5 m2/DIFFUSER

1.0 m2/DIFFUSER

0.8 m2/DIFFUSER

0.3 m2/DIFFUSER

0.8 m2/DIFFUSER

1.0 m2/DIFFUSER

0.5 m2/DIFFUSER

P R O D U C T S

AIRFLEX

DiscDiffusers

T H E S T R O N G E S T M E M B R A N E S

T H E S M A L L E S T B U B B L E S

12” discs offer cost advantages

compared to 9” discs when complete

system costs are considered, because

they require less pipe & supports, and

less installation time. It is appropriate

to consider 12” discs in any application

where the diffuser density of 9” discs

would be 7% or higher, because the

spacing of 12” discs in the tank would

in such cases be sufficient.

12” discs offer cost advantages

compared to 9” discs when complete

system costs are considered, because

they require less pipe & supports, and

less installation time. It is appropriate

to consider 12” discs in any application

where the diffuser density of 9” discs

would be 7% or higher, because the

spacing of 12” discs in the tank would

in such cases be sufficient.

We manufacture our AFD270 (9”) and AFD350 (12”) disc diffusers withcompression molded EPDM membranes. These are made with less than 10%extractable oils in the final product. Other companies may claim low extractableoil content, however SSI measures it in the final product where it tends to behigher, rather than in the base compound. Extractable oil content is importantbecause it is a determining factor in membrane shrinkage. The less extractableoil we use to make our membranes, the less they will shrink.

SSI disc membranes have Die-T test results per ASTM D624-91 of over 110pounds/linear inch. This is double that of some competitors. Die-T measurestear propagation, which is the amount of force required to continue a tear.Since we perforate our diffusers with knives, Die-T is an effective means ofdetermining the force required to tear one of our slits. Our impressive Die-T testresults allow us to use more perforations in our membranes than many of ourcompetitors. A higher density of perforations results in a more efficient diffuser.

EPDM, unlike Silicone or Polyurethane, can be compounded in hundreds ofdifferent ways, with different fillers, curatives, and percentage concentration ofbase polymer. SSI, together with our Malcolm Baldridge National Quality Awardwinning membrane factory, conducted many tests and production runs beforeselecting our premium EPDM compound. The selection was made based on theabove factors of tear resistance and oil content, but also with an eye onefficiency, which can be affected by the hydrophilic properties of the material,and on modulus, which affects the “memory” of the molded product over time.

Our plastic disc components are made of environmentally friendlypolypropylene, and are designed to seal tightly without leakage. The membranehas an integral O-ring seal which is tightly compressed by our retaining ringwhich keeps air in and water out.

13.8" / 350mm

3/4" NPT

SSI disc diffusers connect

to pipe in one of two

ways – with a proprietary

Quick Connect Bayonet

Saddle, or with a

Universal Grommet. Our

factory pre-assembled

discs install onto the

Quick Connect Saddle

with just a 1/4 turn.

AFD350 - 12” discDesign Flow 2.5-5.0 SCFM (4.2-8.3 Nm3/hr)Flow Range 0-12 SCFM (0-20 Nm3/hr) Slit quantity: 10,155

10.6" / 270mm

3/4" NPTAFD270 - 9” discDesign Flow 1.5-3.0 SCFM (2.5-5.0 Nm3/hr)Flow Range 0-7 SCFM (0-12 Nm3/hr)Slit quantity: 6,600

SSI offers two

methods to connect

tube diffusers to pipe

– with our Quick

Connect Super Saddle,

or with 304L Stainless

Steel nipples.

P R O D U C T S

AIRFLEX

TubeDiffusers

T H E S T R O N G E S T M E M B R A N E S

E C O N O M I C A L T O I N S T A L L

Airflex Tubes are available with Super SaddleTM or Nipple connections, in a variety oflengths and diameters. Our tubes are designed for maximal strength at a minimumpositive buoyancy. Although tubes are usually not as efficient as discs, tube diffusersare often the most economical choice of all diffusers, particularly the 3.7” diameter x39” Saddle Mount type (94mm x 1000mm) because of their relatively large size &high air capacity compared to disc diffusers. They require fewer header pipes, lesssupport stands, and less installation time than disc diffusers. If you are designing a finebubble aeration system on a tight budget, a tube aeration system may be for you.

Our Airflex Super Saddle mounts tightly on 4” Sch 40 PVC pipe or Sch 10 stainlesspipe with a 4.5” (114.3mm) or 110mm Outside Diameter. Threaded nipple typediffusers can be screwed into female sockets ordirectly into Sch 80 PVC pipe.

