Lining and Special Coatings Flashcards
What is a ‘lining’?
The term lining is used to describe a coating that is normally in immersion service. They are designed to protect the surface they are applied to and the product inside.
Standard terms for reinforced plastics are:
- Fiber Reinforced Lining (FRL)
- Glass Reinforced Plastic (GRP)
- Fiberglass Reinforced Plastic (FRP)
Common resins used in linings are:
- Polyester
- Epoxy
- Vinlester
What are reinforced coatings?
Reinforced coatings are stronger, more resistant to movement, abrasion, and impact than non-reinforced coatings
What is NACE No. 10, SSPC PA 6?
Fiberglass Reinforced Plastic (FRP) Linings Applied to the Bottoms of Carbon Steel Storage Tanks
What is NACE No. 11, SSPC PA 8?
Thin Film Organic Linings Applied in New Carbon Steel Process Vessels
What is SP0288?
Inspection of Linings on Steel and Concrete
What is SP0304?
Design, Installation, and Operation of Thermoplastic Liners for Oilfield Pipelines
What is SP0178?
Design, Fabrication, and Surface Finish Practices for Tanks and Vessels to be Lined for Immersion Service
What is SP0295?
Application of a Coating System to Interior Surfaces of New and Used Rail Tank Cars
What is SP0386-2007?
Application of a Coating System to Interior Surfaces of Covered Steel Hopper Railcars in Plastic Food and Chemical Service
What is SP0592-2006?
Application of a Coating System to Interior Surfaces of New and Used Rail Cars in Concentrated (90 to98%) Sulfuric Acid Service
Surface Preparation, Application, and Inspection of Linings
What standard to use for design, preparation of welds, edges, and corners
SP0178
Surface Preparation, Application, and Inspection of Linings
New surfaces may require what cleaning standard?
ISO Sa 3 or NACE No. 1/SSPS-SP5, White Metal Blast Cleaning
Surface Preparation, Application, and Inspection of Linings
Maintenance work may require what cleaning standard?
ISO Sa 2 1/2 or NACE No. 2/SSPS-SP10, Near White Metal Blast Cleaning
Specialized coatings serve specific limited markets and include but are not limited to:
- Antifouling paint
- Fireproof coatings
- Fluoropolymer coatings
- Thermosetting polymers
- Underwater coatings
- Powder coatings
Antifouling paints are used to minimize roughness on the hull of a ship by reducing the attachment of marine life.
True or false?
True.
The use of toxins in most Antifouling paints are regulated by these organizations:
- Environmental Protection Agency (EPA)
- International Maritime Organization (IMO)
- Other country or local regulatory agencies
What are the main types of antifouling coatings?
- Ablative
- Self-smoothing
- Foul release
What is ablative AF coating?
Binder slowly dissolves in seawater, constantly presenting a fresh layer of copper on the surface
What is self-smoothing AF coating?
Similar to ablative; rate is controlled, surface becomes smoother
What is foul release AF coating?
Do not have a biocide, “non-stick” surface
What are some inspection concerns with antifouling coatings?
- Film thickness of each coat is very important
- Oversray on top coat (salt and pepper finish). Surface roughness
- Over coating times. AF does not adhere well to cured epoxy
What is the most commonly used test for industrial and marine fireproofing material?
U.L. 1709 Rapid Rise Fire Tests of Protection Material for Structural Steel
What are the types of fireproofing coatings?
- Cementitious
- Intumescent
What is cementitious fireproof coating?
Made of lightweight cement and can be applied several inches thick
What is intumescent fireproof coating?
A substance that swells or bubbles up as a result of heat exposure, thus increasing in volume, and decreasing in density
What applications are thermosetting polymers principally used in?
- Mining
- Offshore
- Ocean marine
How are thermosetting polymers applied?
Material is melted and hot spray applied
What is the purpose of thermosetting polymers?
Purpose is to encapsulate the item
What are the two board curing categories of powder coatings?
- Thermoplastic
- Thermosetting
What is thermoplastic curing in powder coating?
Materials that soften when heated and return to their original hardness when cooled
What is thermosetting curing in powder coating?
Materials that harden when heated and retain their hardness when cooled
What are the stages when heat is applied powder coatings?
- Flow
- Wetting
- Gel
- Curing
Powder coatings applied to a heat source pass through four distinct stages:
- Flow
- Wetting
- Gel
- Curing
How long does it generally take to complete this process?
The complete process generally takes less than three minutes
What are some types of thermoplastic materials?
- Polyvinyl chloride (PVC)
- Polypropylene (PP)
- Kynar (PVDF)
- Halar (ECTFE)
- Polyethylene (PE)
- Teflon (FEP & PTFE)
What are some types of thermosetting resins?
- Epoxy
- Urethane
- Polyester
- Acrylic
What are the application methods for powder coatings?
- Electrostatic spray
- Fluidized Bed, dip method
- Flame spray
- Roto-Lining
What is the most common and efficient method for spray applying powder coatings
Electrostatic spray
Describe the fluidized bed application method.
