What is PREN value for pitting corrosion?

Despite its inherent resistance to corrosion, stainless steel tubing installed in a marine environment suffers from different types of corrosion throughout its expected lifetime. Such corrosion can lead to fugitive emissions, lost product, and potential risks. Offshore platform owners and operators can reduce corrosion risks at the outset by specifying more robust tubing materials that offer better corrosion resistance. Later, they must remain vigilant in their inspections of chemical injection, hydraulic, and impulse lines, as well as process instrumentation and sensing equipment, to ensure corrosion isn’t threatening the integrity of the installed tubing and impacting safety. Localized corrosion can be … Continue reading What is PREN value for pitting corrosion?

What is Shear Stress?

Why are shear stress equations necessary? This article looks at some examples of shear stress equations: average shear stress, beam shear. What are the basics of shear stress? Whenever two materials rub against or slide over each other, there is shear. While normal stress results from the force applied perpendicular to the surface of a material, shear stress occurs when force is applied parallel to the surface of the material. A common example include the cutting of paper with scissors. Shear stress differs across materials and cross-sections, and is measured using a set of formulas called the shear stress equations. … Continue reading What is Shear Stress?

What is Holiday Test ?

Holiday Test – Overview;  A holiday test here refers to defects in coating or lining, which are Pinhole, Void, Crack, Thin Spot or Contaminant.  Holiday Test is a method for checking these defects by providing electricity through the defects in Coating/lining to Workpiece. If any area has a defect, spark or short circuit will occur. Holiday Test will be divided into two(2) main methods. According to the thickness of Coating/lining by Low Voltage or “Wet Sponge” It applies to Coat thickness less than 500 microns of High Voltage or “Spark” is used to Coating thickness greater than 500 microns. Example of understanding the methods: … Continue reading What is Holiday Test ?

Pipe support shoe (sliding type) – inspection

Pipe Supports Inspection – Pipe Shoe off Support;  When checking piping, be sure to check the position of Pipe Shoes to see if they are still in the right position or if they fall out of support like below: Pipe Supports Inspection – Fix Pipe Shoes off Support;  In the event that the pipe shoe is dropped from the support, it can be resolved by expanding the support structure to support the thermal expansion. Continue reading Pipe support shoe (sliding type) – inspection