Tube membranes are extruded from low extractableoil content EPDM (though not as low as discmembranes) polyurethane, silicone or nitrile.Perforations are available in 1mm or 2mm slitlengths, and both saddles and nipples are designedto mount to US or Metric dimension pipes.

88" (2232mm)

39" (1000mm)

ø3.

7" (

94m

m)

24" to 39" (600 to 1000mm)

2.6

" (6

5mm

)or

3.7

" (9

4mm

)

3/4" NPT

Airflex Tube 1000 (AFT1000 with Super Saddle) 3.7” Ø (94mm) x length up to 39” per side (1000 mm) Design flow: 3 SCFM per foot of length (16 Nm3/hr per meter) Flow range: 0-9 SCFM per foot of length (0-50 Nm3/hr per meter) Slit Quantity: 45,200 per 39”/1000mm

Airflex Tube with SS Nipple 2.6” Ø (65mm) or 3.7” Ø (94mm) x length up to 39” (1000 mm) Design flow 2.6”: 2 SCFM per foot of length (11 Nm3/hr per meter),Range 0-5 SCFM/ft (0-28 Nm3.hr/m) Design flow 3.7”: 3 SCFM per foot of length (16 Nm3/hr per meter),Range 0-9 SCFM/ft (0-50 Nm3/hr/m) Slit quantity: 16,500 per 2.6” x 24”/65 x 610mm model

COMPARISON:

Discs& Tubes

Tube diffusers are idealfor retrievable systemsbecause they offer agreat deal of air capacityin a single unit. They arealso usually moreeconomical to installthan other types ofdiffusers even in fixedgrid systems becausethey require less piping,fewer stainless supportsand less labor to installthe system.

Our discs are the“premium” products,which offer efficiency,process and performanceadvantages, and arebetter at avoidingsettling of solids on thebasin floor. Discs aregenerally more expensivethan tubes, wheninstalled in a completesystem.

MATERIAL PROPERTY SPECIFICATIONS

PP DISC BASE & EPDM DISC EPDM TUBESPECIFICATIONS RETAINING RING MEMBRANE MEMBRANE

Coefficient of thermal expansion, in/in/deg. F x 10ˆ-5 (ASTM-969) 5 — —

Maximum operating temperature, deg. C 100 — —Tensile strength, psi @ 73F (ASTM D638) 5000 — —Tensile strength, psi (ASTM D412-92) — 2000 2000Tear strength, Die T, pli (ASTM D624-91) — 110 110Resistance to thermal deterioration, 70 hours @ 70°C,

(ASTM D573-88)a. Change of tensile strength, % — <3 <3b. Change of elongation, % — <25 <25c. Change of hardness, shore A reading — <5 <5

Ozone resistance, 70 hours, 40°C, 50mPa partial ozone pressure, non cracking (ASTM D1171-94) — pass pass

Extractable oil content — 10% 10%

*Dimensions and properties of other diffusers and accessories are available in our technical CD.

Discs& Tubes

P R O D U C T S

SSI disc diffusers are manufactured with flexibility in

mind. You can either connect diffusers to pipe using an

economical universal Grommet connector, or with a

proprietary Airflex Bayonet Quick Connect saddle. The

saddle is designed to mount onto 4”

Sch 40 PVC pipe or Sch 10 stainless pipe with a 114.3mm or

110mm Outside Diameter. Airflex Grommets are inserted into

a 1.25” straight hole drilled into PVC or Stainless pipe from

2.5” to 6” diameter (60mm to 150mm), Sch 40 or thinner

wall, and can be, but are not required to be solvent welded to PVC pipe. The

Bayonet mount allows a split second connection to pipe with a quarter turn,

reducing labor cost to install disc aeration systems. An integral seal is

provided in the saddle to ensure a leak-free connection. The Grommet

expands into the hole as threaded diffuser is

screwed in, sealing and tightening at the same

time. Both methods can resist a 200 pound pull-

out load while operating under 15 PSIG air

pressure without leakage.

Support stands are made of 304L or 316L stainless steel, and include clamps

with chamfered edges, threaded support rods or bent wire frame, washers,

nuts and anchor bolts or chemical anchors. SSI engineering will assist with

recommended rod diameter and anchoring options. Concrete ballasted

supports for soft membrane floors, pipe-in-pipe supports for high places such

as sloped digester floors, and weld-able supports for steel tanks are also

available. Both guide and fixed type stands are available & are used in our

complete system designs to avoid damage due to thermal expansion,

particularly in plastic piping systems.

