WELDED DUCTS

http://qadnet.com

WELDED DUCTS

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WELDED DUCTS

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INTRODUCTIONWelded QAD-DUCTS are fabricated from another predominant line of production. It is mainly Classified with dedicated application process as follows,

1. Welded Black Steel Ducting,2. Welded MS Ducting,3. Welded SS Ducting,4. Welded Aluminium Ducting.

1. 1. Black steel & Mild Steel Ducting are manufactured from Hot / Cold Rolled Coils a minimum of 16 gauge (1.6 + / - 1.0 mm) thick metal, which complies with NFPA 96 / QCS.

2. 2. QAD-DUCT Welded Stainless Steel Ducts (SS Ducts) are made from Grade 304 / 316 2B Finish, a minimum of 20 gauge (1.0 mm) thick metal, which complies with NFPA 96.

3. 3. Welded Aluminium Ducts are fabricated as per customer specification.

Both Welded Black Carbon Steel Ducts & Stainless Steel Ducts are mainly for Grease Duct Extract system and vent grease vapors from cooking equipment to outside the building boundary for safety purpose. At production area we give special importance in fabricating those types of duct works, knowing the safety requirements and hazards in venting those types of fumes.

This type of duct is mainly used for the Kitchen

Ventilation System; it will be fixed to the exhaust fans that takes the air/ odor to outside of the kitchens/cooking areas.

In Restaurants kitchens, the temperature usually goes over 100°C, beside the high humidity levels, which occurs an uncomfortable environment in the Restaurants / Hotels.

When the Ventilation System is well designed, it will be more than just an exhaust hood; It will also involve the complex interface of the kitchen with the other spaces of the restaurant.

Hence, this kind of Ventilation System represents and assure the Ideal Design condition for Commercial Cooking Systems in Restaurants and Hotels.

All welded type QAD-DUCTS are manufactured through latest welding technology through American and European welding machines and Our experienced welding teams are certified and qualified for any kind of welding requirements.

All kind of Welding activities are followed with predefined welding procedure (WPS) / methodology certified by 3rd Party.

Welders are qualified by one of the approved certification body and it is based on appropriate WPS (Welding Procedures Specifications) and it is being audited periodically and renewed by them.

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WELDED DUCTS

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FABRICATION PROCEDURESFabrication of Welded Rectangular / Circular Ducts shall be based on Approved Drawings/Worksheets provided by the client. Production shall follow below Fabrication Procedures to meet the client’s requirement;

Receipt of Approved Shop drawing / worksheets from Clients.

The Shop Drawings / Worksheets shall be reviewed through latest Autodesk CAD-MEP software and identified type of ducting required to client and as per commercial order confirmation.

Drawings are tagged and identified with proper annotation of Fan / Equipment / service references.

In Parallel, Every Individual duct parts / fittings are nested through Latest Autodesk CAM-DUCT Software to Estimate the Drawing Quantity & Bill of Material required for fabrication.

4KED-1

TAKE OFF SHEETITEM LIST / PACKING LIST

Tag Ref.

Fitting Description

Gauge Thickness

(mm)

"End 1 (W1 x D1)

mm"

"End 2 (W2 x D2)

mm"

Length (mm) /Angle (Deg) Qty Connector #1 Connector #2

K1 Radius Bend 1.5 750x1800 750x1800 90 1 RSA 40 X 40 RSA 40 X 40K2 Straight 1.5 1800x750 1800x750 511 1 RSA 40 X 40 RSA 40 X 40K3 Straight 1.5 1800x750 1800x750 1220 1 RSA 40 X 40 RSA 40 X 40K4 Straight 1.5 1800x750 1800x750 1006 1 RSA 40 X 40 RSA 40 X 40K5 Taper 1.5 1800x750 1800x750 650 1 RSA 40 X 40 RSA 40 X 40K6 Straight 1.5 1450x750 1450x750 1220 1 RSA 40 X 40 RSA 40 X 40K7 Straight 1.5 1450x750 1450x750 1208 1 RSA 40 X 40 RSA 40 X 40K8 Straight 1.5 1450x750 1450x750 1208 1 RSA 40 X 40 RSA 40 X 40K9 Straight 1.5 1450x750 1450x750 1208 1 RSA 40 X 40 RSA 40 X 40K10 Straight 1.5 1450x750 1450x750 1208 1 RSA 40 X 40 RSA 40 X 40

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WELDED DUCTS

FABRICATION PROCEDURES

Raw materials (Sheets) are used conservatively on Machines and % of scrap generation are worked out in advance through CAM-DUCT software. This will help to have control on % of material scrap.

