Whether building new process lines or renovating existing lines, capital and operating and maintenance (O&M) cost estimates are important for project planning and implementation. The following will provide an overview of the classes of capital cost estimates. Different levels of capital cost estimates provide key input for decisions over the life of surface finishing projects from initial concept development through project selection and budgeting and on through completion of engineering design, procurement, and implementation phases. Understanding cost estimating methods and expected ranges of accuracy over a typical project life cycle is important for project financial considerations and communications and for decision support.

Table 1 is adapted from the AACE International practice guideline 18R-97 which applies the principals of cost estimating classification for process industry engineering, procurement, and construction projects (see reference below). This guideline is applicable for surface finishing process projects. Table 1 shows five AACE cost estimate classifications with the following information and characteristics:

• Comparison of the five AACE classes to the three traditional, widely-used ANSI cost estimate classifications.
• Typical uses of each class of estimate for support, from project conceptualization and development through project delivery and completion.
• Level of project definition, expressed as a percentage of engineering and general project (e.g., scope, schedule, work breakdown structure, contracting strategy, escalation strategy) documentation development. For process projects, the engineering development typically progresses:
  1. From early definition, including project location and constraints, general scope, processes and chemistries, production requirements and work envelopes, and process flow diagrams (PFDs).
  2. Through process layouts and implementation phasing plans (if applicable), piping & instrument diagrams (P&IDs), utility flow diagrams, mass and energy balances, building integration plans, and equipment schedules.
  3. Through detailed, multidiscipline engineering plans (structural, mechanical, electrical, I&C) and drawings (3D and 2D), specifications and data sheets, functional descriptions, O&M and commissioning plans, and lists of spare parts included in the project.
• Expected Range of Accuracy: The accuracy ranges for each estimate class represent a range around an estimated expected cost value for a specific scope, including appropriate contingencies. The +/- percentage ranges represent an 80% confidence interval that completed actual project costs for a given scope will fall within the estimated ranges (assuming project implementation at specific location, under planned schedule, etc.). For each estimate class, the ranges for the low expected actual cost and high expected actual cost represent typical variances that result from individual project complexity and level of definition. These ranges also vary with estimating methods and engineering and estimating experience applicable for a specific surface finishing project. The ranges are asymmetric with higher percentage variations on the high costs. This is due to historical cost outcomes for specific project scopes that demonstrate factors combine to make the magnitude of probable final project cost increases from estimated values more likely than cost decreases.
• Other Terms: These other commonly used estimate names are approximately correlated with the AACE estimate classes. Use of these other terms is not always specified with expected ranges of accuracy and may differ in meaning for different circumstances.

TABLE 1: Summary of AACE International Cost Classifications and Expected Ranges of Accuracy

NOTE: This table is based on AACE International Recommended Practice No. 18R-97: Cost Estimate Classification System – As Applied in Engineering, Procurement, and Construction for the Process Industries. TCM Framework: 7.3 – Cost Estimating and Budgeting (Rev. March 6, 2019).

In progressing from AACE Class 5 to Class 1 estimates, methodologies typically begin with more stochastic approaches (e.g., estimating from previous similar project costs using parametric calculations based on key quantities) and transition to more complete deterministic methodologies (e.g., semi-detailed to full line item detailed estimates). Appropriate contingencies are assumed to be included in each AACE class of estimate. Contingencies are separate from allowances.  Contingencies account for non-specific/uncertain scope items and project risks. Contingencies are best estimated based on experience and review of similar past project estimated scope and costs compared to completed project actual costs with the same scope. When known scope items for a planned project are not included in stochastic extrapolations, or are not yet accounted for in line item cost details, specific allowances should be included in estimates for these known but mostly unquantified scope items (e.g., existing process demolition that was not part of a previous project used for a Class 5 estimate where the new project has process demolition; interconnecting process electrical or mechanical not yet detailed in a Class 4 or 3 estimate, etc.).

