304 Stainless Snap Rings

304 stainless snap rings are used in conjunction with boiler tube erosion shields, which is a clip that easily installs boiler tube erosion shields to the tube.

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304 Stainless Snap Rings

Stainless 1Cr25Ni20Si2 tube shields are made of 1Cr25Ni20Si2 stainless steel and can be customized to fit perfectly straight sections, curved sections and even finned and Specialty tubes.

304 stainless snap rings are used in conjunction with boiler tube erosion shields, which is a clip that easily installs boiler tube erosion shields to the tube.

304 Stainless is a low carbon (0.08% max) version of basic 18-8 also known as 302. Type 302 has 18% chromium and 8% nickel.

ASTM A213 TP304 Stainless Steel Seamless Tube is manufactured by seamless process used in high pressure environment, stainless steel TP304 grade is the most used material due to its high strength and excellent corrosion resistance.

304 stainless tube shields raw material
304 stainless tube shields raw material

Type 304 has slightly lower strength than 302 due to its lower carbon content. Type 304 finds extensive use in welding applications because the low carbon permits some exposure in the carbide precipitation range of 800°F – 1500°F without the need for post-annealing operations.

Chemical composition of 304 stainless

Grade C Mn P S Si Cr Ni N
304 0.08% max 0.02 0.00045 0.03% max 0.75% max 18 - 20% 8 - 12% 0.1% max
304L 0.03% max 0.02 0.00045 0.03% max 0.75% max 18 - 20% 8 - 12% 0.1% max
304H 0.04-0.10 0.02 0.00045 0.03% max 0.75% max 18 - 20% 8 - 12% 0.1% max

Typical specifications for 304 Plate and 304L Stainless Steel Plate are ASTM A-240, ASME SA -240 and A666.

304 stainless steel,also known as 18/8 stainless steel, European norm 1.4301, is the most common stainless steel. The steel contains both chromium (usually 18%) and nickel (usually 8%) metals as the main non-iron constituents. It is an austenite steel. It is not very electrically or thermally conductive, and is non-magnetic. It has a higher corrosion resistance than regular steel and is widely used because of the ease in which it is formed into various shapes.

Grade 304L is the low carbon version of 304. It does not require post-weld annealing and so is extensively used in heavy gauge components.

Mechanical Properties of 304 Stainless

Data Metric Imperial
Tensile Strength, Ultimate 655 MPa 95 ksi
Tensile Strength, Yield 290 MPa 42 ksi
Elongation at Break (in 2") 0.55 0.55
Rockwell Hardness B84 B84

304 Stainless Steel Plate has very good formability and can be readily welded by all common methods.

Our precision machinery and state of the art facilities enables us to produce these 304 tube shield in superior quality and precise dimensions. All these years have enhanced our capabilities and enabled us to produce all kinds of standard tube shield as well as custom snap rings as per customer’s specifications. We have numerous combinations of sizes readily available in large number of stocks and can fabricate custom sizes according to customer’s requirement.

In common with other austenitic stainless steels, 304 grade has strong work hardening characteristics. Clearly, in some cases, this can be an advantage, but generally, it is an issue to be considered carefully.

If it is likely to be an issue, discussion with the producer can be valuable as minor variations to the precise composition and process can have benefits.

Where heavy sections have to we welded, post-weld annealing may be necessary to restore corrosion resistance.

The cross-sectional shape of boiler tube erosion shields is mostly semi-circular (180 degrees), and there are also 120-160 degrees. It is mainly used on finned tubes (water-cooled walls); boiler tubes erosion shields are divided into direct wear-resistant shields, in-curve anti-wear shields, outer-curve anti-wear shields, side-curve anti-wear shields, s-curve anti-wear shields, etc. The length of the straight anti-wear shields ranges from 20mm to 3000mm, and the general length of 1000-2000mm is commonly used. The anti-wear shields with bends generally requires a processing, drawing and the following parameters should be on the drawing: outer diameter of the pipe used, bending of the pipe radius r (to the centre of the pipe), the degree of bending angle, and the length of the straight sections on both sides of the arc segment of the wear-resistant shields.

The most basic parameter of boiler tube erosion shields is the outer diameter of the tube used (that is, the inner diameter of boiler tubes erosion shields). The main specifications of the tube are: 32, 38, 42, 44.5, 48, 51, 57, 60, 63.5 , 76, 89mm, etc .; the inner diameter of the boiler tubes erosion shields is usually 1-3mm larger than the outer diameter of the tube used, depending on the actual requirements.

Alloy 304 a T-300 series stainless steel austenitic, which has a minimum of 18% chromium and 8% nickel. Type 304 has a maximum carbon of 0.07% . It is the standard “18/8 stainless” that is commonly found in pans and cooking tools. Alloy 304 is the most versatile and widely used alloy in the stainless steel family. Ideal for a wide variety of home and commercial applications, Alloy 304 exhibits excellent corrosion resistance and has a high ease of fabrication, outstanding formability. The austenitic stainless steels are also considered to be the most weldable of the high-alloy steels and can be welded by all fusion and resistance welding processes.

Specifications: UNS S30400

Snap rings for tubes erosion shields

Snap rings are used in conjunction with boiler tubes erosion shields, which is a clip that easily installs boiler tubes erosion shields to the tube.

