Steelmaking Hoses and Expansion Joints

Steelmaking Hoses and Expansion Joints

Heat in steel mills places particular demands on process equipment. Few materials can handle the temperatures which often climb to 1000°F and beyond. As temperatures increase, maximum allowable working pressures decrease, and higher pressures ratings may be required to offset the reduction.

As in many industrial applications, corrosion can be a concern. Saturated steam is one common, though perhaps unexpected, culprit as the composition of water used varies widely. Higher-nickel alloys can be used to prolong service life in such scenarios.

With these criteria in mind, Penflex designs and manufactures braided metal hose and expansion joints for a wide range of steel mill applications.

Flexible Metal Hoses

Steel mills often rely on the 300 series austenitic stainless steels to support their operations. Unlike hoses made from other materials which melt or catch fire, 316L and 321 hoses retain their physical properties at high temperatures, maintaining pressure and leak tightness in critical applications. If slag splash is likely or there is a need to protect handlers from burns, fire sleeve wraps can be added steelmaking hoses.

In addition to offering a wide range of hoses in standard alloys, Penflex also specializes in hoses made using nickel alloys, like Inconel 625 and Hastelloy C-276, for applications where corrosion is a concern.

Our range of pressure ratings ensure that whether an application is high pressure or one subject to temperature adjustments, we can meet the requirements.

Steelmaking Hoses and Expansion Joints for Steel Mills

Caster Cutoff Torches

Cutoff torches, suspended above the continuous casters, rely on flexible and heat-resistant hoses to deliver the oxygen and fuel gas necessary for cutting semi-solidified steel into desired lengths.

Penflex lightweight P3 Series is our most flexible hose and the ideal solution for this application. With its thin wall construction and high corrugation count, the P3 requires little force to bend, ensuring easier installation in tight spaces. Compressed pitch options are also available for increased flexibility.

High Temperature Lubrication Lines

Well-oiled machines not only keep production on schedule, but also resist damage through wear and are less susceptible to corrosion.

Beyond its flexibility, P3 Series pressure ratings make it a suitable option for lubrication lines, and hydraulic lines as well. Where needed, Penflex 800, 900, and 1400 Series hoses can accommodate higher pressure applications, as well as applications where pressure rating reductions due to increased temperatures render more commonly used hoses inadequate.

Oxygen Lance Hoses

Clean and durable oxygen lance hoses also play an important role in steelmaking. Delivering oxygen to a Basic Oxygen Furnace (BOF) allows temperatures to climb high enough to complete the conversion of molten pig iron into steel.

There are various options when it comes to lance hose design. One of the biggest decisions to make revolves around what material to use for the inner hose, whether to opt for metal or rubber. Complete rubber hose assemblies used for oxygen lancing are generally more expensive than a metal hose assembly and, given life span ends of being the same, one wonders whether the increased price justifies an arguable marginal increase in flexibility.

Penflex metallic lance hoses are designed with a heavy wall construction well suited to the constant handling—and frequent mishandling—these products see once in service. In response to cleanliness requirements in place to ensure proper functioning, we have developed a cleaning specification specifically for Penflex lance hoses.

Water Cooling Lines

Steelmakers use water to cool steel, and the cooling rate impacts physical properties of the finished product. As such, water cooling hoses are an important part of hot rolling, casting and quenching processes. Beyond cooling, water is also used it to descale, wash, and condition. P3 Series is a common choice in these applications as well.

Steel Mills - Water Cooling Lines on Continuous Castors

Metal Bellows and Expansion Joints

Expansion joints accommodate movement and absorb vibration in piping systems and, in doing so, they protect adjacent piping and equipment from damage. Penflex designs and manufactures a wide range of metal bellows and expansion joints for steel mills that play in important role in the functioning of key equipment such as blast furnaces.

Key Features of Penflex Expansion Joints

Penflex currently manufactures expansion joints ranging in size from 2-1/2” ID to 120” ID made using either a single, two-ply or multi-ply construction. The full complement of end fittings and accessories is available.

Bellows are manufactured from the following materials with other materials are available upon request.

  • 300 Series Stainless: 321, 304L, 316L, 347H, 310SS
  • Inconel Alloys: 600, 625, 718
  • Incoloy 800H
  • Monel 400
  • Hastelloy: C-22, C-276, X
  • Titanium: Grades 1 and 2
  • AL 6XN
  • Duplex 2205

Certain alloys, like 800H, Nickel 200, Titanium Grades 1 and 2 and Duplex 2205, are used in extremely hot or highly corrosive applications. While heat is often the main concern in steel mill applications, corrosion can also be a primary cause for concern in certain applications, such as those involving coke oven or furnace gases.

Universal Expansion Joint

Blast System Furnace Expansion Joints

Blast furnaces use chemical reactions between hot air and an iron ore-coke-limestone mix to produce molten slag and molten iron. The latter is then heated further with various other inputs to make steel.

Expansion joints are used within piping in and out of the furnaces to help accommodate thermal expansion and contraction. Depending on proximity to the furnace, and ambient temperatures, the components may be made using a higher-nickel alloy, like Inconel 625, which is better suited for extreme temperature environments.

Coke Gas Lines & Ovens Expansion Joints

Coke ovens are similar in structure and technology to blast furnaces, used to turn coal into a more efficient energy source: coke. Aside from coke, coke oven gas is a byproduct of the process. It can contain chemicals like ammonia, tar, sulfur, naphthalene, benzol, and most notably carbon monoxide, meaning parts designed for coke applications will likely need to keep corrosion resistance in mind.

Combustion Lines Expansion Joints

Combustible gases produced from coke ovens, blast furnaces, and basic oxygen furnaces are repurposed at different stages of the steelmaking process and expansion joints are often used to help accommodate movements in the piping system as these byproducts are moved within the mill.

Gas Cleaning System Expansion Joints

Gas cleaning systems in steel mills clean exhaust gases, reducing air pollution. To compensate for vibrations and movements caused by thermal expansion and contraction, metal expansion joints are required. This protects surrounding piping and equipment from damage.

Similar to the gas cleaning system, reverse air fans, also called the baghouse, control emissions of pollutants from the blast furnace specifically.

Water Cooler Ducts Expansion Joints

Expansion Joints for water cooler ducts are designed for low pressure and low spring rates with high flexibility. These components are desired to damp vibration.

Steel mills rely on a range of metal hoses and expansion joints for successful operation and Penflex Sales Engineers are always available to help define application requirements for your next project, replacement, or repair. In addition to engineering and design support, we offer resources to support proper installation and maintenance for longer life in service.

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