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Integrated Technologies, Inc. is an industry-leading engineering, design, and consulting solutions firm based in Burlington, VT. We offer project planning and development, full-service engineering and design, project and construction management, and services during construction to the surfacing finishing and industrial manufacturing industries. 

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Part 7 of the seven-part series on material selection for chemical process equipment focuses on the benefits of proper material selection for chemical process equipment and process areas.  In Parts 1 through 5 of this series, a diverse range of materials for chemical process applications was summarized, including metals, plastics, rubbers and elastomers, fiberglass reinforced plastics (FRP), advanced composites, technical ceramics, glass, and other materials. Material options may also include a range of liners and coatings that can extend the application range of lower-cost base materials to chemical environments that would not be recommended for the base materials.  Powder coat and paint systems are also important for overall process installations to protect exposed surfaces from relatively low levels of exposure to process chemistries and for overall system aesthetics.

Selecting and installing appropriate and cost-effective chemical process equipment and process area materials results in substantial life cycle cost savings.  For successful life cycle cost savings and benefits from proper equipment and systems materials, comprehensive engineering is important to assure that proper material selection for minor components is not missed (e.g., seal materials). Life cycle cost savings can be achieved either through initial selection of appropriate robust materials or, in some cases where value engineering and applications experience provide compelling justification, using lower cost and shorter-life materials where more frequent changeout provides cost advantages without significant disadvantages (see Part 6).

More robust chemical process equipment and process area materials are logical choices, where initial installation of materials pays off quickly compared to installing much shorter-life materials and then paying for removal and replacement with more robust materials.  Other savings can be far more substantial than the material/equipment removal and replacement purchase and installation savings alone. These other cost savings can include:

• Avoiding process shutdowns, fluid removal and replacement, and other production impacts for replacement of equipment and systems that degrade or fail early.
• Avoiding paying for quick turnaround and/or off-shift work premiums for equipment/systems removal and replacement.
• Avoiding special access and safety measures for equipment/systems removal and replacement with process solutions in place.

In addition to long-term cost-effectiveness, more durable materials for chemical process equipment and systems can also provide additional benefits (depending on application specifics):

• Enhance production performance and reliability
• Reduce maintenance requirements for repairs
• Reduce risks associated with equipment failures
• Reduce waste generation and conserve raw materials
• Help maintain positive plant image for workers and customers
• Achieve overall energy savings
• Provide flexibility for future process modifications, including potential change out of process chemistry.

Good engineering work for selection and implementation of materials for chemical process equipment and systems provides significant life cycle savings plus a range of other benefits.

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Integrated Technologies, Inc. is an industry-leading engineering, design, and consulting solutions firm based in Burlington, VT. We offer project planning and development, full-service engineering and design, project and construction management, and services during construction to the surfacing finishing and industrial manufacturing industries. 

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Part 6 of the seven-part series on material selection for chemical process equipment focuses on selection/evaluation considerations, including, and in addition to, material compatibility for specific process chemistries. Overview provided a listing of surface finishing chemical process equipment and systems that typically need material selection for various levels of exposure to process chemistries. Part 1 (Metals), Part 2 (Plastics), Part 3 (Other Materials), and Part 4 (Liners & Coatings) provided overviews of the broad range of materials available for different chemical process equipment applications. Part 5 (Paint & Powder Coating) overviewed selection of paint and powder coatings for process equipment and process system/area materials. This Part 6 starts with considerations for process conditions for candidate materials for evaluation.

Identify Process Conditions and Materials for Chemical Process Equipment

In addition to identifying chemical process equipment that will meet process performance criteria (e.g., pumping rates) and mechanical/electrical and other non-chemical service requirements for a new or existing surface finishing process line/system, consider the following for the chemical process equipment materials to meet application-specific process chemistry service needs:

1. Determine process chemistry and temperature ranges: For each process area, estimate/verify process chemistry and temperature ranges over the life cycle for the process solutions. This should include initial solution mixing and temperatures that may result from exothermic reactions, solution variations during production, contaminant build-up in solutions, make-up chemistry additions, cleaning solutions, and any temporary or emergency uses for alternate process chemistries. Low concentration ranges and low temperatures are important to consider – in some cases certain materials are more effected at the low temperature or low concentration ranges for a process solution.
2. Exposure Conditions: Determine the type of exposure to the process chemistries that may include constant immersion, periodic wetting/immersion, intermittent splashing, or constant or periodic exposure to mists and vapors. Be sure to consider additional corrosion potential at liquid/air interfaces (e.g., open tank liquid surface level range).
3. Identify candidate materials (including materials with linings and/or coatings): To identify chemical process equipment materials that might satisfy process chemistry and temperature conditions, consider relevant applications experience, recommendations from process chemistry manufacturers and equipment manufacturers, and chemical resistance charts from reputable sources. Be very cautious of any extrapolations beyond referenced data points, and only assess the material resistance to a chemical mixture (e.g., etch solutions with mixed acids) with data that is relevant for the specific chemical solution mixtures. In cases where sufficient chemical resistance data is not available for specific materials, consider accelerated materials testing for the specific chemistries at elevated temperatures.

Consider Selection/Evaluation Factors

For candidate chemical process equipment/systems and various material options, key selection/evaluation factors include:

1. Design Life: A typical design life for a surface finishing process line/system is in the range of 20-25 years. Overall line/system design life can be much shorter in cases including relatively short-term pilot or demonstration lines/systems, interim duty before facility renovation or relocation, or rapid technology advancement/changeout. Key equipment and systems, such as process tanks, process piping systems, and process structural support systems, should be adequate for the overall system design life. Process equipment components, such as sensors (e.g., pH, level, conductivity, etc.), will typically have shorter equipment-specific design life with planned replacement intervals within the overall process line/system design life.
2. Cost: Cost evaluations should include total installed capital cost and balance of life cycle costs. In addition to the purchase price differences for chemical process equipment with different material options, the total installed capital cost can also vary due to different shipping, handling, and installation costs between material options (e.g., metal tanks that are much heavier than thermoplastic tanks and have different support, handling, and installation requirements).  Also, accessories and other equipment may vary between material options and can significantly impact total installed cost (e.g., chemical process equipment using a less robust material may require added monitoring sensors and controls, additional containment provisions, etc.). The balance of life cycle costs can vary significantly due to differences in equipment maintenance and different replacement intervals for the chemical process equipment material options. It is common to select less robust materials such as 316 stainless steel (SS) vs tantalum for equipment such as heat exchangers where the cost multiplier could be as much as 10x with a planned replacement schedule. For instance the expected life of a SS heat exchanger may be 10 years vs 30 years for tantalum, but if the cost differential is very high then selection of SS material with a planned replacement schedule could provide greater value with acceptable performance.
3. Operations and Maintenance (O&M) impacts: Consider if the material has negative impacts on process chemistry (e.g., metals dissolving or solvents leaching) and if the material needs to be eliminated from consideration for more inert materials or if material treatment (e.g., metal passivation or PVC solvent leaching) and/or process chemistry purification processes are applicable and feasible. If a less robust material means more frequent equipment changeout, consider impacts not only to technician labor and equipment replacement but also potential process shutdown.
4. Implementability: Evaluation of implementability for different chemical process equipment materials includes procurement lead time (OK for project schedule?) and if there are any special construction/installation requirements or start-up and commissioning requirements. Consider whether a material is a standard product of the manufacturer and whether it has a proven track record in relevant applications.
5. Coordination: Consider other project and plant equipment and systems and potential benefits for coordination/standardization for chemical process equipment to simplify spare parts inventories and maintenance requirements.
6. Flexibility: More robust materials may provide flexibility for future process modifications, including potential change out of process chemistry.
7. Safety and Health: Consider any differences in material-specific requirements and potential risks to safety and health during construction/installation, operation, and maintenance.
8. Energy and Environmental: Consider client- and project-specific energy and environmental factors and whether alternate chemical process materials provide different impacts.