AIRFLEXAccessories

Saddles and Grommets

Support Stands

Airflex Quick-Connect SaddleMount for Airflex Discs. Diffuserslock into place with a 1/4 turn.

Airflex UniversalGrommetsfor Disc Diffusers.Installs on Metric or USdimension pipe.

Our experience has shown us that thin wall PVC is not

easy to work with and doesn't necessarily make a good investment for a

township investing thousands of dollars in an aeration system, when

the savings compared to Schedule 40 pipe are quite minimal. Therefore

SSI recommends environmentally friendly Stainless Steel Sch 10, or as a

more economical option, PVC Schedule 40 pipes. Drop pipes are

typically Sch 10 304L SS to avoid UV degradation. Sch 80 PVC, as well

as CPVC, Polyurethane, and Galvanized piping systems are also

available. SSI fabricates piping systems in our Poughkeepsie factory, and

for international work, we allow approved distributors to produce SSI

factory approved piping systems themselves under our supervision.

Pipes are connected with stainless steel expansion joints, bolt

type expansion couplings, union connections or flanges,

depending on the requirements of the project.

SSI manufactures stainless steel

wide band and cap type coarse bubble

diffusers. Snap CapTM diffusers are also available. Complete

system design is available for all coarse bubble diffusers.

Pictured are positive displacement “RootsTM”, multistage centrifugal,

and side channel blowers. Single stage centrifugal blowers are also

available. Blowers are available bare shaft or packaged with motor and

accessories, and can be sized for 50 or 60 Hz. Please contact SSI for

data sheets on specific models or for general technical information

about different types of blowers.

Piping and Connectors

Coarse Bubble Diffusers

Blowers

All of the accessories

and components are

designed to work well

with each other and to

provide years of trouble

free service. Because we

are thoroughly familiar

with each component,

we can design our

systems for maximum

efficiency and

effectiveness.

GRIDS:

Retrievable& Fixed

SSIExperience

S Y S T E M S

SSI designs and manufactures both fixed grid and retrievable aeration type systems. Retrievable

systems are desirable when a plant has only a single aeration basin. They are also commonly used in

earthen lagoons with membrane liners. With a retrievable system installed, it is not necessary to decant

the tank in order to install or service the diffusers. Typically such systems are installed with flexible air

drop hoses, and can be designed with guide rails and winches for easy lift-out, or with eye bolts and

stainless cabling to enable crane liftout.

Fixed grid systems are the most common type of aeration system and

are usually more economical to install than retrievable designs.

All complete systems are supplied with complete engineering

drawings, submittals and O & M manuals. Startup and commissioning

services, and oxygen transfer testing services to ASCE or ATV standards

are available, as well.

Nine suppliers’ membrane diffuserswere evaluated. The 12” SSI Airflex™diffuser provided the performance wedesired plus the lowest, long-term, lifecycle ownership costs of any diffuserinvestigated. Approximately 2050 SSIdiffusers were installed in this BNR-capable facility. SSI has been a pleasure to workwith…their service was exemplary.

Cal Tininenko, Chief Scientist Bac Tee Systems, Inc.

SSI has supplied us with completefine bubble aeration systems, and weare most satisfied with the efficiency & performance of the product. We areequally pleased with the technicalsupport we receive during the designphase. We would highly recommendSSI.

William J. Lyon, Vice President Krofta Technologies Inc.

Since 1999, we have supplied andinstalled tens of thousands ofAIRFLEX fine bubble membranediffusers in Malaysia, both in domesticand industrial wastewater treatmentplants. We are happy with the highoxygen transfer from AIRFLEXdiffusers. Actual values in effluent isbetter than guarantee value.

Debbie Chee Tekno Suling, Malaysia

All these SBR plants are 6 to 8meters deep and we had nomechanical problems whatsoever withthe SSI fine bubble diffusers. Thesystem seems to have delivered theexpected performance as we had noproblems in meeting the treatmentperformance. We have also successfullyreplaced the SanitaireTM membranes ontwo projects in Quebec, Canada.

Gaetan Desjardins, PresidentEco Process & Equipment Int'l Inc. Montreal, Canada

Our SSI designed aeration systemworks very well, and continues to savemoney on energy costs. To this date wehave not needed to replace anymembranes, nor has there been anyother maintenance required on the SSIaeration system.

I would highly recommend SSI.

Scott L. Lods, President American Suburban Utilities, Inc.

We have sold Airflex diffusers toplant manufacturers and plant owners.(Complete) Systems were built withknow-how from SSI that supported usin the projects, calculations and choiceof materials. Results of applicationsare excellent. We have gotten savingsin energy costs up to 50% whencompared with previous diffusersystems.

