Corrosion Products Sampler (CPS)

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Corrosion Products Sampler (CPS)
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New CPS Features

• New flow meter totalizer
• AC connection standard
• 90-264Vac 47-63Hz input
• Battery option available
• Battery indication meter
• Average 3 month runtime between charges
• 24-48 hr recharge time
• Total volume is customer resettable
• Flow rate can also be displayed (mL/min)

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Corrosion Products Sampler (CPS)

• Collects a sample of dissolved and particulate
  materials
• Totalizes sample flow
• ASTM D6301-98
• Corrosion studies and pseudo on-line corrosion
  analysis
• Boiler tubes, pre-heaters, condenser

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CPS Flow Diagram
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CPS Benefits

• Identify corrosion products
• Collects particulates for metals analysis - Fe,
  Cu
• Use anion and cation filters for dissolved metals
• Locate source of corrosion
• Quantify rate of corrosion
• Measure effectiveness of treatment
• Locate areas of corrosion product accumulation

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Major Components

• High pressure filter holder
• Totalizing meter for high accuracy/low flow rates
• Flow control circuit
• Optional bypass circuit
• Optional sample cooler (Above 55C)
• Optional battery pack

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Sample Point Selection

• Based on
• System design
• Subject constituents
• Chemical treatment
• System specific problems

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Corrosion

• Corrosion affects
• Equipment reliability
• Plant safety
• Efficiency and capacity

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Corrosion

• Specifically
• Material degeneration at point of attack
• Migration through the system
• Collection on turbine blades
• Collection on heat transfer surfaces
• Accumulation at various points leading to
  additional corrosion

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Why Sample?

• Improve plant safety equipment reliability
• Increase plant efficiency and capacity
• Reduce frequency between routine cleanings of
  plant heat exchanger equipment
• Reduce plant operating costs

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Why Sample?

• Use sample data to
• Make adjustments in treatment
• Make adjustments in lay up procedures
• Schedule maintenance

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Why Sample?

• Locate the sources of corrosion products
• Economizer, Condenser, etc.
• Determine the rate of corrosion
• Historical base, startup deviations, treatment
  changes
• Identify the type and cause of the corrosion
• Type of material
• Track the path of corrosion products
• Collection, settling, material removal

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Typical Sampling Points

• Hotwell
• Monitor starting concentrations.
• DA Outlet
• Monitor quality of feedwater indicating problems
  with feedwater system components.
• Economizer Inlet
• Quality of feedwater entering the boiler
• Steam
• Quality of steam to turbine

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Proper Corrosion Products Sampling Technique

• Isokinetic Sampling
• Sample velocity entering sample port is same as
  sample stream
• Sample Flow rate
• Constant, continuous
• New lines should be seasoned
• Location
• As close as possible to the source
• Fittings/Bends
• Minimize
• Tube Diameters
• Select to provide 6 ft/sec velocity for water
• Sample Tube Compatibility
• Refer to ASTM Method D1192, D1066

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Proper Corrosion Products Sampling Technique

• Grab samples are not enough!
• Corrosion is dynamic and does not follow a
  regular pattern
• Transport is not uniform
• Varies with flow rates
• Crud bursts

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Proper Corrosion Products Sampling Technique

• A better alternative to grab sampling An
  integrated sample
• A measured flow through a filter for a
  significant period of time
• Collect insoluble and soluble products
• .45 micron filter
• Ion exchange filters
• Measure total flow

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Proper Corrosion Products Sampling Technique

• Analyze filtered products
• Acid digestion atomic absorption
• X-ray fluorescence
• Calculate average concentrations

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Corrosion Products Sampler Design Criteria

• Inlet Isolation Valve
• Sample Cooler
• Bypass Flow Stream
• Filter Isolation Valve
• Filter Purge
• Filter Holder
• Flow Control Circuit

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Inlet Isolation Valve

• Designed to minimize corrosion product buildup,
  ball or plug type if possible.
• Valve packing, stem and tip selected for the
  application

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Sample Cooler

• Must be capable of reducing the sample inlet
  temperature to below 122 F (50 C) with the
  correct sample line velocity
• Sample to be cooled using a single stage cooler
  having no internal weld joints on the tube side

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Bypass Flow Stream

• Used to establish the correct sample line
  velocity
• Helps to reduce and/or eliminate the effects
  caused by starting and stopping of sample flows
  through the sample filter assembly during routine
  changing of the filter paper

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Filter Isolation Valve

• Isolates the filter holder during assembly and
  disassembly
• The valve should be a ball or plug type

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Filter Purge

• Used to purge the filter holder assembly between
  corrosion product collections
• Eliminates cross contamination between samples
• Removes corrosion particulate that may have been
  released because of mechanical vibration during
  filter disassembly

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High Pressure Filter Holder

• Designed to house up to one particulate filter
  and five ion exchange filters
• The screwed type design will minimize mechanical
  agitation during assembly and/or disassembly.
• Sample taken at high pressure to ensure corrosion
  products are not removed by the pressure reducing
  valve
• Pressure rating of 3000 psia (206 bar) and
  temperature of 149 F (65 C)

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Conclusion

• Corrosion Products Samplers can be an invaluable
  resource to
• Locate the sources of corrosion products
• Determine the rate of corrosion
• Identify the type and cause of the corrosion
• Track the path of corrosion products

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Conclusion

• Improve plant safety equipment reliability
• Increase plant efficiency and capacity
• Reduce frequency between routine cleanings of
  plant heat exchanger equipment
• Reduce plant operating costs