Follow-up After Material Selection

Follow-up after material selection for surface finishing process equipment and areas is important for project success. Follow-up considerations include:

1. Verify that the material selections are still valid after any project changes to process chemistry, temperature, material exposure, service duty, or other process condition that could impact selection.
2. Assure that the appropriately selected materials are shipped by the manufacturers and are installed correctly with all necessary repairs or replacements completed for damaged or stressed materials.
3. Assure that all necessary field linings, coatings, and paint are correctly applied for all chemical process equipment and associated plant areas.
4. Plan and verify that the processes are operated within the process design basis criteria/assumption ranges used for chemical process equipment and system material selections.
5. Plan and verify that the surface finishing systems are maintained according to design O&M requirements (including scheduled cleaning, lubrication, component changeout, etc.)

Good documentation throughout the entire process of identifying, evaluating, and selecting materials, and also throughout implementation and use for chemical process equipment and process areas, is important for assuring that the surface finishing systems are properly designed and successfully procured, installed, operated, maintained, and managed after completion of use.

Next week, watch for the final part in this series, Part 7: Material Selection for Chemical Process Equipment – Benefits. Part 7 provides perspective on the economic, operational, and other benefits of well-designed, implemented, maintained, and documented chemical process equipment with application appropriate materials.

__________________________________________________

Integrated Technologies, Inc. is an industry-leading engineering, design, and consulting solutions firm based in Burlington, VT. We offer project planning and development, full-service engineering and design, project and construction management, and services during construction to the surfacing finishing and industrial manufacturing industries. 

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If you’ve received this email, you opted in to receive the Integrated Technologies, Inc. email newsletter at some point in the past.  We only store your email address and name with the sole purpose of sending you our email newsletter on a quarterly basis.

You can change your mind at any time by clicking the unsubscribe link in the footer of this or any email you receive from us, or by contacting us at  [email protected].

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Part 5 of the seven-part series on material selection for chemical process equipment focuses on selection of paint and powder coatings for process equipment and process system/area materials. A broad range of paints and powder coatings are available to protect materials and equipment from damage, corrosion, and degradation from other environmental factors such as UV light. Deciding which paint or coating is most appropriate requires careful consideration. While generally applied at the factory under carefully controlled conditions, it is common to require field touchup or final coatings after installation is complete. This can be a key consideration in deciding what paint or coating is applied to each piece of equipment or material.

The type of paint selected can make all the difference in the expected life of the equipment; it is very important to understand the differences so that you can recognize potential problems and avoid costly mistakes.

Types of Paint

There are many types of paints but they generally fall into two categories; solvent based and water based. Most paints are comprised of a binder or resin, such as epoxy or urethane, combined with pigments for color and a liquifying agent, either water or a chemical solvent. In some cases, special additives are used to give the paint specific properties, e.g., resistance to UV light, added flexibility, or increased hardness to name a few.  Both solvent- and water-based paints can be either one- or two-part systems and have a variety of requirements for application and curing or drying. Some paints dry simply by the water or solvents evaporating out of the film, some chemically react and cure when mixed, while some require atmospheric moisture (humidity) or heat to properly cure. In all cases, manufacturer’s instructions for application and drying/curing environment should be carefully followed for best results.

Water-based paints are often preferred, when practical, as they typically contain far less VOCs. This can reduce health and environmental hazards as well as flammability of the paint fumes in the work space. This is particularly important in confined spaces. Solvent-based paints tend to be less susceptible to environmental effects on the drying cycle due to the fact that humidity directly affects water evaporation, but not necessarily solvent evaporation or catalyzed chemical reactions.

Types of Powder Coatings

Powder coating is an excellent option for finishing industrial equipment; it is highly durable and can be formulated for superior corrosion resistance. There are two main types of powder coatings – thermoplastic and thermosetting. Thermoplastic powders melt when baked to form a continuous coating that can be re-melted after cooling. Alternatively, thermosetting powders chemically react when heated to form a polymer network that is more resistant to breakdown though cannot be re-melted.  The most common coatings include epoxy, polyester, nylon, acrylics, polyurethane, and hybrids of epoxy and polyester.