Dr. Gianfranco Ramazzotti Tecneco Service S.a.s. Torino, Italy

CLIENT

Feedback

“”

“

”

“”

“

“”

“

”

AERATION DESIGNED FOR:

SBR,Traditional,

& NitrifyingSystems

”

Plant Name: West Lafayette WWTP Location: West Lafayette, Indiana USA Type: SBR Diffuser Qty: 3,000 pcs Airflex Disc (EPDM membrane)

Plant Name: Grand Forks WWTP Location: Grand Forks, North Dakota USA Type: BNR Plant Diffuser Qty: 2,050 pcs Airflex Disc (EPDM membrane)

Plant Name: Kwangju WWTPLocation: Kwangju, Korea Type: Traditional Activated Sludge Diffuser Qty: 28,700 pcs Airflex Disc (EPDM membrane)

Plant Name: Coca Cola Locations: Philippines, Vietnam and Malaysia Type: SBR & Traditional Activated Sludge Diffuser Qty: 7,300 pcs Airflex Disc (EPDM membrane)

Plant Name: Huntsville WWTP Location: Huntsville, Alabama Type: Traditional Activated Sludge Diffuser Qty: 13,000 pcs Tube Membrane (Polyurethane Membrane)

Plant Name: Nancun WWTP Location: Nancun, China Type: SBR Diffuser Qty: 1,440 pcs Airflex Tube 1000 (EPDM Membrane)

Plant Name: Brasilia WWTP Location: Brasilia, Brazil Type: BNR Oxidation Ditch Diffuser Qty: 6,600 pcs Airflex Disc (EPDM Membrane)

Plant Name: Acqui Terme WWTPLocation: Torino, ItalyType: Traditional Activated Sludge Diffuser Qty: 2,000 pcs Airflex Disc (EPDM Membrane)

SSI has installations of tube and disc diffusers in North and South America, Europe,Asia, the Middle East and Africa. Consulting engineers such as CH2M HillTM andEarth TechTM have used our systems. Fortune 500 companies such as Coca-ColaTM,Pepsi-ColaTM, NestleTM, KraftTM, Conoco/Philips PetroleumTM, Sonoco, ReynoldsAluminum, are also among SSI‘s customers. A few sample installations include:

TM

S T A M F O R D S C I E N T I F I C I N T E R N A T I O N A L I N C .

4 Tucker Drive

Poughkeepsie, NY 12603

USA

845-454-8171

fax: 845-454-8094

www.StamfordScientific.com

email: info@stamfordscientific.com

SSI aeration products and systems are

warranted to be free from defects in

manufacture or workmanship for 12

months from the date of installation, up to

18 months after the date of shipment.

Parts found to be defective in materials or

workmanship will be repaired or replaced

without charge, with freight to be at our

option. The responsibility of SSI is limited

to the cost of defective parts. Damage

caused to SSI aeration products by

chemicals, wear caused by the presence of

abrasive, sticky or oily materials, poor

maintenance, installation or operation not

in accordance with our manual shall not

constitute defects. SSI is able to stand

behind our pledge of quality because we

continually test all our equipment ensuring

greater quality control. All of our test results

are made available upon request.

SSI manufactures replacement membranes for most other manufacturers‘

diffusers. We can also assist with fouling problems experienced with other

vendors' products, including specially formulated membrane compounds to

resist calcium buildup and recommended membrane cleaning methods.

Tube membranes are available in Nitrile and

Silicone materials as well as EPDM and

Polyurethane, in a variety of lengths and

diameters. We can supply tube membrane

replacement sleeves to replace most

manufacturer‘s products. Tube membranes have

2mm wall thickness, and are available with 1mm or 2mm

perforations. Economical stainless steel replacement clamps

and hand or pneumatic crimping tools to fasten ear-type

clamps to the diffuser are also available.

Disc membranes are interchangeable with

SanitaireTM. We make support plates to enable

conversion of SanitaireTM and other ceramic

diffusers to our membranes. Replacement disc membranes are also

available for most major diffuser manufacturers in 7”, 9” and 12” sizes, in

EPDM, Silicone, and Nitrile materials.

Distribution and Service Centers WorldwideCall for an agent near you.

SSIWarranty

Replacements& Retrofits

56mm 60mm62mm 65mm 69mm 75mm 91mm 92mm

7”

9”

12”

AVAILABLESizesTUBE DISC

Insi

de D

iam

eter

s.

We are not affiliated with Sanitaire or any other product or company mentioned in thisbrochure. All trademarks, patents, etc., are the property of their respective owners.