Majalah Coating & Maintenance

ARTIKEL

PASSIVE FIRE PROTECTION APPLICATION WITH PLURAL-COMPONENT EQUIPMENT

Passive Fire Protection, or PFP, is a term that is frequently used in our industry today for describing technologies that delay or mitigate damage by fire to allow more time for protecting human life. PFP technologies operate without human intervention, focus on compartmentalization (preventing the spread of fire), and maintain the structural integrity of the vessel or building for a longer period of time-as opposed to active protection, which focuses on detection and suppression, including alarms and sprinkler systems. PFP systems include intumescents, cementitious materials, and proprietary boards or sheets. Each of these systems is engineered to protect the substrate.

This article will discuss aspects of intumescent plural-component PFP material application, including proper training, equipment required, and job profiles.

Instumescent PFP

Intumescent PFP materials are comprised of a resin matrix that contains a blend of thermally active chemicals formulated for fireproofing. An intumescent coating will expand (intumesce) 5 to 10 times its original thickness when exposed to fire, producing a carbonaceous char layer that insulates the substrate from the heat source by producing a char layer that protects it, and emitting gases that cool the surface area (Fig. 1).

Intumescents are applied in variety of industries. PFP materials are used in onshore and offshore applications, including gas/petroleum storage and distribution; petrochemical plants; storage tanks/vessels; refineries; power stations; steel structural beams and elements; valves; offshore platforms; and tanker vessels. The effects of heat on steel are significant, with steel losing half of its load bearing strength at 588 C (1000F)- the failure point for steel. The dangers associated with this damage are structural collapse, explosion of vessel contents, pipe fractures causing jet fires, and lack of containment that allows fire to spread.

Why specify intumescent PFP systems? In addition to their passive fire protection properties, they are robust and have good adhesion, high tensile and compressive strengths, and good resistance to impact and vibration. They have excellent weatherability and often do not require topcoats. PFP materials also have good chemical resistance and protect the substrate against corrosion due to extremely low water absorption. These systems often have a lower installed weight than other systems with similar properties, thus adding less weight to the final structure while providing maximum protection. PFP systems can be 40%-60% lighter than “lightweight” cementitious products.

Training and certification to apply these materials is utmost importance to achieve consistent properties and the correct functioning of PFP systems. Normally a company's employees must be trained to apply PFP materials. Most material suppliers provide qualified applicator certification to ensure the correct application of PFP materials. For example, one global paint manufacturer provides a two-day training course with hands-on application, including theory and practical training, sample preparation, and certification. The course trains and takes input from the applicator, fabricator, client, and material and equipment suppliers.

In the training course, applicators learn different application techniques. For example, one technique is to use carbon fiber hybrid mesh to allow higher thickness build and give anchorage and structural reinforcement to the instumescent material.

Surface Preparation for Intumescent

Even the best chemical system will not perform if the proper preparation steps are not followed. Important general preparation includes cleaning surfaces of dirt, oil, and grease to required standard SSPC-SO; blast cleaning to required standard Sa 2.5, with 50-75 microns blast profile; checking ambient conditions to ensure they conform to primer manufacturer's specifications (Qualified Primer List); and priming surface with approved primer, ensuring thickness is between 50 and 75 microns, and less than 100 microns at overlaps. Doing things correctly the first time always pays off and this is just one example of surface preparation. All of the steps recommended by the material manufacturer must be followed for a successful application.

Applying Intumescents

PFP materials can be applied with a trowel, a single-leg pump (hotpot), or with a plural-component system. Plural-component equipment allows the fastest production and gives the most control over application. Plural-component application also produces the least amount of waste of the three methods and allows solvent free application. The material suppliers must certify the equipment for the application. The components are made from materials that will provide the longest life during operation and help resist material abrasiveness while generating and maintaining the temperature and pressure required.

Plural-component equipment must be configured with the material supplier and certified for application of the specific material. Components designed and specified for use with these materials are ‘configured' or put together in an optimum way to allow the desired output. Components include pumps, heating systems, motors, tanks, hoses, and spray guns. The equipment system must be able to heat the material to the proper temperature to the gun, proportion the material to give proper ratio, and generate the correct pressure for mixing and spray pattern. The specialized chemistry in PFP systems requires a machine that is designed with these considerations in mind.