Snap rings drawing

The snap ring and Boiler Tubes Erosion Shields are overlapped and welded, generally about 190-200 degrees Erosion Shields is a 180-degree semicircle), but also leave a welding position for easy welding and fixing. Generally, each piece of Boiler Tubes Erosion Shields needs to be equipped with 2-4 snap rings with a pitch of 200-500mm.

The anti-wear snap ring is also called clamp, buckle, tube clamp, etc.

The main role of the anti-wear tile snap ring: the role of fixing the anti-wear tile to avoid problems such as the anti-wear tile falling off during installation.

The types of common anti-wear tile rings can be divided into: U-shaped lap type snap ring, butt-type semicircular snap ring.

U-Shaped Snap Ring

The inner diameter of the U-shaped snap ring is the outer diameter of the wear-resistant tile plus the thickness of the wear-resistant tile, and the length varies from 20mm to 70mm. It will be 5mm more in semicircle. The extra part during installation will hold the wear-resistant tile and then spot weld. Compared with the butt-type semicircular snap ring, it is stronger after holding the wear-resistant tile and welding.

C-shaped snap ring

C-shaped snap ring is the most common snap ring. Mainly based on the size of anti-friction tile, the diameter and thickness are similar to the matching anti-friction tile, and the length varies from 20mm to 70mm. It is mainly connected to the wear-resistant tile by spot welding when installing the wear-resistant tile, so as to fix and prevent the wear-resistant tile from falling off.

Custom snap ring

Custom snap rings are the recommended method for tube shield attachment.

  • Style: Bull, Overlap, Wrap
  • Tube Diameter: 0.500" to 5.000" (Tube OD is shield ID), XML
  • Angle of Wrap: Maximum 240° XML
  • Gauge: 7 to 24 XML
  • Material: 304 SS, 316 SS, 309 SS, 310 SS, 430 SS, Inconel

All products are purchased to proprietary customized specifications as well as normal industry standards with supporting documentation.


Material

Different types of stainless steel are selected according to the specific conditions of different working conditions.

Common materials are: TP321 (Cr18Ni9Ti), TP309S (Cr23Ni13), 1Cr20Ni14Si2, TP310S (Cr25Ni20), 1Cr25Ni20Si2, and some low temperature areas (such as low temperature superheater, low temperature reheater) are made of 1Cr13, 1Cr6Si2Mo and other materials.

The boiler was originally designed to be accurate. Different materials have different temperature resistance and mechanical strength. 1Cr13, 1Cr6Si2Mo generally has a temperature resistance of 600 ℃ or less.

Stainless erosion shields

Main material of tube erosion shields

Material(Grade) Temperature resistance Yield strength Tensile strength Elongation HB HRB HV
1Cr18Ni9Ti 925 ℃ ≥205MPa ≥520MPa ≥40% ≤187 ≤90 ≤200
Cr23Ni13 1095 ℃ ≥205MPa ≥520MPa ≥40% ≤187 ≤90 ≤200
1Cr20Ni14Si2 1095 ℃ --- ≥590MPa ≥40% --- --- ---
Cr25Ni20 1150 ℃ ≥205MPa ≥520MPa ≥40% ≤187 ≤90 ≤200
1Cr25Ni20Si2 1150 ℃ --- ≥540MPa ≥35% --- --- ---

We can also supply boiler tubes erosion shields of other materials.


Installation

Generally, boiler tubes erosion shields are also installed to prevent further wear of the tubes and cause serious consequences such as boiler explosion.

The main role is to protect the heating surface of the boiler pipes, reduce pipeline wear, and increase the heating surface of the pipes.

Install erosion shield with snap ring

The snap ring is a short section that is installed on the pipe in conjunction with the wear-resistant tile. Generally, it is welded to the wear-resistant tile by lap welding, that is, to cover the wear-resistant tile slightly, so it is larger than the wear-resistant tile. The opening arc is around 190-200 degrees, the welding position needs to be set aside to facilitate welding and fixing. The width of the snap ring must not be less than 20mm.

The installation requirements of anti-friction tiles of different shapes are slightly different. Basically, each anti-friction tile is installed with not less than 2-4 snap rings. The snap ring and the anti-friction tile are welded together to prevent expansion due to heat. The tiles fall off, and the joints are required to be fully welded.


Packing

Generally, boiler tubes erosion shields are also installed to prevent further wear of the tubes and cause serious consequences such as boiler explosion.

The main role is to protect the heating surface of the boiler pipes, reduce pipeline wear, and increase the heating surface of the pipes.

F&Q

Our understanding of and commitment to the steam and power generation business enables us to solve your boiler tube erosion or corrosion problems efficiently. Our technical staff can quickly recommend the proper material type and configuration to meet your needs…and can quote your outage delivery requirements on a month basis.

Do you accept a special order?

A: Yes, we do. We can manufacture all kinds of chemical equipments according to your technical drawings(Before you givethem to us, will sign the contract and confidentiality agreement with you. You don’t need to worry about that.)

Can you make a design for us?

A: Yes, we can. What we supply is not only product, but also solution and design. And if you make the product in our factory,the design will be free. If not, design fees will be charged accordingly.

Q: Do you provide after-sales service?

A: Yes, we do. This product is guaranteed up to one year from purchase unless manmade damage. If there is anything wrongwith product itself quality problem,we will change or repair it at our charge.If not, we will provide aftersales service at your charge.

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