As an industrial boiler system manufacturer, you know corrosion causes most system failures. After all, a boiler system is constantly exposed to the corrosive effects of water and gases. Not only is this a performance issue, but a safety one as well. Premature system failures damage your good reputation.
Boiler system deaerators are at particularly high risk. Failures most frequently occur at the welds and in adjacent areas. This makes sense since the deaerator is exposed to the excess oxygen and gases in the feedwater prior to removing it to maximize boiler system operation.
So, as a manufacturer, how can you build a system to slow corrosion and maximize performance?
One way is to source your deaerators from a fabricator specializing in manufacturing steel tanks exposed to corrosive elements and harsh environments.
Pressure Vessel Manufacturers Bring Steel Tank Excellence
Pressure vessel manufacturers, particularly those constructing vessels to ASME standards, deal with corrosion issues every day. They have literally built a business choosing materials and proper welding processes for durable, long-lasting steel tanks.
Rexarc, a pressure vessel fabricator with generations of steel tank excellence, is particularly poised to provide industrial boiler manufacturers with quality deaerators that can extend system life.
In addition to building ASME-coded and noncoded tanks for a variety of industries, Rexarc works with leading boiler and deaerator manufacturers as a supplier. With nearly a century of expertise in building high-performance custom steel tanks, Rexarc knows the materials and processes to use in constructing spray, tray and vacuum deaerators complementary to your systems. They have the experience, skills and knowledge to help enhance your boiler system performance.
Materials Knowledge
The primary material of a boiler system is steel, specifically various grades of stainless steel. Where water and steel mix, there is oxidation. Remember that oxidation is the reaction between excess oxygen in the air or water and the ferrous components of steel. It really cannot be avoided when the two mix, but adjusting the materials increases corrosion resistance and slows its effects.
Choosing the right stainless steel grade can make a difference in the oxidation and corrosion of the deaerator:
- 304: Also known as 18/8 steel, grade 304 resists corrosion and endures a wide range of working environments, making it extremely popular.
- 304L: The low-carbon grade of 304, this option helps minimize chromium carbide precipitation during welding . It is less susceptible to intergranular corrosion and is suited for severe corrosive conditions.
- 316: Grade 316 can resist crevice corrosion, pitting in chloride environments, and can withstand high temperatures. It is a molybdenum-bearing grade that exhibits better corrosion-resistant properties than 304.
- 316L: This grade is excellent in high-temperature environments, offering excellent tensile and rupture strength. It withstands high pressures and offers exceptional resistance in acidic and hard-water environments. This is a low-carbon grade with molybdenum, resistant to pitting and corrosion. Grade 316L offers high formability and deformation resistance.
- 317: This non-magnetic stainless steel grade with an increased concentration of nickel, molybdenum, and chromium. The molybdenum concentration improves resistance to pitting from chlorides.
- 317L: A low-carbon grade of 317, it offers excellent corrosion resistance over other grades. This variety does not produce precipitate during welding.
Welding Materials and Processes Aid Corrosion Prevention, Too
Having a variety of materials available for deaerator fabrication means having a variety of welding processes available is necessary. Pairing the optimal welding process with the best-performing materials will yield the best corrosion resistance and long-term performance of deaerators.
Welding options include:
- Submerged Metal Arc Welding (SAW): A common process, this method is where an arc is formed between the workpiece and commonly fed electrode. This method requires no shielding gas and the arc is submerged below the flux blanket making it invisible during the process.
- Shielded Metal Arc Welding (SMAW): This weld is created using a flux-covered consumable electrode. SMAW has gained popularity owing to its simplicity and results.
- Gas Metal Arc Welding (GMAW/MIG): Sometimes referred to as metal active gas (MAG) welding or metal inert gas (MIG) welding, the electric arc is formed between the workpiece and the consumable MIG wire electrode. The arc heats the workpiece, melting it and causing it to join. The method also utilizes a shielding gas fed through the welding gun.
- Flux Cored Arc Welding (FCAW): This is an automatic or semi-automatic welding process, which utilizes a continuously fed consumable tubular electrode with flux and a constant power supply to conduct welding. This method ensures excellent welding speed.
- Gas Tungsten Arc Gas Welding (GTAW/TIG): This is an arc welding process, which uses the arc between the weld pool and a non-consumable tungsten electrode, along with shielding gas.
Each welding process also has its best uses and performs best with certain alloys over others.
GMAW/MIG welding is typically used for thinner sheet metals. It is the weld type of choice for stainless steel and aluminum.
Arc welding (SAW and SMAW) can be used on a variety of metals and allows. Most commonly, it is used for carbon steel, stainless steel, cast iron, ductile iron, and high- and low-alloy steel. This technique also can be used on aluminum, and nickel and copper, and their alloys.
GTAW/TIG welding is used on non-ferrous metals such as aluminum, magnesium, and copper alloys. It also is used on stainless steel.
Pressure vessel manufacturers with an extensive record of performance know the best combination of materials and processes for you and your customers. They can be a powerful partner in delivering the quality and performance your customers expect.
Opt for a Specialized Manufacturing Partner
You know the industrial boiler market. You know how to make amazing boilers. You also know that corrosion is your enemy, yet your device puts all the ingredients in close quarters and asks them to play well with each other.
There is little you can do about the outcome. However, you can choose to optimize your parts and components so that they perform better and longer than your competitors. You can give your customers better return on investment for their boiler purchase.
By choosing a specialized manufacturer with deep knowledge and skills in all the elements of deaerator manufacturing, you set yourself apart from the others. Rexarc has the skills and experience to help elevate your boiler performance.