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Cleaning and passivation are an integral part of system performance and maintenance.

Cleaning and passivation remove surface contamination (metal oxides, inclusions, and bio-contamination), improve the formation of the passive (inert) layer or zone and increase the chromium/iron ratio producing a corrosion resistant surface.   

Properly passivated stainless steel contains a chromium oxide film which serves as a barrier at the surface that resists the corrosion process rendering it corrosion resistant.  However, when the surface is manipulated by metal finishing, welding, grinding, and external contamination etc., then passivation is required to restore or enhance the chromium oxide film on the stainless steel surface.

Benefits of passivation:

1. Reduce corrosion vulnerability.
2. Reduce product contamination potential.
3. Extend system maintenance intervals.
4. Decrease equipment downtime.
5. Meet cGMP surface quality requirements (if applicable).

Passivation is the chemical treatment process by which the electrochemical condition of passivity is obtained on the surface of metal alloys. Passivity as it relates to austenitic stainless steel is the state in which chemical reactivity is minimized under special environmental conditions, such that the metal exhibits a very low corrosion rate.

Stainless steel surfaces are rendered passive by the formation of a surface film that is a "barrier" to corrosion. This "barrier" establishes a very slow, controlled equilibrium of anion and cation diffusion across it. This passive layer consists primarily of chromium oxides, hydroxides and iron compounds which form on the outermost surface of the metal phase. Through diffusion, the passive layer constantly "fixes" or re-passivates itself under minimum corrosion conditions. Initial passive layer establishment is achieved through chemical treatments which remove foreign inclusions and more reactive metal ions. This treatment enhances the effective concentration of chromium, nickel and molybdenum (in the case of 316-grade stainless steel) at the surface of the metal phase. Through an unknown mechanism, these three metals together affect the creation of a more homogenous chromium oxide/ iron oxide passive layer. The uniformity and stability of the film will vary depending upon the method of treatment. Passive layer thickness and stability is critical to system longevity and product purity.

Passivation efficacy has always been paramount to us. All of our chemistry formulations meet, or exceed, industry standards for cleaning and passivation and their efficacy has been confirmed by Electron Spectroscopy Chemical Analysis and AUGER Electron Spectroscopy.     
 

Vapor degreasing is a simple yet highly effective cleaning process. Unlike aqueous degreasers which require parts to be immersed in a solution and require rinse and dry, vapor degreasing is a process by which parts are lowered into a high temperature solvent vapor zone where the condensation of vapors into liquid on the surface of the hardware flushes oils and other contaminants from the surface. The condensed pure solvent aggressively removes contaminates.
 

The vapor degreaser has a heat source that raises liquid solvent to its boiling point. When the solvent boils, it produces hot, thick vapors that rise to a set vapor line. At this point, the vapors are condensed on cold circumferential condenser coils, and they do not rise any higher. Because the solvent vapors are heavier than air, they push the air above the vapor line. Parts at ambient temperature are then introduced into the solvent vapor, and the solvent vapor condenses on the surface of the parts. The liquid solvent produced as a result of this condensation is in essence freshly distilled, and it dissolves the greases and oils on the part and flushes them away as it drips from the part back into the solvent reservoir. As parts are cleaned, more vapors are produced in the boiling sump to replace those that were condensed.

"Pigs" were originally developed and utilized to remove the debris or material build-up which obstructed or restricted flow through a pipeline. Pipeline "pigging" is loosely defined as the propelling of a projectile (the pig) through a pipeline to push the contents out. Pigging is utilized to flush out debris and build-up, scrape and clean the interior pipe walls, and "batch" various products through a piping system. It is performed during new construction and pipeline repair or modification. Pigging is also essential in areas of de-commissioning, abandonment and subsequent removal of pipelines. Typically the industry uses four basic types of pigs: polyurethane foam pigs, mandrel or mechanical pigs, solid cast urethane pigs, and high tech "smart pigs". The most common of them is the versatile "poly pig" which is thrust through the pipeline by hydraulic or pneumatic pressure to clean the interior walls, remove debris and flush liquids from the pipeline. Whatever the reason for flow interruption or restriction, pigging is the preferred method for improving the flow and restoring the pipeline to its required capacities. Pigging is cost efficient, very effective and environmentally friendly. More importantly, it is a viable and economical alternative to pipeline replacement.
 

In every production process or transfer system, there is the possibility of product loss or contamination. There are variations in the direction and elevation of piping systems that trap costly product in portions of these pipes. Furthermore, cross-contamination can occur when a different product is introduced in a subsequent run. Therefore, a good product recovery system is valuable to the bottom line. Flow-Line Services understands plants with typical piping systems are faced with loss of product, waste surcharges, diluted product and cross-contamination. Subsequently, Flow-Line Services also provides fabrication, consultation and sales of "Product Recovery Systems " and the special pigs utilized in these systems. The use of these pigs following a transfer of product, ensures maximum retrieval of usable raw or blended materials that otherwise would remain in the pipeline, and be lost or contaminated. Maximum product recovery reduces the volume of water, solvents or other material used in line cleaning and/or sanitation. Related disposal costs and cleaning time between batches are also minimized.