Intumescent Applications

Where are PFP materials being applied? All over the world. Many structures that can benefit from having PFP, including offshore rigs. Figures 5 and 6 show the application of an intumescent on the offshore platform “ Hammerfest ”.

In the U.S. PFP is being used on the steel structure for the new interchange station servicing subways, buses, and trains in New York City . The architect of the project specified intumescent PFP, and a steel structure workshop was conducted in La Coruna , Spain . Structural members have the PFP applied, and are then installed.

Large storage vessels in the petroleum industry are a target application area for PFP materials because they benefit from the fire protection and anti-corrosion properties of PFP materials. The adhesion to substrate and moisture-resistant nature of intumescents minimize the possibility of corrosion occurring due to moisture between the material and substrate.

Conclusion

Passive Fire Protection is a very specialized niche application that is growing worldwide due to the need for fire and corrosion protection that is low in installation weight. Companies who are certified to apply these materials have an advantage today because they have a lead in specialized markets and competition is currently limited. The only way to get involved is to become certified by one of the material suppliers and work to develop the market together. Proper training and technical support from the material and equipment suppliers are important components of a successful and on-time installation of PFP because PFP requires the combined expertise of the applicator, technical advisor, material supplier, and equipment supplier.

Acknowledgements

This article, an example of the combined expertise that is required for PFP training and installation, would not have been possible without the contributions of Herbert Mann, Rob Jansen, Werner Goetz, Uwe Tinz and Dirk Scherer of WIWA GmbH; Carlos Aguirre of Disnamair S.A.; and Jack Tay, John Yeoh, and Markus Federico of International Paint. The author thanks all for their contribution and support.

Reference

1. International Paint, “Pre-Application Key Points to Note,” on steps before applying PFP.

              • By : Murphy Mahaffey,
              • WIWA Wilhelm Wagner
              • GmbH & Co. KG

               

 

Protective Pipeline Coating Evaluation After Accelerated Cathodic Disbondment.

ABSTRACT    

Different pipeline coating materials applied on metal plate subjected to accelerated cathodic disbondment tests as per ASTM B117 and G 8 and the metal surface beneath cathodic disbondment of coating is subjected to micro analysis and thereby listing out and maximum and minimum corrosion and ranking the pipeline coating accordingly.

1. B. Duari, M.D, Rustech Products Pvt. Ltd., Mumbai – 400 093, India .

2. B. Chaudhuri, Formally Professor & Head, Department of Metallurgical & Material Engineering, Jadavpur University , Kolkata – 700 032, India

3. Debasis Sarkar, Scientific Officer, National Test House, Kolkata – 700 027, India.

 

Introduction

Burried M.S pipeline need to be coated so that those are not corroded. As the coated pipes are not 100% holiday free during installation and laying in the trench. Due to soil stress the holidays in the coating is further increased. Because of these holidays pipes are further protected by cathodic protection. If the coating system is not compatible with cathodic protection or if the cathodic protection system is not properly designed and operated, detoriation of adhesion of coating occurs and known as cathodic disbondment and three problem occurs.

•  Degradation & disintegration of coating occurs if coating are not resistant to alkali conditions (OH ˉ ions) which is produced by cathodic reaction at cathode (i.e. at pipeline).
•  If there is excessive protective current during C.P, disbondment of coating due to generation of hydrogen on pipe & beneath coating. The hydrogen will try to lift the coating and causing disbondment and premature failure of coating.
•  Detoriation of coating due to increased ion flow known as Electro endosmosis. Less permeable coating are resistant to Electro endosmosis than more permeable coating.

In order to check the condition of surface of the coated pipe (cathode) microscopically after cathodic disbondment, different coating material 3 layer PE, coal tar enamel, hot applied coal tar tape, high build epoxy, coal tar epoxy, polyurethane cold applied PE tape applied on metal plate and subjected to 500hrs, 1000hrs, 1500hrs, 2000hrs salt spray test as per ASTM B 117 and further 28 days cathodic disbondment test as per ASTM G 8 are carried out. Further after cathodic disbondment the corroded area is subjected to micro-structure analysis with the help of electron microscope to the find out / list out max and min corrosion and rank the coating accordingly.

