to evaluate the corrosion rates across the diameter. The common type of holders used are: Fixed coupon holder System depressurization is required during insertion and removal It is used in systems that have frequent shutdowns or systems that can be isolated easily Simple to install Can be made from a variety of materials. How should the coupons be oriented and positioned? These can be generic carbon steel or may be selected to match the material used for a specific purpose; for example, X65 pipeline steel or weld consumables. Link to this page: a coupon /a Mentioned in? They can also be used to estimate the effectiveness of the mitigation program in place or evaluate the suitability of a specific material for a specific system. Depending on the operating conditions, number and type of coupons, configuration and system entry method, the coupon holder is selected. Corrosion coupons should be located where corrosion is expected. This has two advantages: The coupon will more accurately present the flow in the vessel For pipelines, this will enable the pipeline to be pigged Orientation with product flow is not required Special purpose coupons Scale coupons Provide the deposition rate (coupon must be made. As such, an indication of a corrosion event may only be obtained significantly after the event may have occurred.
If you would like to further understand how our corrosion management team can support your corrosion assessment and/or management requirements, please visit our contact us page. If it is required to verify whether the corrosion rate was uniform or varying over a certain time, then multiple corrosion coupons could be installed at the same location and retrieved at different times. The worst pitting corrosion rate is assessed using the depth of the deepest pit over a period of time. Also, using appropriate geometric designs, a wide variety of corrosive environments may be studied. Corrosion coupons orientation should be consistent in order to assess and compare different data sets.