A finely divided stream of air is passed through a power, a solid in gas dispersion is form, which behaves like a liquid
Describe the flame spray application method.
Thermoplastic powder particles are blown under low air pressure through a high-temperature, open-flame torch
Describe the roto-lining application method
- Pre-weighed amount of powder into a hollow mold.
- Mold and powder are heated in oven
- Powder melts on contact with metal
- When cooled, the powder has formed a protective coating
What are some special application equipment for powder coatings?
- Plural-component spray systems
- Electrostatic spray
- Centrifugal spray for pipe internals
- Flow and flood coating
What is a plural-component spray system?
Plural-component is the automatic metering and mixing of plural-component materials
How quickly can plural-component spraying can be done?
Can be done with coatings having a pot life of 3 seconds to a few minutes
What are the two basic plural-component spray equipment types?
- Fixed ratio machines
- Adjustable ratio machines
How are the components of the coating blended in a plural-component spray setup?
Components of the coating are blended in a manifold and mixed in an inline static mixer or mixed at the spray gun tip
What are hot spray systems used for?
Used for material that requires higher temperatures to make them sprayable
What are the advantages of hot spray systems?
- Accurate mixing of materials without human element
- Ability to spray very thick solvent free materials without thinner
- Ability to spray materials with very short pot life
What are the disadvantages of hot spray systems?
- Cost is higher
- More education for mechanic
- High voltage electricity is needed
- Applicators job more difficult
What are the three main technologies for charging the coating in electrostatic spray?
- Direct direct to coating
- Tribo charges gun
- Post-atomization atomization spins on wheel
What are the advantages of electrostatic spray?
- Fairly complete coverage of off shapes
- Uses liquid or powder coatings
- Efficient transfer of liquid coatings
- Very uniform film build
- Better film build (coverage) of edges
What are the disadvantages of electrostatic spray?
- Coating formulation is critical
- Not all coatings are suitable
- Can only be used on metal or suitable conductive substrate
- Usually only a single coat application
- High voltage safety issues (shock)
- Equipment costs
Describe centrifugal spray application for pipe internals.
- Uses a rapidly spinning disc, brush, or other device to atomize the coating
- May be used with or without electrostatic charge
- Widely used to line pipe in specialized shop operations
Describe flow and flood application.
- Consists of pumping material on top of an item and allowing it to cover the item
- Coating has to be designed for this type of application
- Excellent method to coat items that have fins
Describe electrostatic spray application.
- Can be used for many liquid-applied coatings
- Normally only seen in shop application
- Transfer efficiency between 75% to over 90% depending on process
Thermosetting materials are materials which _______?
A. Harden when heated and retain their hardness when cooled
B. Harden when heated and soften when cooled
C. Soften when heated and return to their original hardness when cooled
D. Soften when heated and remain soft when cooled
A. Harden when heated and retain their hardness when cooled
The feed mechanisms for a plural component spray unit are where the ___________.
A. Components are blended in a manifold and mixed in a static mixer
B. Components are mixed in a chopper gun
C. Components are mixed at the spray gun tip
D. Components are mixed in a pressure pot
A. Components are blended in a manifold and mixed in a static mixer
C. Components are mixed at the spray gun tip
Which of the following are common methods for the electrostatic application of liquid or powder coatings?
A. Post atomization charging
B. Direct charging
C. Tribo charging
D. Electro-osmosis charging
A. Post atomization charging
B. Direct charging
C. Tribo charging
You are the inspector on a project where the application is required on a parge surface consisting of 200 radiators, connect and stacked 1” apart. The configuration will not allow a dip process, so the most logical application would be _________.
A. Conventional spray
B. Flood & flow coating
C. HVLP spray
D. Plural component spray
B. Flood & flow coating
The basic function of passive fireproofing is ___________.
A. Providing temporary protection to living or work space
B. Stopping the fire from spreading to other locations
C. Expanding in volume to put out the fire
D. Corrosion prevention
A. Providing temporary protection to living or work space
Bio-fouling of the submerged portion of ships is minimized through the application of _________.
A. Aliphatic polyurethane
B. Ablative coatings
C. Self-smoothing coatings
D. Conventional epoxy
B. Ablative coatings
C. Self-smoothing coatings
Which of the following components are contained in powder coatings?
A. Pigments
B. Solvents
C. Resin/binder
D. Flow control additives
A. Pigments
C. Resin/binder
D. Flow control additives
You are the inspector on a project that requires coating the internal of 4 inch diameter piping. The owner asks for an example of an application process for coating the internals. What would be the best choice?
A. Dipping the pipe
B. Centrifugal spray
C. Flood and flow coating
D. HVLP
B. Centrifugal spray
The benefits of electrostatic spray application over conventional spray are ________.
A. Produces somewhat thicker coatings on edges
B. Works on all substrates
C. Transfer efficiency improved
D. Little risk of shock hazard
C. Transfer efficiency improved
Coating material that soften when heated and return to their original hardness when cooled are known as _____.
A. Thermosetting materials
B. Transformational materials
C. Transitional materials
D. Thermoplastic materials
D. Thermoplastic materials