Preparation of sample
MS plates are shot blasted after which different coating materials are applied.
•  Coal Tar Epoxies, High Build Epoxies, Polyurethane are applied by airless spray technique.
•  Cold Applied PE Tape are applied by pressure techniques.
•  Coal tar Tape are applied by torching method.
•  Coal Tar Enamel are applied by flushing techniques.
•  3 Layer PE coating applied by cross head extrusion process on a shot blasted pipe from which the requisite sizes are taken out.

Procedure of testing

The sample are subjected to exposure in salt fog of concentration 5% NACL solution for 500hrs, 1000hrs, 1500hrs and 2000hrs.

All every interval of 500hrs, 1000hrs, 1500hrs and 2000hrs the samples of each coating materials are withdrawn from salt spray chamber and are again subjected to cathodic disbondment for 28 days at 1.5 potential at 30 ± 5° C.

For cathodic disbondment test method followed as per ASTMD G 8 where two individual cells are made having electrolyte concentration 3% (NACL). A 6mm hole is drilled out at the centre of each cell to remove the coating material upto the base metal substrate as a predamaged area which act as cathode. Here platinum electrode is used as anode and reference electrode is immersed inside the cell to measure the continuous potential for 28 days.

After conducting cathodic disbondment test for 28 days, the coating is removed from the corroded area and the steel portion of that area is subjected to microstructure analysis with the help of scanning electron microscope (SEM) which is again compared with the original steel plate.

The test is carried out for every 500hrs, 1000hrs, 1500hrs and 2000hrs salt spray test followed by cathodic disbondment test for each coating materials separately to justify cathodic disbondment.

Discussion regarding the SEM images :

For 500 Hours :

The images of the surfaces under experiment after salt spray (fog) test for 500 hours (as per ASTM B 117) and 28 days cathodic disbondment test are given below.

___

___3 Layer PE____ Coal Tar Tape___ Coal Tar Enamel__ High Build Epoxy

__

_Coal Tar Epoxy___ Polyurethane __Cold Applied Tape

Seven photographs of the collected surface with following coating,

1) 3 Layer PE, 2) Coal Tar Tape, 3) Coal Tar Enamel, 4) High Build Epoxy, 5) Coal Tar Epoxy, 6) Polyurethane, 7) Cold Applied Tapes are given below. The images are compared and following observation are made.

After 500 hrs the intensity of corrosion is more or less comparable. However, 3 Layer PE coating shows very less corrosion compare to others. Corrosion is maximum in cold applied tapes as max disbonding is observed during macro-analysis as discussed earlier. Polyurethane coating also shows very intense corrosion but comparatively lesser than cold applied tapes. The closest coating in regard to corrosion protection comparable to 3 Layer PE are Coal Tar Tapes and Coal Tar Enamel. High Build Epoxy and Coal Tar Epoxy show greater corrosion than Coal Tar Enamel but lesser than Polyurethane and Cold Applied Tapes.

After 1000 Hours :

Like 500 hrs. after 1000 hrs., of salt spray & cathodic disbondment same procedure is followed & seven images of the surface under different coating are compared and following observation are made.

___

___3 Layer PE ______Coal Tar Tape ____Coal Tar Enamel __High Build Epoxy

__

__Coal Tar Epoxy ____Polyurethane ____Cold Applied Tape

3 Layer PE shows lowest corrosion on the surface. The surface roughness generated as a result of corrosion is also very small comparing to others. Coal Tar Tapes, Coal Tar Enamel show more aggressive corrosion on the surface. Chunky layers of iron oxide are shown in Coal Tar Enamel coating. HBE and Coal Tar Epoxy also exhibit very intense corrosion, intensity being more in case of HBE. Corrosion products are large chunks of iron oxide. Damage is most vigorous in case of PU and Cold Applied Tapes. The damage of the surfaces are very much prominent even in macro-analysis.

The corrosion products are very large and chunky layers of iron oxides.

After 1500 hours :

After 1500 hrs. same procedure followed like 500 hrs. and images are compared.