Surface Preparation

The success of any paint or powder coating system hinges on proper surface preparation. There are two general categories for surface preparation – chemical and mechanical cleaning.  At a minimum, all materials will require a chemical cleaning to remove oils and other surface contaminants that would reduce coating adhesion. In addition, if mechanical cleaning is required, chemical cleaning should be performed first so that oils and other contaminants do not become embedded in the surface of the base material.

Mechanical cleaning is commonly required for metals with heavy surface scaling and corrosion products, as is usually found on most hot-rolled carbon steel products. The most common mechanical cleaning methods include media blasting, grinding, and sanding. The type of media used will depend on the scale that needs to be removed, the base material, and thickness of the part. Blasting thin sheet metal for instance can warp the metal if an aggressive media is used, especially at high pressure. In all cases, recycled media should be avoided as scale dusts can be embedded in the material surface if they become part of the blasting media. Additionally, in preparation for coatings, edges and corners typically need to be eased or radiused as paints and powder coatings have a tendency to thin out at edges which can lead to formation of cracks and chips.

Plastics that are to be painted may require a light sanding to roughen the surface in order to promote adhesion. There are chemical adhesion promoters that may be used in some cases instead or as a supplement to mechanical preparation. For any coating system, the surface preparation should be done in accordance with widely recognized industry standards, such as the joint Society for Protective Coatings (SSPC) and the National Association for Corrosion Engineers (NACE).

Pretreatment

Pretreatment generally refers to chemical processes used to prepare the cleaned base metal for the subsequent coatings. This may include acid etching, chemical (chem) film, or phosphating to name a few. The purpose of this step is usually to prevent the formation of corrosion products between cleaning and application of the coating and to promote adhesion of the coating. This is particularly important for metals, such as aluminum, that form oxide layers quickly. Pretreatment is considered essential for some coatings.

Paint Application

Industrial products are generally painted by manual or automated spray operations in multiple layers, starting with a primer coat for best adhesion to the base material. A heated cure cycle is often required before subsequent coats. Paints may also be applied by brush, roller, or even dipping. For certain products, particularly in high volume manufacturing, electrostatic spray deposition (ESD) painting can be used to significantly reduce overspray and paint waste. In all cases, parts and assemblies must be masked to avoid applying paint to surfaces not meant to be coated, such as threads and close tolerance mating surfaces.

Powder Application

Powder coatings are most commonly applied with ESD by a special gun that applies an electrostatic charge to the powder particles (attracting them to the grounded metal part) or by submerging parts in a fluidized bed of powder. Due to the requirement for baking, the option to powder coat is limited to products that can withstand elevated temperatures and can fit in the required curing oven.

Next week, watch for Part 6: Material Selection for Chemical Process Equipment – Selection & Evaluation Considerations

__________________________________________________

Integrated Technologies, Inc. is an industry-leading engineering, design, and consulting solutions firm based in Burlington, VT. We offer project planning and development, full-service engineering and design, project and construction management, and services during construction to the surfacing finishing and industrial manufacturing industries. 

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Part 4 of the seven-part series on material selection for chemical process equipment focuses on liners and coatings – excluding paint and powder coating, which will be explored independently in Part 5 – that can significantly enhance the chemical resistance and/or other properties for base process equipment and process system/area materials. A broad range of liners and coatings are available from many of the materials discussed in Parts 1, 2, and 3,  including metals, plastics, rubber and elastomers, FRP, advanced composites, and ceramics. Liners and coating systems can be factory or field-installed, depending on the process systems and project circumstances (please refer to these previous papers for material-specific acronyms used herein).  For liners and coating systems, the method and conditions of surface preparation and application/installation are critical to the overall effectiveness in achieving desired resistance to physical damage and chemical attack.  While these terms are sometimes used interchangeably, in this discussion (unless otherwise noted) liner systems are applicable to the surfaces inside of wet process equipment (e.g., tank interiors, pump and process equipment internals, etc.), and coating systems are applicable to exterior surfaces (e.g., tank and equipment exterior surfaces, process structural steel, concrete floors, etc.).

