Innovations in Mechanized Cutting - Tank · -All bevels in a single cut pass-Chamfering (1:4TYP)-Bevel prep is consistent and accurate (+/-2mm) - Part size and square affected by

10/2/2009

Innovations in Mechanized Cutting

Mechanized Cutting ReviewThe Process of Selecting Process

Overview of plasma, oxyfuel, laser and waterjetQuality / Speed / Cost

• To be(vel) or not to be(vel)• Criteria for acceptable bevel results

• Figuring out Configurations• When automation makes sense• Options for increased productivity and accuracy in large plate cutting

• Collecting Data• Machines that talk back (figuratively speaking)• Cleaning up around the edges – how to make seconds save thousands

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Basis for Process Comparison50

Hp

Abra

sive

W

ater

jet

Oxy

fuel

Lase

r

300

Amp

Plas

ma

Description50Hp Pump (30Hp is less expensive but

slower cutting)

Propylene as fuel gas (Natural gas is less

expensive but slower cutting)

3000 and 4000 Watt (6000 Watt

offers higher speed at higher cost)

300 Amp Cutting. 400 amp is faster

but more expensive and not appropriate

for thinner plate.

Production Labor

Assignment

1 Person. Operation and clean and clear

table.

2 People. 1 for operation and 1 to

clean and clear table and parts

1 Person. Operation and clean

and clear table.

1.5 People. Both for operation and to

clean and clear table and parts.

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0

100

200

300

400

500

600

700

Cut

Fee

t

1/8 1/4 3/8 1/2 3/4Thickness (Inches)

Cut Feet per Hour

OxyFuelPlasma (300A)Waterjet

Laser (3000)Laser (4000)

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$0.00$50.00

$100.00$150.00$200.00$250.00$300.00$350.00


Cost per 100 Feet

OxyFuelPlasma (300A)WaterjetLaser (3000)Laser (4000)

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$0.00$5.00

$10.00$15.00$20.00$25.00


Cost per 100 Feet (Plasma and Laser Only)

Plasma (300A)Laser (3000)Laser (4000)

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Innovations in Mechanized Cutting Aggregate Costs

($120.00)

($100.00)

($80.00)

($60.00)

($40.00)

($20.00)

$0.00

Oxy

Fuel

Plas

ma

(300

A)

Wat

erje

t

Lase

r(3

000)

Lase

r(4

000)

Process

Cos

t ($

per h

our)

Interest Rate

Depreciation

Gasses, W ater orAbrasives

Power

Maintenance/Repair

Labor

Consumables

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To Bevel or not to Bevel

Defining Bevels

Oxyfuel Plasma

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-All bevels in a single cut pass

-Chamfering (1:4TYP)

-Bevel prep is consistent and accurate (+/-2mm)

- Part size and square affected by thermal distortion of plate while cutting

-Y, X & K bevel requires multiple pass cutting

-Maximum 50°

-Bevel prep consistency challenged by plate movement between passes and arc voltage / consumable wear

- Part size consistent and accurate (+/-1.5mm)

Oxyfuel Plasma

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- Cut long sides simultaneously

-Cut underwater (plasma)

- Use tactile sensing when possible

Maximizing Part and Edge Prep Accuracy

h

h

h

h

h

h

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To Bevel or not to Bevel

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Representative Results

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Thermal verses Mechanical Bevel9’x30’ Shell

K36.813.423.440.2701.0"

Y18.46.711.713.41401/2"

Bevel Type

Total Plasma and Mechanical

Plasma Only Time

Mechanical Beveling

Time

Part Cutting

Time

Plasma Cutting Speed

Carbon Steel Thickness

As a result of distortions that occur when cutting with thermal processes, a mix of thermal cutting and mechanical beveling may be the most advantageous.Best used when…- Part size is large with few sides, like tank or tower shells- Thickness is under 1.25”(32mm)

Relative Cost Comparison: Contour Plasma Bevel Station $100,000Portable Mechanical Bevel Machine $ 30,000

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Configuring Cutting

When does automation of the cutting process make sense?