An accurate BOQ shall be issued including connectors (Type of Flanges).

Forward the Completed Tagged drawing, Take off and BOM for Client confirmation.

Upon 100% confirmation from Client’s Our Engineering team will review and forward to further pre-production process.

The Fabrication Data shall be saved as program and shall be printed out into different Job Orders and Fabrication sheet issued for both Standard Length Straight Duct production & Fittings.

The Job orders shall be forwarded to the Plasma and Automated Duct Line machines for cutting and items identification, as follows:

For Straight Rectangular ducts, ducts are produced from standard cut sheets of 1220 x 2440 and shall be cut into sheets and folded through Mechanical Shear & Folding machine. This can be proceeding through automated coil line machine, In case of lesser in thickness (<1.2mm) for Mild steel / Black steel / Aluminum.

For All other nonstandard length straight & Nonlinear Fittings (Elbow, Tee, Reducer, etc..), the sheets shall be cut through the Plasma Cutting Machine into individual marked pieces; then shall be taken to the Welding area.

All parts (Straight & Fittings) are then folded as per the requirements and assembled by welding using TIG/ ARC / MIG Welding Machine as per thickness and type of welding requirements.

Transverse Joint Connectors shall be fixed to the ducts/fittings with pre-fabricated welded frame with or without holes for bolting. (Sizes, Grades are followed as per project specification); stiffener shall be applied in the outer middle of the duct if required.

All Connectors/Joints that shall be fixed to the Ducts and Fittings, shall comply with the project specification and it shall be suitable for bolted / welded as per client convenient and approved project standards.

After Welding process finishes, deburring, grinding and buffing process shall be carried out for material readiness.

After the above procedures, all fabricated ducts shall be carried forward to painting / Coating as per the project / standard requirements.

Upon completion of fabrication, all items shall be holding QAD-NET label with following Basic information’s and it can be scanned through bar code scanner.

1. Project Name,2. Tag No.,3. Job Reference.4. Date,5. Customer Name6. Type of Materials (GI, SS, BS, Alum. etc)7. Weight, Length, Area,8. Insulation Thickness & Density (if any) 9. Connector Dimension10. Item Type (Straight, Elbow, Tee Reducer, etc.)

QA QC shall be conducted before each delivery in order to indicate the QC “Passed” or “Rejected” Stamp.

Quantity of items ready for delivery shall be bar coded generated by ERP software, same as mentioned in the Delivery documents.

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WELDED DUCTS

STRAIGHT & FITTINGS

STRAIGHTStandard Length 1220mm

RADIUS BEND

DROP CHEEK BEND

TAPER / REDUCER

MASTER BEND

TROUSERS PIECE

1

3

5

2

4

6

Minimum Throat Radius (R) = 100mmQAD-DUCT Standard Throat Radius (R) = 150mm

Minimum Throat Radius (R) = 150mm

Minimum Throat Radius (R) = 150mm

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ANGLED OFFSET

RADIUS 2-WAY OFFSET

SQUARE TEE

STRAIGHT + 2 BRANCHES

STRAIGHT + BRANCH

4

7

9

11

8

10

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WELDED DUCTS

STRAIGHT & FITTINGS

DOWN/UP

DOWN/UP

RADIUS OFFSET

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WELDED DUCTS

FITTINGS

BREECHES PIECE

SIDE BRANCH

DROP CHEEK BREECHES PIECE

3-WAY TEE

Y PIECES

ACCESS DOOR

*Contact sales team for any customized design / construction requirements.

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16

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WELDED DUCTS

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WELDED DUCT WORKS CONSTRUCTION DETAIL (TYPICAL).STRAIGHT DUCTS WITH FLANGE STEEL ANGLES

FLANGED CROSS JOINT

TYPICAL LAYOUT - BILL OF MATERIALANGLE FLANGED JOINT

FLANGE STEEL ANGLEFixing Bolts at Each Corner and intermediately Centered at 150mm

Continuous Welded

Duct

Gasket or Sealant

Semi-continuousWelding

Fixing BoltsDimensions Bolts Diam.25x25x3mm 8mm30x30x4mm 8mm40x40x4mm 8mm50x50x5mm 10mm60x60x6mm 12mm

PARTS LISTDESCRIPTIONPART NUMBERQTYITEM

As Per Tag SheetDuct W X H X L21As Per BS 23RSA Angle Assembly42ARBO SealFire Rated Gasket13

Access door Assly 300X300 MM14M8 Bolt Nut Set145

APPROVEDDRAWN

DATE

SHEET OF REV

Typical Construction For Size 1201-3000 mm

FLAMESHIELD KED DUCTWORKS

Note :1. Bare Duct Sheet Metal Thickness shall be 1.4mm as per Flameshield Fire rated KED Duct work Standards.

