Caltech Engineering Services manufacture, supply Strip / Rectangular / Disc / Welded Coupons, Stressed Coupons and other range of corrosion coupons test that accurately determine the corrosion of metals in various service conditions. Strip type corrosion coupons are produced in number of sizes, shapes, and material as per customer needs. Corrosion coupons meet NACE Standard requirements and tested before shipment.
While ordering test coupons, please refer technical specifications, type of material you are testing, size of coupons, surface finish, mounting holes and locations.
Corrosion coupons are supplied in VCI Bags for excellent storage of ferrous and non- ferrous coupons. VCI bags supplied generally protect material up to 1 year under proper environment conditions.
Always ensure proper cleaning procedures as given in ASTM-G1, NACE Standards. Note service, initial weights, exposure dates, exposure time, and location for each sample. Record such information on VCI Bag provided
. Each coupon is pre-weight before shipment, Ensure once again before exposure and during Pre-Exposure.
Corrosion Coupons are highly used to monitor corrosion rates in any environment, which is critical when viewed in terms of the maintenance and repair costs associated with corrosion and material failure. Test Coupons are comparatively low cost and effective to measure loss in weight in terms of mils/year to estimate corrosion, important information regarding material life expectancy.
Accurate monitoring of corrosion rates in any environment is critical when viewed in terms of the maintenance and repair costs associated with corrosion and material failure. Test coupons provide an inexpensive means of on-line monitoring that will allow you to effectively measure the corrosivity within your system. By observing the mils-per-year corrosion rate of an exposed coupon, valuable information can be provided regarding the material's life expectancy.
Metal Samples can make coupons in any size, shape, or material you need. Coupons can be stenciled with alloy and sequence numbers for proper identification. Mill test reports, identifying element compositions of materials used, are provided on all orders. The simplest, and longest-established, method of estimating corrosion losses in plant and equipment is weight loss analysis. A weighed sample (coupon) of the metal or alloy under consideration is introduced into the process, and later removed after a reasonable time interval. The coupon is then cleaned of all corrosion product and is reweighed. The weight loss is converted to a corrosion rate (CR) or metal loss (ML), as follows:
The technique requires no complex equipment or procedures, merely an appropriately shaped coupon, a carrier for the coupon (coupon holder), and a reliable means of removing corrosion product without disruption of the metal substrate. Weight loss measurement is still the most widely used means of determining corrosion loss, despite being the oldest method currently in use.
Weight loss determination has a number of attractive features that account for its sustained popularity
The method is commonly used as a calibration standard for other means of corrosion monitoring, such as Linear Polarization and Electrical Resistance. In instances where slow response and averaged data are acceptable, weight loss monitoring is the preferred technique
- Simple - No sophisticated instrumentation is required to obtain a result.
- Direct - A direct measurement is obtained, with no theoretical assumptions or approximations.
- Versatile - It is applicable to all corrosive environments, and gives information on all forms of corrosion.
Reference should be made to NACE Recommended Practice RP-0775 and ASTM G-1 & G-4 for further detail on surface finishing and cleaning of weight-loss coupons
Our Technician and experts can provide technical assistance at the request of customers.
Use of corrosion coupon has several advantages as below:
- No corrosion coupon replacement during the evaluation
- No maintenance requirements
- No timetable to accommodate
- Can be used for all pipes at all flows
- No electrical requirements
- No flow rates to maintain or required
- No equalization period required
- No big coupon assemblies to install
- No big coupon assemblies to install
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