Life’s tough for a tank – weather attack from the outside, chemical attack from the inside. A corrosion control system has to work hard to protect tanks. Our range of abrasive blasting and industrial coating systems helps to give the coating system on your tank a “fighting chance.”
Industrial Storage & Water Tank Blast & Paint Equipment
Fuel storage requires both internal and external coatings. The tank is the most susceptible area to corrosion in a fuel storage tank. Fuel and oil are lighter than water, as a result, water separates out to the bottom of the tank. Mixed with the water at the bottom of the tank are chlorides and other salts. For steel, this mixture is a deadly combination. To help combat this extreme corrosion, risk, as a minimum, the tank floor and the bottom three feet of the wall must be coated.
It is crucial that surface preparation is completed to the highest standards in order to avoid re-work and costly tank downtime.
With BlastOne’s experience and tailored solutions, we can help to dramatically improve your production rates – from automation, to upgrading to current generation equipment, to employee training – all can help to increase productivity. We will guarantee your facility is equipped with the equipment package the provides the highest quality result at the lowest cost.
Here are a few common issues we’ve found from working with the industry:
Stricter regulation due to residential location
The days of blast cleaning and painting fixed structures without complete containment are over. Tanks located in residential areas have strict regulations that require blasting dust, millscale and paint overspray to be contained. Additionally, work hours are usually reduced due to noise pollution produced from blasting.
Both containment and work-hour limits can impact an already tight project timeline, blowing out your project budget.
Multiple access poins
Access around fuel tanks is often a challenge because of the distances involved. Typically, the hoses are run around the outside of the tank. This can result in pressure losses when blasting and also when painting.
Where a tank has two or more access points, either move your blast rig once the first half is completed or set-up a second rig. This not only improves performance, but it eliminates the need to run an extra hose to the other side of the tank.
Plan ahead! Before you start a new project, take time to plan your equipment placement. This helps to ensure a more efficient and productive project outcome.
Lack of surface testing and resulting coating failures
One of the most serious errors a corrosion control contractor can make is to fail to check a newly blasted surface for contaminants. Failure to simply check can be the cause for coating failure, resulting in rework expenditure and loss of productivity.
Maximizing coating life on fuel tank interiors is important because a fuel tank out of service is a fuel tank not producing profits for it’s owner. As these assets individually generate substantial revenue streams, every hour lost is a loss of profit.
High moisture levels
Rust forms as the result of an electrochemical action whereby electrons are transferred from iron to oxygen. The rate of corrosion is affected by water and accelerated by the presence of electrolytes. Sodium Chloride (salt) is an electrolyte. Removal of water from the reaction slows he corrosion rate.
To prevent flash rusting on the interior of a tank, the atmosphere must be as dry as possible. An effective method for drying the interior atmosphere of a tank is by using a dehumidifier. With dry air, moisture cannot condense on the tank surface; allowing the white metal blast to be held longer.
The most common types of abrasive used are GMA Garnet, Coal Slag and Copper Slag. Often large, obstruction free tank floors are blasted with shot blast machines. These use steel grit and shot. Tank walls can be shot blasted using robotically controlled machines suspended on cables. The high-quality abrasives achieve a more consistent finish, a higher quality surface cleanliness and a more consistent profile. The best abrasive achieving this is GMA Garnet. GMA garnet carefully washed, screened, and graded blend of particle sizes ensures there is enough of both large particles to remove heavy contaminants and fine particles to scour out any pitting of the surface.
COATING TYPES AND EQUIPMENT
A variety of different coatings are used to protect storage tanks. Internally, tanks are typically coated with solvent-less epoxies or high solid epoxies. These require a high-level specification class of blast, usually SP5, minimum SP10. Typical coating thicknesses are 20-30 mils, sometimes as high as 40-60 mils.
Pneumatic airless spray pumps are used in applying protective coatings to tanks. The typical set-up for these coatings is a 60:1 ratio (or larger) pump running either one or two guns with large tips. Tip range is commonly 27-31 thou. Some contractors use plural component heated sprayers for their solvent-less and high-build epoxies to minimize coating wastage, save on mixing time, and ensure on-ratio mixing.
The major advantage of having good lighting on a blasting site is the safety of personnel. Having the good lighting will also allow the blaster to achieve a better quality surface, quicker. Good visibility leads to a higher quality job, which leads to a reduction in rework. Typical type of lighting used are spotlights or helmet lighting attachments.
Always remember that a tank is a confined space. These spaces require watchers equipped with intrinsically safe radios and communication systems. Sign-in/sign-out procedures for each individual confined space are essential.
An abrasive blasting enclosure that doesn’t have adequate ventilation will quickly become filled with a dusty, hazardous haze, hindering productivity and safety.
Working in confined environments such as tanks by law requires good ventilation. Sometimes, the coating that is being removed will be hazardous, e.g., lead based. As these substances are toxic, specialized systems will be required. It is also essential for the productivity of the blasting team to maintain good visibility during the blasting process.
Good ventilation will:
Reduce the dust level inside the tank, improve the visibility and allowing the blasters to work efficiently. It is important to have the ductwork from the ventilation system positioned close to where the operators are working. This keeps the work area around them the clearest, ensuring maximum visibility.
Enhance blaster’s safety by removing hazardous dusts. Many older coatings contain lead or other harmful materials, which can cause long and short-term health complications.
Reduce clean up time after finishing blasting. By moving the dust out of the work area, it does not settle back down over the newly blasted surface, preventing recontamination.