Installing Quality Internal Tank Linings: A Perspective David Cushman West Virginia Paint LLC General Manager NACE Certified Coating Inspector #1591 Copyright 2013

External Paint or Internal Paint What is the difference? Immersion service calls for better surface preparation Confined space issues Surface access Uninspectable for many years And of course….

Dust Abrasive blasting is a dusty process!

If you don’t manage your dust…. You can wind up with a coating like this.

How do you measure clean? Cleanliness is very important Surface preparation needs to be a minimum SP-10 near white metal or better yet SP-5 white metal blasting Test for contaminants in the air stream Test for contaminants in the abrasive

Test for chloride contamination Can test using various methods What are the sources of the contaminant? Hydro test water Product sludge Tracking on feet

Surface preparation is a visual standard that needs to be met with tough working conditions

SP-10 near white vs. SP-5 white metal

Recycled media Advantages Less disposal Less dust “Cleaner” working conditions Disadvantages Does not access to all surfaces to be prepared May be challenging to get equipment into the tank Difficult to ensure “sharp, angular profile” Recycle process does not remove any contaminants, just classifies by particle size

Dehumidification

Two cardinal rules Rule 1: What goes in, must come out! =

Rule 2: What goes up, must come down!

Cleaning the residual dust and grit Where to look?

Blowing and vacuuming Blowing is often used to remove dust from the surface OR Combination of Methods OSHA regulations regarding blowing with compressed air Vacuuming is used to cleaning the surface Vacuuming has hazards from static

Dancing?

Once the surface is clean … Applying the proper coating at the proper thickness Applying the proper coating to the proper surfaces

Selecting the Coating MIL –PRF-4556(F) Types of Coating- Generic Film Build Where to apply?

Epoxies- Generic Amine Phenolic Novolac Other high performance products

Which surfaces get coated? How high do you coat? Do you coat the lower three feet? Do you coat the entire wetted surface? Do you coat the roof underside and structure? Internal piping and equipment? Where is corrosion occurring?

Inaccessible areas A tank built to API 650 with a lap welded roof and a rafter structure has plenty of areas that cannot be coated Only a best effort can be made

Film Thicknesses Specifications define film thickness It is possible that there is excessive pitting and there is not enough coating film

So what substrate condition are you starting with?

If you apply a thin film too thick…

If you apply a thick film too thin

This coating is just right!

Holiday testing and cure Holiday testing is done to ensure that the film has no voids This is the subject of an entire presention, beyond the scope of this discussion

Curing Proper curing is essential to a good job. If you rush the cure, you might be throwing away the whole job.

Importance of floating suction

Coating may be performing multiple functions Protecting the steel substrate from corrosion Preserving product quality

ULSD and MIC- A connection? Recent developments showing accelerated corrosion for ULSD service Uncoated tank bottoms needing replacement after only 10 years New phenomenon- never had issues with conventional distillate products (high sulfur) MIC- “microbially induced corrosion”

Good operations procedures are essential to keep the product clean! IN ADDITION TO INTERNAL COATING: Floating suction Filtration and filter maintenance Removal of residual dust and grit following coating Regular dewatering and sludge removal

Any questions?