How to Blast and Paint Pipe – A Complete Guide
Whether your in Pennsylvania working on Natural Gas pipelines in the Marcellus shale region or in Louisiana working on oil well lines properly painting and blasting pipe is critical to ensure you properly protect the pipe from elements. Typically clients who choose to work with you on oil and gas pipe will want to ensure that you have selected a proper coating, applied it to the proper mill thickness, and prepared the pipe for the coating properly. This guide will cover how to paint & blast pipe to ensure your coating delivers the performance it was specified to.
Critical Factor 1 in Painting & Blasting Pipe – Surface Preparation
Most of the time when you are painting & blasting pipe their will be a standard for surface preparation. Common blast profile preparation standards include NACE or SSPC standards.To ensure your pipe is properly blasted you want to pick a blast media that will provide the proper blast profile. The grit size and type of media along with the pressure you use will determine how much of an anchor profile you leave. With blast pressure you should start low and slowly increase pressure checking the profile against a visual gauge and once you are close to the desired profile you can then move on to a greater precision measurement option. This guide further covers measurement of blast profile. Just remember preparing the surface is critical as it will be one of two primary determinants of how well your coating performs. Also often times it can be a good idea to have a replica tape that will be pressed on the pipe surface and capture the blast profile placed on the pipe. This allows you to have a record showcasing the blast profile has been properly completed.
Critical Factor 2 in Painting & Blasting Pipe – Coating Selection
The paint system you use on the pipe will directly determine the longevity and protection of the pipe. The paint should be specified by the company you will be doing work for. If it is specified or not it is always a good idea to work with a certified coatings inspector, someone who has a NACE level 1 or higher certification. This type of certification shows that they have studied protective coating systems and ensures that they will help you with proper coating selection. When you select a coating you should follow the technical data sheets which are provided by each paint manufacturer. These sheets specify the paint equipment to use, the environmental conditions that need to be followed, and more.
Critical Factor 3 in Painting & Blasting Pipe – Coating Application
After the coating has been chosen, the pipe properly blasted and tested that the profile is correct, next you have applying the coating. The proper way to apply each coating will differ slightly but in general, for a majority of pipeline coatings, you will typically be using a thick industrial or marine type paint product. These types of coatings are typically applied with a paint pressure pot and conventional spray gun or airless paint sprayer. If the paint has a short time before it hardens, you may have to consider a plural component sprayer. Depending on the paint and if it tends to separate while painting you may need an agitator in your paint pressure pot. You should apply the paint and check occasionally to ensure you are applying the proper amount of paint to the surface, the amount of coating you should apply should be listed in wet mils which is what you will pay attention to while coating pipe. To check the wet mils you can use a wet mil gauge which we cover how to use one here.
What about painting and blasting the inside of pipe?
A common challenge of blasting & coating a pipe that we hear often is how do you prepare the inside of the pipe. There is a manual way and a more automated way that can make blasting and painting the inside of pipe easier. To blast the inside of a pipe you can use an angled blast nozzle. These nozzles have an outlet out the side that angle the blast media out. This allows you to blast inside a pipe but the challenge is that you still have to control the blast hose. This limits how far in you can reach to blast. As an alternative that is a bit more automated and can blast long pipe lengths easier, Clemco offers a tool called the hollow blast which can be pulled through a blast pipe and blast it properly.
For painting, the interior of pipe common options include a spray gun extension which allows you to reach into a pipe and can be built to the size you need. They are available for airless or air spray guns. You can also use a tool like the Clemco Orbiter that is pulled through a pipe and automatically paints it.
Final thoughts
Properly blasting and painting pipe is critical to ensure your coating system performs like the coating manufacturer states it will. Proper preparation, coating selection, and application will help guarantee you get the results you should out of painting & blasting pipe. If you need help with proper equipment for your painting or blasting contact us today.