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.
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.
The snap ring and boiler tube 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 tube 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 a 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.
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
Application
Alloy 304 Stainless Steel is used in a wide variety of home and commercial applications, including:
- Kitchen benches, sinks, troughs, equipment, and appliances
- Chemical containers, including for transport
- Food processing equipment, particularly in beer brewing, milk processing, and wine making
- Heat exchangers
- Architectural trim and molding
- Woven or welded screens for mining, quarrying & water filtration
- Automotive and aerospace structural use
- Nuts, bolts, screws, and other fasteners in the marine environment
- Construction material in large buildings
- Dyeing industry
Standards
- ASTM/ASME: UNS S30400 / S30403
- EURONORM: 1.4301 / 1.4303
- AFNOR: Z5 CN 18.09 / Z2 CN 18.10
- DIN: X5 CrNi 18 10 / X2 CrNi 19 11
Install erosion shields 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.