2. All Untreated Steel including Spot Welding are to be painted with Gray- Zinc Phosphate Primer Both Inside & Outside.

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AMEER MUSTHAFA

KUMAR

28/07/2020

KED

TYPICAL WELDED DUCT WORK CONSTRUCTION- BOM

ITEM QTY PART NUMBER DESCRIPTION

1 2 Duct W X H X L As per worksheet / tag sheet

2 4 RSA welded frame assembly As per approved construction table.

3 1 Fire Rated Gasket As per approved Gasket material

4 1 Access door Assly typical as per client requirement (300X300 MM)

5 14 M8 Bolt Nut Set Minimum size

Note:All Untreated Steel including Spot Welding are to be painted with appropriate primer (or)Grey- Zinc Phosphate Primer Both Inside & Outside.

Tack Weld

PARTS LISTDESCRIPTIONPART NUMBERQTYITEM

As Per Tag SheetDuct W X H X L21As Per BS 23RSA Angle Assembly42ARBO SealFire Rated Gasket13

Access door Assly 300 X300mm

14

M8 Bolt Nut Set145APPROVEDDRAWN

DATE

SHEET OF REV

Typical Construction For Size 0-1200 mm

FLAMESHIELD KED DUCTWORKS

1 1

28/07/2020

KUMAR

AMEER MUSTHAFA

KED

ACCESS DOOR WITH INSULATION

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WELDED DUCTS

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A A

300,

0030

,00

86,0

0

1,50

130,

0013

0,00

50,0

0

50,00

6

3

1

5

2

KED ACCESS DOOR (TYPICAL) CONSTRUCTION- BOM

ITEM QTY PART NUMBER DESCRIPTION

1 1 Frame Assembly Same as Duct Material

2 1 Gasket Approved Gasket

3 12 M6 Stud Steel

4 1 Door Assembly Insulated door assembly (Use approved insulation)

5 12 Wing Nut Steel

6 12 Washer Steel

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ACCESS DOOR ASSEMBLY WITHOUT INSULATION

TABLE 1

C

D

A

B

1

W

H

2 3

54

6

7

CERAMICGASKET

ACCESS DOOR ASSEMBLY 1.5 mm B.Steel AS PER NFPA 96-2011

CHAPTER : 7.4.3 ACESS PANEL (7.4.3.1 to 7.4.3.4)

MATERIAL DESCRIPTION ITEM DESCRIPTION SIZE REMARK 1 STUD 8mm @250mm2 GASKET 12mm CERAMIC TYPE 3 WING NUT 15mm STEEL 4 DOOR W x H One Guage higher than duct material5 M10 HOLE 10mm @250mm6 HANDLE 1.20mm Two Guage higher than duct material7 DUCT FLANGE RSA B. STEEL

CONFIGURATIONWxH DUCT SIZE

AxB ACCESS DOOR OPENING

CxD OUTER FRAME SIZE

C A+100

D B+100

DUCT CONSTRUCTION TABLE FOR BS / MILD STEELKED TABLE -1 FOR BEARRIER SPACE @ 1.5 MTR DISTANCE

Sl. No.

Duct Size (Longest

side) in mm

Thickness (mm)

Maximum Standard

Length duct (mm)

Re-inforcement spacing

(Jointing)

Transverse Joint (Fully welded type)

Intermediate re-inforcement sizes

1 0 to 600 1.5 1220 1220“Welded RSA flange 25 x 25 x 2.5

RSA fully welded *RSA 30 X 30 is Optional”

NR

2 601 to 1200 1.5 1220 1220 Welded RSA flange 30 x 30 x 3.0 RSA fully welded NR

3 1201 to 2000 1.5 1220 610 Welded RSA flange 40 x 40 x 4.0 RSA fully welded

RSA 40 x 40 x 4mm tack welded @ 300 mm Centres.

4 2001 to 3000 1.5 1220 610 Welded RSA flange 50 x 50 x 5.0 RSA fully welded

RSA 50 x 50 x 5mm tack welded@ 300 mm centres.

Note:-1 “Above construction table is as per “”Manufacturer

recommendation”” based on Material Weight, Reinforcement requirements. Since, it is followed for KED application - above table has abstracted from NFPA-96 & DW172 for Kitchen Ventilation System norms.

