Pipe cleaning has become heavily scrutinized and the internal and external cleaning is being scrutinized extensively. It is important to understand that pipe is delivered all over the world and is subject to varying environmental conditions. At Pepco we deal with pipe systems that range from water treatment, oil and gas, heavy construction, as well as varying industries such as mining.
Pipe systems are designed to transport commodities throughout a confined space while being under varying levels of pressure. Metals have natural properties that protect against corrosion and exposure to failure but without proper cleaning methods pipe lifespan can be dramatically reduced. On typical systems corrosion is the biggest culprit, but also there can be other defects present.
3 Methods of Cleaning:
1. Mechanical‐Pepco uses mechanical means to clean pipe, grinders, buffing wheels, as well as flapper pads to remove the rust and any defects.
2. Sandblasting‐ Sandblasting can be utilized on internal / external pipe at Pepco, this is a thorough method that allows the rust and any protective coating to be removed and the surface is then prepared to be coated.
3. Chemical‐ The common term for this type of cleaning is “Pickling/Passivation”. Typically, this is used for stainless steel pipe but can also be used in varying carbon steel applications. Passivation is the treatment of the surface of stainless steels, often with acid solutions (or pastes), to remove contaminants and promote the formation of the passive film on a freshly created surface (e.g. through grinding, machining or mechanical damage). Pickling is the removal of any high temperature scale and any adjacent low chromium layer of metal from the surface of stainless steel by chemical means. Where the steel has been heated by welding, heat treatments or other means, to the point where a coloured oxide layer can be seen, there is a chromium depleted layer on the surface of the steel underneath the oxide layer.