Surface Preparation

Effective surface preparation of materials is critical to render materials surfaces and profiles in the required state for control of both good adherence and thickness of coatings and for good fit and adherence of liners. Surface preparation includes a range of chemical and mechanical cleaning and surface treatments. Mechanical cleaning processes include sanding, grinding, and abrasive blasting. Additional surface preparation includes proper radiusing and deburring of sharp edges. It is important to complete chemical cleaning prior to mechanical treatments. Mechanical cleaning of oily surfaces can embed organic contaminants in material surfaces and impact coating and liner adhesion.  For liner and coating systems, the surface preparation techniques should be acceptable by industry standards, such as joint Society for Protective Coatings (SSPC) and National Association for Corrosion Engineers (NACE), for the specific base material surface and coating system or liner application.

Liner and Coating Application

Liner and coating application processes (following proper, complete, and quality-verified surface preparation) include: hand or automated spray-on application in layer or layers followed by curing (thermal or chemical); setting material sheets or pieces and anchoring with specialty fasteners and hardware; trowel-on layers followed by curing, powder coating, thermal fusion, thermoplastic molding and welding, electroless plating and electroplating, thermal spray, physical vapor (vacuum) deposition, cladding; and many other techniques and processes.

The following sections provide examples of different liner and coating materials and applications.

Plastics

A range of plastics are used for liners and coatings. For proper applications consideration, a full range of process chemistry and application-specific conditions and life-cycle requirements should be considered for each candidate plastic. Common surface finishing process examples for plastic linings and coatings include:

• Tank (and vessel) liners: Tank liners can typically be classified as flexible or rigid. Flexible liners range from lower cost “loose” liners to higher cost bonded liners. Loose liners, with welded seams providing elongation and tensile properties similar to the virgin material film, provide higher resistance to stress cracking compared to similar material bonded liners. One of the most typical flexible liners materials is PVC (e.g., Koroseal®). Other plastic liners are available, but less common than PVC, ranging up to PTFE for relatively high temperature and aggressive chemistry applications.

Steel and stainless-steel tanks can be factory-lined with plastics (e.g., PVC, CPVC, and PP) that are bonded to the surface. Higher temperature and chemical-resistant, fluoropolymer-bonded liner materials for metal tanks include PVDF, ETFE, ECTFE, FEP, PTFE, and PFA.  Metal surfaces are prepared by grit-blasting and cleaning. Fusion-welded virgin fluoropolymer films are bonded to the prepared metal surfaces with proprietary manufacturer processes typically involving saturating or impregnating a fabric (e.g. glass fabric or polyester) with an adhesive system, positioning the fabric between the metal surface and the fluoropolymer film, and activating adhesive setting while laminating the layers with pressure or other techniques to produce the fluoropolymer-bonded, rigid liner metal tank. Rubber materials can also be adhesively bonded to tanks and other process equipment (e.g., filter housings).

Considering dual-laminate, PVDF-lined FRP tanks, the FRP provides cost-effective tank strength and application-specific external surface properties, and the rigid PVDF liner provides enhanced application-specific chemical resistance. PVDF-lined FRP tanks are custom-made for applications under carefully controlled factory processes and procedures by highly qualified manufacturers, where a backing fabric is laminated onto a plastic film and the film is overlaid with FRP. Other dual-laminate, FRP tank plastic liners include PVC, CPVC, PP, FEP, PTFE, and PFA.