___

___3 Layer PE _______Coal Tar Tape ___Coal Tar Enamel ___High Build Epoxy

_Coal Tar Epoxy ____Polyurethane __Cold Applied Tape

Paint layer in 3 LPE coating is still sticking to the surface. Incase of Coal Tar Tapes and Coal Tar Enamel the formation of iron oxides are visible on the surface. Small flex of iron oxides can be seen from the images. Coal Tar Epoxy shows lesser rough surface but it has resulted due to removal of generated iron oxide layer. HBE and PU show very high corrosion resulting in large lumps of iron oxides. Most vigorous corrosion takes place incase of Coal Applied Tapes. The micrograph shows layers of iron oxide coming out of the surface.

After 2000 hours :

After 2000 hrs. same procedure followed like 500 hrs. and images are compared.

___

____3 Layer PE _____Coal Tar Tape_____Coal Tar Enamel __High Build Epoxy

__

__Coal Tar Epoxy_____Polyurethane ___Cold Applied Tape

Following the pervious trend, 3 Layer PE shows the best corrosion resistant properties in the same environment under experiment. It shows very less corrosion. It also earlier shows min cathodic disbondment. Coal Tar Tape is showing more corrosion than 3 Layer PE. In case of Coal Tar Enamel, nature of damage or corrosion is different. In the centre of Coal Tar Enamel, the

corrosion is deep and penetrating. In HBE corrosion is comparable to Coal Tar Epoxy and Polyurethane. For Cold Applied Tapes the trend is also similar, it shows very vigorous corrosion.

Inferences :

With reference to the discussions above, we can conclude that 3 Layer PE shows best result in this particular corrosive environment. Whereas, Coal Applied Tapes shows greatest (maximum) corrosion.

Till 500 hrs salt spray and subsequently cathodic disbondment test all the coatings show more or less comparable corrosion property but after 1000 hrs all the coatings other than 3 Layer PE, Coal Tar Tapes, Coal Tar Enamel & Coal Tar Epoxy, other coatings degrade radically.

From the best to the worst we can rank the coatings as follows :

•  3 Layer Polyethylene
•  Coal Tar Tapes
•  Coal Tar Enamel
•  Coal Tar Epoxy
•  High Build Epoxy
•  Polyurethane
•  Cold Applied PE Tapes

 

References :

  1. ASTM G 8 – 03 “ Standard Test Method for Cathodic Disbonding of Pipe Line Coating”.
  2. ASTM B 117 – 02 “Standard Practice for Operating Salt Spray (Fog) Apparatus.”.
  3. Corrosion Beneath Disbonded Coatings : A Review by J. A. Beavers and N. G. Thomson (A NACE Publication)

 

Acknowledge :

The authors world like to thank the Head, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata for permission to use the optical and scanning Electron Microscopes of the department in carrying out the present work.

              • By : B. Duari, B. Chaudhuri
              • Debasis Sarkar

             

 

Menentukan Kadar Garam Terlarut Pada Permukaan Substrate Yang Dilakukan Sebelum Aplikasi Coating

Pengantar :

Pada majalah edisi yang lalu redaksi menurunkan tulisan perihal garam terlarut dipermukaan beserta kandungan yang diizinkan berdasarkan IMO MSC 215 PSPC dan berikut ini akan dikemukakan metoda yang dapat digunakan untuk mengkoleksi kandungan garam tersebut dan pada edisi yang akan datang adalah metoda pengujian yang dapat dilakukan untuk menentukan kadar garam terlarut tersebut. Artikel ini diambil dari SSPC. Disamping itu ada beberpa informasi tambahan yang akan disampaikan berdasarkan penelitian yang dilakukan ( JPCL vol.27/nr.2, February 2010). Informasi tersebut adalah :

  • Kontaminasi ion chlorida ( Cl - )lebih kritis dibandingkan dengan ion sulfate( SO 4 2- )
  • Coating system yang menggunakan Zinc-rich sebagai primer akan lebih toleranterhadap kontaminasi garam
  • Coating system yang diekspose dilingkungan atmospheric akan lebih toleran dibanding yang selalu terendam
Sedangkan quantity kadar garam yang diizinkan bervariasi antar beberapa peneliti seperti yang ditampilkant pada Tabel di bawah ini :

Standard yang dapat digunakan adalah :

  1. Measurement of Chloride on Steel Surfaces prepared for Painting–Ion Detection Tube Method (ISO 8502-5:1998)
  2. Extraction of Soluble Contaminants for Analysis – The Bresle Method (ISO 8502-6:1995)
  3. Field Method for Conductometric Determination of Watersoluble Salts (ISO 8502-9:1998)
  4. Field Method for the Titrimetric Determination of Watersoluble Chloride (ISO 8502-10:1999)
  5. SSPC Guide 15, “Field Methods for Retrieval and Analysis of Soluble Salts on Substrates” describes methods for sampling and analysis of soluble salt contamination. Guide 15 is contained in Volume 2 of the SSPC Painting Manual, “Systems and Specifications,”

 

Selamat membaca.