2 Duct Gauge Thickness follows as per Project specification.3 Cross Joint Fixing - Fully Welded4 Stiffeners can be either 40 x 40 x 4 RSA or 50 x 50 x 5 RSA, refer to

table for tack welded @300 mm Centres. Corners to be cropped.5 All Stiffeners must be “Back to back”.6 Longitudinal Joints & Sheet joints to be fully welded

7 Regarding radius bends,half width throat radius will not have any splitter vanes.

8 For Square bends, if the width of the duct is > 450 mm size, similler gauge thickness shall be followed for air turning vanes and tuck / spot welded with Duct works.

9 All Un-treated steel including spot welds are to be treated with painted with a gray Zinc Phosphate primer inside and outside @ factory.

10 All Un-treated cross joints / Welded joints for Duct -Duct shall be treated with project approved anti corrosive paints (Contractor’s scope)

11 Access panel to be fixed at every 12’ & every directional changes on air flow path, as per NFPA -96 ; 7.4.3 ACCESS PANEL.

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TABLE 2

DUCT CONSTRUCTION TABLE FOR STAINLESS STEEL DUCT WORKS FOR DISHWASHER EXHAUST

Sl. No.

Duct Size (Longest

side) in mm

"Thickness (Min - Max)

in mm"

Maximum Standard

Length duct (mm)


(Jointing)

Transverse Joint (Fully welded type) Intermediate re-inforcement sizes

1 0 to 600 1.0 - 2.0 12201220

Welded RSA flange 25 x 25 x 2.5 RSA fully welded (30 X 30 X3 RSA -

OPTIONAL)NR

2 601 to 1200 1.0 - 2.1 1220 Welded RSA flange 30 x 30 x 3.0 RSA fully welded NR

3 1201 to 1600 1.0 - 2.2 1220

610 (1.0 - 1.2 mm)

1220 (1.4 - 2.0 mm)

Welded RSA flange 30 x 30 x 3.0 RSA fully welded. (optional - M8 NUT

Bolts @ 300 MM Centre)

*RSA 30 x 30 x 3mm tack welded @ 300 mm Centres.

4 1601 - 2000 1.0 - 2.3 1220Welded RSA flange 40 x 40 x 4 RSA fully welded. (optional - M8 NUT

Bolts @ 300 MM Centre)

*RSA 40 x40 x 4 mm tack welded @ 300 mm Centres.

5 2001 to 3000 1.0 - 2.4 1220Welded RSA flange 50 x 50 x 5.0 RSA

fully welded. (optional - M8 NUT Bolts @ 300 MM Centre) with JTR

*RSA 50 x 50 x 5mm tack welded@ 300 mm centres.

Note:-1 Above construction table is as per “Manufacturer

recommendation” based on Material Weight, Reinforcement requirements.

2 Duct Gauge Thickness shall follows as per Project requirement . 3 Cross Joint Fixing - Fully Welded / Bolted with Gasket - Subjected

to Client confirmation. 4 Intermediate re-inforcement specified here in this chapter is

“Manufacturer recommendation only” . All Stiffeners must be “Back to back”.

5 Longitudinal Joints & Sheet joints to be fully welded 6 Regarding radius bends,half width throat radius will not have any

splitter vanes. 7 For Square bends, if the width of the duct is > 450 mm size, similler

gauge thickness shall be followed for air turning vanes and tuck / spot welded with Duct works.

8 Tie-rods is recommended for >2000mm sizes. 9 In the event of the depth of the duct being in excess of 2000mm a

tie-rod needs to be fitted horizontally from side to side and tack welded where they cross.

TABLE 3

DUCT CONSTRUCTION TABLE FOR ALUMINIUM DUCT WORKS FOR POOL, SPA & LAUNDRY APPLICATION

Sl. No.

Duct Size (Longest side) in

mm

Thickness (mm)

Maximum Standard

Length duct (mm)


(Jointing)

Longitudinal seam joints

Transverse Joint (Fully welded type)

Intermediate re-inforcement sizes

1 0-300 1.2 1220 1220 Pittsburg Lock S&C Nil.

2 351 - 900 1.2 1220 1220 Pittsburg Lock

"Companion Angle 30 x 30 x 3mm" Nil.

3 901 - 1200 1.2 1220 610 Pittsburg Lock

"Companion Angle 30 x 30 x 3mm Fixed

with Rivet / Mechanical punching."

30 x 30 x 3 mm; Tag welded / Rivete @300 min distance.

