Corrosion Coupon Manufacturer

Description

EMT is a corrosion coupon manufacturer. Corrosion Coupons are used to monitor the corrosion rates of the sample (coupon) in the pipe or container. By observing the mils-per-year corrosion rate of an exposed coupon, valuable information can be provided regarding the material’s life expectancy. EMT Corrosion Coupons are specially made for corrosion and erosion studies and are manufactured to the most demanding standards. And EMT Corrosion Monitoring is also divided into flange connection and thread connection according to the connection. You can check your pipeline by it.

1. Overview

Sea pipes have many advantages. It is almost unaffected by the environment and can be conveyed continuously. And then it has the advantages of high oil transportation efficiency and strong transportation capacity. However, the pipelines are laid on the seabed, and some pipelines are still buried to a certain depth. This brings difficulties to the monitoring and maintenance of pipeline corrosion. Subsea pipeline transportation of media is very complex. Therefore, we can classify from the perspective of conveying medium. Such as dry gas pipelines, wet gas pipelines, reinjection water pipelines, crude oil pipelines, and mixed pipelines. Then the acid, alkali, salt, acid gas, sand, and bacteria in the conveying medium will cause internal corrosion to the pipeline.

Although the pipeline has left a corrosion allowance in the design stage. In the production process, workers generally take anti-corrosion methods such as dehydration, desalination, deacidification, and chemical injection. However, it is affected by the combined effect of material defects, construction damage, improper use of chemicals, and medium corrosion. Tubes still face a severe risk of internal corrosion failure. Monitoring of internal corrosion of subsea pipelines. It can detect potential failure risks in time. So this is of great significance to avoid economic losses and environmental pollution caused by pipeline leakage.

2. Principles and characteristics of monitoring technology

2.1 Inductance probe method

This method monitors corrosion within a pipeline by continuously monitoring the inductance and inductance signals of a test piece of the same material as the pipe that is exposed to a corrosive environment. When the thickness of the test piece changes. We apply a constant alternating current to the test coil. This creates a magnetic field around the coil. Then the coil inductance is very sensitive to the thickness change of the metal test piece. When the metal test piece has minimal thinning due to corrosion. The inductance of the test coil will also be affected. By measuring the inductance change through the coil, the corrosion thinning amount of the metal test piece of the inductance probe can be calculated. And then the corrosion rate can be calculated.

The advantages of the inductive probe monitoring method are numerous. For example, it has many applications and can be used in any corrosive environment. So it has high monitoring accuracy, high sensitivity and short response time. Its response time in a corrosive environment of 0.0254 mm/a is only 1 h. Such as stable performance, good sealing, high-pressure resistance, strong corrosion resistance. It can be also used continuously for 2 a in a corrosive environment of 5 mpy. Then based on the above advantages, inductive probes are often used to evaluate the actual effect of anti-corrosion measures directly. Inductive probe monitoring can also be used to adjust process parameters in industrial pipeline corrosion control.

2.2 Coupon method

A coupon of known size and mass is placed in a corrosive environment inside the pipe. The material of the coupon is also the same as that of the pipe. After exposure for a certain period of time, the coupons are removed. After degreasing, rust removal, and drying, the mass is weighed. The corrosion degree and type of the pipeline were judged according to the quality and morphology changes before and after the test piece. In the corrosion monitoring of the subsea pipeline, the coupons are usually set with 3 layers. Then they are placed in the water layer, oil layer, and gas layer respectively. This also reflects the corrosiveness of water, oil, and gas, respectively. When there is sediment corrosion in the pipeline, horizontally installed disc coupons can be used. Then simulate the sedimentary corrosion of the pipe wall at 6 o’clock in the sea pipe.

When the pipeline flow rate is high and erosion may exist, vertical strips are usually selected. Simulate erosion-corrosion at high wall shear stress locations. In addition to visual observation and quality analysis, the tested coupons often need to be supplemented by pitting depth analysis, corrosion product analysis, and scaling product analysis. The data obtained by the coupon method can comprehensively reflect the influence of corrosion factors. And its reaction information is rich, it is the most intuitive and reliable monitoring method. However, the test cycle required by the coupon method is longer (generally, the coupon can be replaced once every 3 months). And the reflected corrosion information is the comprehensive result of the test period. This does not reflect transient corrosion information.