How Do I Test for Soluble Salt Contamination?

There are two widely accepted techniques for testing salt contamination. The technique that you select is based on whether you want to know both the quantity and the type of water-soluble salt that is on the surface or whether you just want to know if water-soluble salts are present. The first technique is known as “specific ion detection;” the second technique is called “conductivity.”

 

What is Specific Ion Detection?

Specific ion detection will tell you whether a specific type of water-soluble salt is on the surface (for example, chlorides, sulfates, ferrous ions, etc.) and how much of each one is there (as long as you test for them). If you select this testing technique you will need to sample the surface, then test the sample for each of the water-soluble salts that you are concerned may be on the surface.

 

What is Conductivity?

Water-soluble salts will increase the electrical conductivity of pure water. For example, salt water will conduct electricity a lot better than distilled water. Therefore, if you sample the surface with pure water and test the water sample, an increase in electrical conductivity indicates that the water has extracted salts from the surface. However, conductivity testing will not be able to tell you what type of salt is on the surface, only that there is some type of water-soluble salt that is causing the electrical conductivity of the water to increase. Some individuals will assume that an increase in conductivity is an indication that chloride is on the surface, and they will “convert” the conductivity to a chloride concentration. These individuals are assuming a worst-case scenario (i.e., being conservative), since chloride is considered the most detrimental of all water-soluble salt contamination.

 

How Do I Test for Specific Ions and Conductivity?

There are a variety of methods that can be used to sample the surface, and there are several methods that can be used to test the collected sample. Unless the project specification tells you what test method to use, the first step is to select one. SSPC Technology Guide 15, “Field Methods for Retrieval and Analysis of Soluble Salts on Steel and Other Non-Porous Substrates” describes the most commonly used extraction and testing methods. You will be learning about several of them. But first, you will need to decide if you want to test for specific ions or test for conductivity.

 

Selecting a Field Sampling and Testing Method

If you select “specific ion detection” there are several field sampling techniques and several field testing methods to choose from. The ones we will focus on in this Module will tell us whether chlorides, sulfates and ferrous ions are present and how much of each is there. If you select “conductivity” there are several field sampling techniques to choose from, but only one field testing method that can be used.

To select a test method, first ask yourself, “What does the project specification require?” If the specification does not require a specific method, then you can select from any of the methods available. This module describes several Surface Contamination Analysis Test (SCAT) kits. The sampling and testing methods and the possible combinations of SCAT kits are shown in the charts below.

Chart 1 – Combination of Sample Collection and Testing Methods

 

Method of Sample Collection

Method of Sample Testing

A. Surface Swabbing

 

•  Quantab® Chloride Titrator Strip

•  Kitagawa® Chloride Titrator Tube

•  EM Quant® Iron Strip (ferrous ion)

•  Conductivity

B. Latex Sleeve (Chlor-Test® Kit)

 

•  Kitagawa® Chloride Titrator Tube

•  Bresle® Kit Drop Titration for Chloride

•  EM Quant® Iron Strip (ferrous ion)

•  Conductivity

•  Turbidity (sulfate)

C. Latex Cell (Bresle Patch™ and Bresle Sampler®)

 

•  Quantab® Chloride Titrator Strip

•  Kitagawa® Chloride Titrator Tube

•  Bresle® Kit Drop Titration (chloride)

•  EM Quant® Iron Strip (ferrous ion)

•  Conductivity

M ETHODS OF S AMPLE C OLLECTION

Before you test a sample for soluble salt contamination, you will need to collect a sample or set of samples from the surface. This section describes three methods of collecting samples from a surface for testing. Remember, SCAT stands for Surface Contamination Analysis Test.

