Name: Corrosion Coupons EMT-CI
Availability: InStock

Description

Corrosion coupons are a simple yet effective tool for providing a quantitative estimation of corrosion rates occurring in an operating system.

Corrosion Coupon EMT-CI

Name	Corrosion Coupons EMT-CI assess Fitting For Pipeline Testing
Material	Stainless Steel 304、Stainless Steel 316、DSS F51、Carbon Steel A105N、Inconel 625


Operating Temperature	-20±120
Feature	Firstly, Easy to Operating
	Secondly, High Accuracy Long Life
	At last, High Efficiency, Low cost
Payment	TT/LC
Advantage	Firstly, they are lightweight and flexible.
	Secondly, Nice Injection efficiency.
	At last, Accurate location tracking.

Coupon Insulation

Caproco standard Corrosion Coupons EMT-CI come furnished complete with insulation made from Delrin, which has a temperature rating of 200″F (93″C).

Insulation for higher temperature requirements is available and should be specified when required.

So the higher temperature insulation materials are:

Teflon – 500″F (260″C) Rulon – 550″F (288″C) Ceramic – 1472″F (800″C)

So if you want to know more about Corrosion Coupons EMT-CI, please contact our professionals to answer them for you.

Influencing Factors of Subsea Pipeline Corrosion

Seawater corrosion is a phenomenon in which metals are corroded in a seawater environment and fail to be damaged. Seawater is also rich in natural electrolytes, almost all chemical elements on earth are contained in seawater. And the composition is very complex. In addition to containing a large number of salts, seawater also contains dissolved oxygen, marine organisms and spoiled organic matter. All of these create favorable conditions for corrosion to occur. In addition, the temperature, flow velocity, and pH value of seawater have great influence on seawater corrosion.

Salt content

Firstly, one of the distinguishing features of seawater from other corrosive environments is the high salt content. In the world’s oceans, the composition and salinity of water are relatively constant, while the salinity of inland seas varies greatly due to different regional conditions. The salt content in the water directly affects the conductivity and oxygen content of the water, so it will inevitably affect the corrosion. As the oxygen content in the water increases, the conductivity of the water increases and the oxygen content decreases, so there will be a maximum corrosion rate at a certain oxygen content, and the salt content of seawater is just close to the maximum corrosion rate. Corresponding salt content.

Dissolved oxygen

Secondly, dissolved oxygen in seawater is an important factor in seawater corrosion. Because the corrosion of most metals in seawater is controlled by oxygen depolarization. Then the surface of seawater is always in contact with the atmosphere. And the contact area is very large. Because the seawater is constantly stirred by waves and has violent natural convection. Therefore, the oxygen content in seawater is usually high.

Temperature

And then seawater temperature varies with latitude, season, and seawater depth. The closer to the equator (that is, the smaller the latitude), the higher the temperature of the seawater, and the greater the metal corrosion rate. However, the solubility of oxygen in seawater decreases when the temperature increases and the solubility of oxygen decrease by about 20% for every 10e increase in temperature, which can reduce the corrosion rate of metals. In addition, temperature changes also have an impact on the biological activity of seawater and calcareous scale deposits. Due to seasonal changes in temperature, iron, copper and their various alloys corrode faster in hot seasons.

The pH of seawater is between 7.2 and 8.6, which is close to neutral. As the depth of seawater increases, the pH value gradually decreases. The pH of seawater changes slightly due to photosynthesis. During the day, plants consume CO2, which affects pH. At the sea surface, CO2 in seawater is exchanged with CO2 in the atmosphere, thereby changing the CO2 content. The pH value of seawater is far less affected by the oxygen content as the corrosion rate. The pH value in seawater mainly affects the deposition of the calcareous scale, thus affecting the corrosiveness of seawater. Although the pH value of seawater decreases with the increase in seawater depth. Bur the surface seawater is highly corrosive to steel due to the high oxygen content of the surface seawater.

Flow rate

The corrosion of many metals has a great relationship with the seawater flow rate, especially common metals such as iron and copper have a critical flow rate. When the flow rate exceeds this flow rate, the metal corrosion is significantly accelerated, which promotes the diffusion of dissolved oxygen to the metal surface. Therefore, when the flow rate increases, the depolarization effect of oxygen is strengthened, and the corrosion rate of metal is accelerated. But passive metals are more resistant to corrosion in high-velocity seawater. For steel piles immersed in seawater, the corrosion rate of each part is different. Near the waterline, especially at 0.3~1.0m above the water surface, due to the impact of the waves, the oxygen supply is particularly sufficient and the corrosion products are continuously taken away, so the corrosion rate here is 3~4 times higher than that of the fully immersed part.

Marine life

At last, the physiological action of microorganisms will produce ammonia, carbon dioxide, hydrogen sulfide, etc. Which can accelerate corrosion. In the seabed mud area, the corrosion rate is generally the smallest in various environments due to the lack of oxygen and high resistivity. However, for the ooze area with pollutants and a large amount of organic matter deposition, due to the existence of microorganisms and the reproduction of sulfate-reducing bacteria, the amount of corrosion can also reach 2-3 times that of seawater.