2.3 Resistance probe method

The resistance probe technology is to expose the metal wire of the same material and a specific length as the resistance probe to the corrosive environment in the pipeline. When the wire corrodes, the current in the constant voltage loop drops. It is assumed that uniform corrosion occurs on the wire surface. Then, by calculating the resistance change, the reduction in the cross-sectional area of ​​the wire can be calculated. This results in a uniform corrosion rate. Changes in temperature can also cause changes in wire resistance. In a corrosive environment with large temperature changes, the resistance error caused by temperature changes has a large influence and cannot be ignored. In this corrosive environment, resistance probes are also often used in conjunction with temperature sensors. This compensates for temperature errors.

Because the resistance probe technology does not have strict requirements for the application environment. So it is suitable for corrosion monitoring in almost all corrosive environments. And then the device components are simple to manufacture and have low cost. This is a long-established and widely used corrosion monitoring technique.

But resistance probe technology also has limitations.

①Firstly, insensitive to corrosion rate monitoring. Because the temperature in the corrosive environment always changes in a small range. This causes the loop resistance to also fluctuate (commonly referred to as the temperature effect). Usually, this requires the amount of wire corrosion to build up to a certain extent. The resulting increase in loop resistance is considered corrosion by the data processing system.
②Secondly, regardless of local corrosion or uniform corrosion, the circuit resistance will increase. Therefore, we cannot judge whether local corrosion occurs by the change of resistance;
③ At last, unable to quantitatively monitor local corrosion.

3. Research status and development trend of monitoring technology

Because there are many types of subsea pipeline transportation that need to focus on corrosion monitoring from the perspective of media. This includes oil-gas-water pipelines, oil-water pipelines, and wet natural gas pipelines. They are all multi-phase mixed losses. The development time of oil and gas fields is gradually extended. Pipeline throughput, water cut, and acid gas are always changing. The internal corrosion of sea pipes is also affected by microbial corrosion, inorganic scaling in produced water, wax precipitation of crude oil, sand and gravel deposition, deposition and adhesion of corrosion products and pipeline elevation. The causes of corrosion are complex.

Therefore, there is a sharp contradiction between the reliability and detection accuracy of the existing internal corrosion monitoring technology and the needs of customers. Most corrosion monitoring techniques are still very crude for localized corrosion monitoring. Therefore, it is difficult for workers to reliably predict the local corrosion rate and location. And then this is the problem that customers need to solve the most. The development direction of corrosion monitoring is integrating and applying non-destructive testing technology and corrosion online monitoring technology. This combines the advantages of multiple detection techniques. It can also comprehensively evaluate the corrosion state of sea pipes.

corrosion coupon

Because the marine atmosphere is humid and salty. The design and application environment of the electrical components of the active corrosion monitoring and detection device is mainly in the land oil field. So it is difficult to work continuously in harsh environments and failures occur frequently. Therefore, the marine environment applicability of the corrosion monitoring device in the subsea pipeline needs to be improved urgently.

Because of management upgrades and policy orientation. Digital and unmanned offshore platforms are the future development direction. Therefore, the internal corrosion monitoring technology should also meet the market demand and integrate communication technology. It transmits the output data from the platform to land analysis in real-time. This enables digital remote management of internal corrosion.

4. Summary

The corrosive environment in the subsea pipeline is complex and diverse. In addition, there is also an interactive effect on the corrosion types in the submarine pipeline. Therefore, its corrosion rate is generally higher than that of land oil and gas pipelines. Once the sea pipe failure accident occurs. This will not only cause an unplanned shutdown of equipment and facilities, and stagnation of production, resulting in huge economic losses. And it can have serious social and environmental impacts. Compared with onshore oil and gas pipelines, the subsea pipeline has a long span, and the underwater construction cost is expensive. Therefore, it needs a reasonable corrosion monitoring system to correctly grasp the corrosion state of sea pipelines and ensure the safe operation of oil and gas pipelines.

Why Choose US as the Corrosion Coupon Manufacturer?

1. Firstly, samples will be offered to attest to the quality and our services
2. And then the fastest delivery time.
3. At last, 24 hours,7 days online.

We cooperate with many express companies. So that could ensure the fastest delivery time and lowest shipping cost.

Packaging&Delivery

We use PLYWOOD CASE as packaging, it has the following advantages:

1. Lightweight, clear lines, insulation, high strength, not easy to deform;

2.No fumigation is also required.