Surface Sampling Method A: Surface Swabbing (Swab SCAT Kit)

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The surface swabbing technique was one of the first sample collection methods available. The amount of soluble salt contamination actually sampled using the surface swabbing technique (better known as extraction efficiency) is relatively low, compared to some of the other methods we will be discussing. Despite its limitations, surface swabbing is still a viable technique for sample collection. The KTA Swab SCAT kit contains all of the necessary equipment you will need to collect a sample from the surface, and then test the sample for chloride, ferrous ion and pH.

Step 1: Purify the Extraction Water

Before you collect a sample from the surface, make sure that the water you will use does not already contain chloride. You have a couple of options here.

Option 1: Demineralizer bottles are available from Hach (or from KTA) so that you can purify regular tap water in the field. To use the Hach demineralizer bottle, simply fill it with tap water and shake it gently. Open the valve in the lid and squeeze the demineralizer bottle until the desired quantity of water is dispensed. Close the lid valve. The demineralizer bottle will need to be replaced

when the resin beads inside the bottle change in color from purple to gold.

Option 2: Many grocery stores sell plastic, one-gallon containers of distilled water. This water can also be used. However, be certain that the water is truly free of any detectable chloride by placing a few drops (1 or 2 milliliters) into a clean plastic beaker and testing it using the Quantab® Titrator Strip (see instructions on using and reading the Quantab® strip). This is called “running a blank.” If the Quantab® test strip does not indicate the presence of chloride, then the distilled water is okay to use for the extraction. If you test the extraction water, be sure to document the results of your test (e.g., “chlorides, if any in the blank sample were below the detection limit of the test strip, which is 28 PPM”). Note: The detection limit of the Quantab® Titrator Strips will vary depending on the batch. The detection limit is the lowest PPM value listed on the conversion chart.

Step 2: Measure an Area for Sampling

Select a test area based on the project specification requirements or other instructions. If no guidance is provided, then you'll need to select test areas based on likely areas of contamination. Typical sample locations might be on the bottom of a vessel, or in areas where rust and contamination are present. Once a test area is selected, measure and draw a square on the surface using a chloride-free pencil. The square can be any size, as long as you measure and record its dimensions. A 4" x 4" sample area is convenient, because it converts to approximately 100 square centimeters (1" = 2.54 cm). Record the actual size of the test area (in cm 2 ) using the formula: In 2 x 2.54 2 = cm 2

Text Box:

Example: Area tested was 4" x 4" (16 in 2 ) x (2.54 2 ) = 103.2 cm 2

Step 3: Measure the Amount of Sampling Water

3-1 Dispense the desired quantity of demineralized or distilled water into the plastic graduated cylinder (included). You can use any amount of water, but if you use too much water, you may dilute your sample so much that you will not get a reading. Therefore, for larger areas 10 milliliters is recommended; for smaller areas like 4” x 4”, use 5 milliliters of water. Whatever quantity you use, make sure to record it on the data chart.

3-2 Pour all of the water from the graduated cylinder into the small plastic beaker.

Example: Quantity of water used was 5 mL

Step 4: Sample the Surface

4-1 Using a pair of tweezers (included) or latex surgical gloves take a cotton ball out of the zip lock bag.

4-2 Immerse the cotton ball in the sampling water inside the small plastic beaker. Withdraw the moistened cotton ball.

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4-3 Swab the entire measured area on the surface. Be careful not to lose too much water in the process. The cotton ball should be wet, but not saturated or dripping.

4-4 After swabbing the entire measured area, place the cotton ball back into the beaker and swirl it in the water. Be careful not to touch the water or the cotton ball with your unprotected fingers, as they can contaminate the sample. Wring-out most of the water from the cotton ball, then swab the same measured area a second time. Repeat this process several times (minimum of 4 times) to ensure

that any salts on the surface are dissolved in the water, collected on the cotton ball and transferred into the plastic beaker.

4-5 After the final swabbing, swirl the cotton balls in the water for at least two minutes. You are now ready to test the sample you collected from the surface for chloride, ferrous ions and/or conductivity. You can also test the sample for pH if you desire. If you selected this method of sample collection, you can now proceed to Section 2 of this module for instructions on how to test the sample(s) you have collected.