4 1201 - 1800 1.5 1220 610 Welded Joint"Companion Angle

40 x 40 x 4mm, Fixed with Rivet/Mechanical Punching"


4 1801 - 2400 1.5 1220 610 Welded Joint"Companion Angle

50 x 50 x 5mm; Fixed with Rivet/Mechanical Punching"


5 2401 - 3000 2 1220 610 Welded Joint"Companion Angle

50 x 50 x 5mm; Fixed with Rivet/Mechanical Punching"


Note:-1 Above construction table is as per “SMACNA HVAC Duct

construction table - 2005” 2 Duct Gauge Thickness follows as per Project requirement & as per

SMACNA - Whichever specify as higher. 3 Cross Joint Fixing - Fully Welded / Bolted with Gasket - Subjected

to Client confirmation.

4 All Stiffeners must be “Back to back”. 5 Radius bends as DW144 half width throat radius, no splitters. 6 Square bends as DW144. Standard gauge air turn trackis riveted or

spot welded to the ducts @150mm centres. 7 Consult Qad-Duct sales for additional tie rod requirements for the

sizes >1800 mm.

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WELDED DUCTS

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TABLE 4

HANGERS & SUPPORT TABLE FOR BS / MILD STEEL / SS ‐ KITCHEN EXHAUST DEUCT WORKS (HORIZONTAL DUCTING)

TABLE - 4A, FOR BEARRIER SPACE @ 1.5MTR DISTANCE

Sl. No.

Duct Size(Longest side) in

mm

Thickness(mm)

Support Size Rod Size

L ‐ ANGLE STRUT CHANNEL (Alternative) mm

1 0‐350 1.5 25 x 25 RSA 40 x 20 x 2.5 RSC M8

2 351 - 700 1.5 30 x 30 x 3 RSA 40 x 20 x 2.5 RSC M8

3 701 - 1200 1.5 40 x 40 x 4 RSA 40 x 40 x 2.5 RSC M8

4 1201 - 1600 1.5 40 x 40 x 4 RSA 40 x 40 x 2.5 RSC M10

5 1601 - 2100 1.5 50 x 50 x 5 RSA 40 x 60 x 2.5 RSC M10

6 2101 - 3000 1.5 50 x 50 x 5 RSA 40 x 60 x 2.5 RSC M12

TABLE ‐ 4B, FOR BEARRIER SPACE @ 2.2 MTR DISTANCE

Sl. No.

Duct Size(Longest side) in

mm

Thickness(mm)



1 0‐250 1.5 25 X 25 RSA 40 X 20 X 2.5 RSC M8

2 251‐450 1.5 30 X 30 X 3 RSA 40 X 20 X 2.5 RSC M8

3 451 - 1100 1.5 40 X 40 X 4 RSA 40 X 40 X 2.5 RSC M8

4 1101 - 1200 1.5 50 X 50 X 5 RSA 40 X 60 X 2.5 RSC M8

5 1201 - 1600 1.5 50 X 50 X 5 RSA 40 X 60 X 2.5 RSC M10

6 1601 - 2100 1.5 50 X 50 X 5 RSA 40 X 60 X 2.5 RSC M10

7 2101 - 2750 1.5 50 X 50 X 5 RSA 40 X 60 X 2.5 RSC M12

8 2751 - 3000 1.5 50 X 50 X 5 RSA 76 X 38 RSC M14

TABLE ‐ 4C, FOR BEARRIER SPACE @ 3.0 MTR DISTANCE

Sl. No.Duct Size

(Longest side) inmm

Thickness(mm)



1 0‐150 1.5 25 X 25RSA 40 X 20 X 2.5RSC M8

2 151 - 300 1.5 30 X 30 X 3RSA 40 X 20 X 2.5RSC M10

3 301 - 800 1.5 40 X 40 X 4RSA 40 X 40 X 2.5RSC M10

4 801‐1200 1.5 50 X 50 X 5RSA 40 X 60 X 2.5RSC M10

5 1201 - 1600 1.5 50 X 50 X 5RSA 40 X 60 X 2.5RSC M10

6 1601 - 2000 1.5 50 X 50 X 5RSA 40 X 60 X 2.5RSC M12

7 2001 - 2100 1.5 76 X 38RSC 76 X 38RSC M14

8 2101 - 3000 1.5 76 X 38RSC 76 X 38 RSC M16

• Transvers Joints, Reinforcements details shall be followed as per Approved Duct Construction Table• Support table abstracted from SMACNA HVAC duct construction standard ‐ 2005 Third Edition.• Reference Table: ‐ Table 5‐1M ; 5‐3M; 5‐4• Reference Figure:‐ FIGURE 5‐5 Hangers and supports.

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SUPPORT BEARER CONFIGURATION

Typical Configuration of Slotted Channel

Typical configuration of Back to Back Slotted Channel

NOTES

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