It shouldn’t be this confusing…

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Getting to Return on AssetLet’s review the Aggregate Cutting Costs again…

Aggregate Costs

($120.00)

($100.00)

($80.00)

($60.00)

($40.00)

($20.00)

$0.00

Oxy

Fuel

Plas

ma

(300

A)

Wat

erje

t

Lase

r(3

000)

Lase

r(4

000)

Process

Cos

t ($

per h

our)

Interest Rate

Depreciation

Gasses, Water orAbrasives

Power

Maintenance/Repair

Labor

Consumables

Oxyfuel - LaborPlasma - Labor, Consumables

10/2/2009


Getting to Return on AssetLet’s review the Aggregate Cutting Costs again…

Aggregate Costs

($120.00)

($100.00)

($80.00)

($60.00)

($40.00)

($20.00)

$0.00

Oxy

Fuel

Plas

ma

(300

A)

Wat

erje

t

Lase

r(3

000)

Lase

r(4

000)

Process

Cos

t ($

per h

our)

Interest Rate

Depreciation

Gasses, Water orAbrasives

Power

Maintenance/Repair

Labor

Consumables

Oxyfuel - LaborPlasma - Labor, Consumables

Oxyfuel Automation- Automatic Height Control – up to 40% labor reduction- Automatic Station Spacing- Automatic Gas Control

Plasma Automation- Single Pass Bevel- Speed Loaders for Torches- Automatic Gas Control- Using the right consumable for the right thickness

For plasma, cutting at 400 amps on all thicknesses will nearly double the consumable cost shown here.Cutting at the right current for the right thickness can reduce consumable cost by up to 50%. This will impact cut feet per hour.

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Getting to Return on Asset

Dedicated Purpose verses Combination Machines

-When combining oxyfuel, plasma, waterjet or drilling on a single gantry machine, consideration should be given to the cost of the assets that are idle while other assets are utilized.

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Dedicated Purpose verses Combination Machines

-Running dedicated process machines over common cutting tables can…- Reduce floor space- Increase capacity utilization- Decrease overall capex- Potential for reduced labor and cutting hour requirements

Specialty cutting area by both machines (heads, pipe, etc)

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While the initial capex is higher, the cutting processes more quickly achieve >60% utilization and the return on these assets is faster.

Adding Dual Asynchronous Drives with dual stations improves throughput by as much as 40%.

Specialty cutting area by both machines (heads, pipe, etc)

h

h

h

h

h

h

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Getting to Return on Asset – Marking Systems

Punch Plasma (Cut/Mark)

Pin Stamp Inkjet

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Punch

Plasma (Cut/Mark)

Pin Stamp

Inkjet

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Punch

Plasma (Cut/Mark)

Pin Stamp

Inkjet

Plasma Marking…..100-400ipmPunch Marking…….100-200ipmInkjet………………..5cps/500ipmPinStamp…………..4cps/400ipm

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Measuring Results – Machines that Talk Back

Running continuously in the background, new cutting machines have the ability to automatically collect and report operating data in real time.

1. Process ‘on’ time by each process2. Machine idle time (and reasons for

idle)3. Consumable use4. Gas consumption in real time5. Electricity consumption6. Maintenance time

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Measuring Results – Machines that Talk Back

With this data, you can determine…

1. What are the true obstacles to higher productivity

2. What are the primary causes for down time

3. What operators / shifts are most efficient

4. What is the actual vice predicted processing time

This provides valuable information for…1. Better capex decisions2. Better costing data3. Faster repair time / lower down time

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Special Cutting Challenges – Stainless Steel ApplicationsEverything old is new again – The brief history of plasma

Plasma – Tungsten electrode with nitrogen gasOxygen Plasma – Hafnium electrode with oxygen cut gasWater Injection Plasma – Nitrogen or oxygen surrounded by deionized water to

improve edge bevelPrecision Plasma – Remove the deionized water and replace with shielding gas of

air, oxygen, nitrogen or a mix

Unfortunately, this created oxide issues with stainless steel.

Precision Plasma – Add H35, Methane or other tri-mix gasses to improve stainless steel cutting

Good for plasma manufacturers, bad for people cutting stainless steel as cutting costs increase

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Special Cutting Challenges – Stainless Steel ApplicationsEverything old is new again

Plasma – Tungsten electrode with nitrogen gasOxygen Plasma – Hafnium electrode with oxygen cut gasWater Injection Plasma – Nitrogen or oxygen surrounded by deionized water to

improve edge bevelPrecision Plasma – Remove the deionized water and replace with shielding gas of

air, oxygen, nitrogen or a mixPrecision Plasma – Add H35, Methane or other tri-mix gasses to improve stainless

steel cutting

Water Injection Plasma / Gas Sheilded Plasma from the same systemCut with water injection on stainless steel, change the speed load

torch to Gas Shield plasma for carbon steel.

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Special Cutting Challenges – Stainless Steel ApplicationsEverything old is new again

Water Injection Plasma / Gas Sheilded Plasma from the same system

Cut with water injection on stainless steel, change the speed load torch to Gas Shield plasma for carbon steel.

Water injection cutting on stainless steel produces a more weldable edge, virtually no grinding, and lower cost plasma operation.

10/2/2009


Cutting Tables

Documents

Innovations in Mechanized Cutting - Tank · -All bevels in a single cut pass-Chamfering (1:4TYP)-Bevel prep is consistent and accurate (+/-2mm) - Part size and square affected by