4-6 You can run a “blank” sample to confirm that the water, containers and cotton balls are not the source of salt contamination. To run a blank sample, measure and dispense the same quantity of water used in Step 3-1 into a second clean beaker. Remove a new cotton ball from the bag (using tweezers or latex gloves), place it in the beaker of water, then swirl the cotton ball in the water for at least

two minutes. Test this sample using the same procedure you intend to use on the actual sample collected from the surface. Deduct any reading you obtain on the “blank” from the sample collected during the surface extraction.

Surface Sampling Method B: Latex Sleeve (Chlor*Test TM SCAT Kit)

The Chlor*Test TM SCAT Kit contains five latex sleeves and five bottles of Chlor*Extract TM solution that are used for collecting a sample from the surface. The extraction efficiency of this method is better than the swabbing method.

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Step 1: Prepare the Latex Sleeve

1-1 Remove the cap from the Chlor*Extract TM solution bottle and pour the entire contents into the Chlor*Sleeve TM

1-2 Peel the white, pressure sensitive adhesive strip backing from the latex

sleeve to expose the adhesive.

1-3 Remove the air from the latex sleeve by squeezing it between your fingers and thumb. Be careful not to spill any of the solution while you are evacuating the air from the latex sleeve.

Step 2: Attach the Latex Sleeve to the Test Surface

2-1 Select a test area based on the project specification requirements or other instructions. If no guidance is provided, then you'll need to select test areas based on likely areas of contamination. Typical sample locations might be on the bottom of a vessel, or in areas where rust and contamination are present. Once a test area is selected, firmly affix the latex sleeve to the surface by attaching the adhesive end of the sleeve to the test surface. The latex sleeve can be attached to horizontal or vertical surfaces, or even overhead.

2-2 Press firmly around the perimeter of the contact area to ensure you have a

good seal between the surface and the latex sleeve

Step 3: Sample the Surface

3-1 With one hand, lift and hold the free end of the latex sleeve upright so that the extraction solution comes in contact with the test surface.

3-2 Use your fingers on the other hand to massage the solution (through the latex sleeve) for at least 2 minutes. This helps to extract the contamination from the surface into the solution.

Step 4: Remove the Latex Sleeve from the Surface

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4-1 After you complete Step 3, carefully remove the latex sleeve from the test surface. Make sure that the extraction solution returns to the bottom of the latex sleeve before you remove it from the surface. For overhead or vertical surfaces, gravity will put it there. For horizontal surfaces, you will need to slide your fingers along the outside of the latex sleeve and push all of the solution into the closed end of the sleeve before removing it from the surface.

4-2 After removing the latex sleeve from the surface, place it through the hole in the kit box lid, with the open end of the sleeve up. The sample will remain in the bottom of the latex sleeve. You are now ready to test the sample you collected from the surface for chloride, ferrous ions and/or conductivity. If you selected this method of sample collection, you can now proceed to Section 2 of this module for instructions on how to test the sample(s) you have collected.

Surface Sampling Method C: Latex Cell

(Bresle Patch TM and BresleSampler®)

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There are two latex cells that can be used to collect a sample from the surface. They are both named “Bresle.” The Bresle Patch TM is an adhesive latex cell. The sampling area of the latex cell is 12.25cm 2 and is square in shape. The BresleSampler® is also an adhesive latex cell. The sampling area of this latex cell is 12.5cm 2 and is round in shape. Since the procedure for collecting a sample from the surface using these two latex cells is essentially the same, only the

Bresle Patch™ is illustrated.

Step 1: Purify the Extraction Water

The KTA-Bresle SCAT Kit contains a bottle of Extraction Liquid. If you purchased a KTA-Bresle SCAT Kit and you are going to use the Extraction Liquid, then you can proceed to Step 2. If you are going to use water instead of Extraction Liquid, then make sure that the extraction water you will use does not already contain chloride before you begin to collect a sample from the surface. You have a couple of options here.

Option 1: Demineralizer bottles are available from Hach (or from KTA) so that you can purify regular tap water in the field. To use the Hach demineralizer bottle, simply fill it with tap water and shake it gently. Open the valve in the lid and squeeze the demineralizer bottle until the desired quantity of water is dispensed. Close the lid valve. The demineralizer bottle will need to be replaced

when the resin beads inside the bottle change in color from purple to gold.