• Fluoropolymer-coated immersion heaters and heat exchangers: Aggressive chemistries can cause severe corrosion of heated metal surfaces. Highly chemical-resistant fluoropolymer coatings (e.g., PFA and PTFE) on base metal surfaces (e.g., stainless steel) provide much longer heater life without the use of much higher cost metals or superalloys that would not need coatings for an application. Fluoropolymer coatings also maintain purity of process solutions and reduce fouling and scaling (due to very good non-stick properties). Additional heater surface areas are required with the fluoropolymer coatings since they reduce the overall heat transfer coefficient, compared to non-fouled, non-corroded metal surfaces.  The fluoropolymer coating thickness and processes are optimized by manufacturers to minimize coating thickness while maintaining good coating adhesion and coverage for long service life.
• Plastic-lined pumps, valves, and other factory-manufactured process equipment: Considering plastic lining materials for wet process fluid surfaces, the Teflon plastics (PTFE, PFA, and FEP) provide for the combined highest temperature service (FEP has lower temperature ratings than PTFE or PFA) and excellent chemical resistance for a broad range of chemistries, while other materials, such as steel and stainless steel alloys, are used for the main process equipment structure material.

Metals

Metals can be deposited on properly prepared metal or non-metal process equipment surfaces to provide special lining or coating properties that extend the application of the base material, including enhanced chemical resistance and/or electrical conductivity. Metal deposition processes include electroless plating, electroplating, thermal spray, and various other physical and chemical deposition technologies. Example process equipment applications using metal coatings include:

• Improved chemical resistance for electrodes in very aggressive process chemistries: Platinum group metals (Ru, Rh, Pd, Os, Ir, & Pt) are used to coat suitable lower cost base metals (e.g., titanium) to provide desired long service life electrodes for surface finishing process applications with aggressive chemistries. Preparation of the base electrode metal titanium for platinum group metal coating typically includes mechanical polishing followed by electropolishing in specific solvent/acid mixtures.
• Specialty process reactor surfaces: Metals, ranging from nickel to precious metals, are used in non-proprietary and proprietary specialty process reaction vessels to provide corrosion resistance at process reaction temperatures or other desired process reactor surface metal properties.
• Adding metal layers onto plastics, ceramics, and composites: These are important applications in the surface finishing industry. One process approach for adding metal layers to non-conductive base materials is by first depositing a base layer using electroless plating (chemical etching and then metal deposition from a non-electrified process solution), followed by electroplating to build up the desired metal layer thickness to provide desired conductivity or other properties. Metal-coated plastics, ceramics, and composites have relatively minor applicability to surface finishing chemical process equipment.

Other Materials

Many of the materials discussed in Part 3 have applications in surface finishing process equipment linings and coatings, including composite materials and advanced composites, technical ceramics, and rubbers and elastomers. To meet project application needs, other liners and coating materials may also include glass, amorphous carbon, and acid-proof brick; these have some common and some limited specialized applications for surface finishing process systems and plant areas.  Some limited examples from a diverse range of other materials used for chemical process equipment and process area surfaces include:

• A range of vinyl ester epoxy or other resin coating products with application-specific solids/fill materials are commonly applied in varied multi-layer systems, typically including a base layer, one or two coats above the base layer, and a topcoat layer. Specific resin coating systems are used for different process concrete areas (e.g., 100% solids polymer blend with epoxy novolac base topping for process area floors and tank pads, or as a top-coat lining for sumps and containment areas) and for process area structural steel applications specific to process chemistry exposure conditions ranging from constant immersion to short term containment/frequent spills to intermittent spills followed by prompt washdown.
• Graphite particles blended into PFA powder are one example of a composite coating for heater and heat exchanger surfaces where the graphite provides for significantly increased thermal conductivity while maintaining the coverage integrity and chemical resistance of the PFA coating.
• Glass-lined steel tanks are manufactured where glass materials are fused to the interior steel tank wall at high temperature (e.g., 1600°F) to provide a lining for specialty high-purity and corrosion resistant applications.

Next week, watch for Part 5: Material Selection for Chemical Process Equipment – Paint & Powder Coating.

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ITI is a global consulting, engineering, and design-build firm based in Burlington, Vermont. We specialize in manufacturing processes, water and wastewater treatment, recycling, and ventilation applications for the metal and surface finishing industry.

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If you’ve received this email, you opted in to receive the Integrated Technologies, Inc. email newsletter at some point in the past.  We only store your email address and name with the sole purpose of sending you our email newsletter on a quarterly basis.

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