Option 2: Many grocery stores sell plastic, one-gallon containers of distilled water. This water can also be used. However, be certain that the water is truly free of any detectable chloride by placing a few drops (1 or 2 milliliters) into a clean plastic container and testing it using the Quantab® Titrator Strip (see Step 5 for instructions on using and reading the Quantab® strip). This is called “running a blank.” If the Quantab® test strip does not indicate the presence of chloride, then the distilled water is okay to use for the extraction. If you test the extraction water, be sure to document the results of your test (e.g., “chlorides, if any in the blank sample were below the detection limit of the test strip, which is 28 PPM”). Note: The detection limit of the Quantab® Titrator Strips will vary dependingon the batch. The detection limit is the lowest PPM value listed on the

conversion chart.

Step 2: Prepare the Latex Cell

Select a test area based on the project specification requirements or other instructions. If no guidance is provided, then you'll need to select test areas based on likely areas of contamination. Typical sample locations might be on the bottom of a vessel, or in areas where rust and contamination are present.

2-1 Once a test area is selected, peel the label backing from the adhesive side of the latex cell and discard the label. This will expose the adhesive.

2-2 Carefully press the center of the non-adhesive side of the patch with your finger(s) to “punch-out” the foam square (or circle in the case of the

BresleSampler®) to create a “void” area. This foam piece can be discarded.

2-3 Attach the latex cell to the test surface (adhesive side down).

2-4 Press firmly around the foam border of the latex cell to ensure a good seal.

You have now created a “sampling cell” that will retain the extraction solution

once it is placed inside.

Step 3: Evacuate the Air from the Latex Cell

Using an empty 5cc syringe, insert the syringe needle through the top of the foam border, and then continue to slide the syringe needle into the latex cell until it is visible through the semi translucent top. Withdraw the syringe plunger to evacuate the air from inside the cell. This will help prevent over-pressurizing of the patch during sample collection. You will notice that a vacuum is created inside the cell, because the top of the cell will be sucked in towards the test surface. Depending on the quality of the seal around the foam border, this vacuum may or may not hold. It is okay if the cell does not maintain the vacuum. Carefully remove the syringe needle from the cell by sliding the needle back through the foam border.

Step 4: Measure the Amount of Sampling Water or Extraction Liquid

4-1 Dispense some of demineralized water or Extraction Liquid into a clean plastic beaker or other small container.

4-2 Draw water or liquid into the syringe through the needle. Over fill the syringe, hold the syringe upright, tap the syringe then discard the excess by slowly depressing the syringe plunger until the desired quantity is obtained (e.g., 2cc). This procedure will also get rid of the air. Never discard liquid back into the container, as you may cause it to become contaminated.

4-3 You can use any amount of liquid (1cc to 3cc), but the more you use, the more you will dilute your sample. Make sure to record the actual quantity of sampling liquid that you used. Note that milliliters (mL) and cubic centimeters (cc) are the same value.

Example: Quantity of water used was 2cc (2 mL)

Step 5: Collect the Sample

5-1 Carefully inserts the syringe needle through the top of the foam border, then continue to slide the syringe needle into the void area of the cell until it is visible through the semi-translucent top.

5-2 Slowly injects the liquid into the cell. Once all of the liquid is injected, carefully slide the needle back through the foam border, but do not remove the needle from the cell.

5-3 Carefully rubs and taps (using moderate pressure) the top of the cell for 15-20 seconds. This “agitates” the liquid inside the cell and helps to extract the salt contaminants.

5-4 Slide the needle back into the cell and evacuate the solution. You do not

have to evacuate all of the solution . Slowly inject the liquid back into the cell and agitate the surface again. Repeat this procedure a minimum of 3 times. After the final time, evacuate as much of the liquid from the latex cell as possible using the syringe. Completely remove the syringe needle from the cell by sliding the needle back through the foam border.

Text Box:

5-5 Empty the contents of the syringe into a small plastic beaker or other small plastic container/vial. You are now ready to test the sample you collected from the surface for chloride, ferrous ions and/or conductivity. If you selected this method of sample collection, you can now proceed to Section 4-2 of this module for instructions on how to test the sample(s) you have collected.

If you are going to collect additional samples using the same syringe, you must thoroughly

flush the syringe and needle with distilled or deionized water. Otherwise, you will cross-contaminate samples. Properly dispose of all syringes and syringe needles so that they do not injure anyone.

 

 

 

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