Pipe fittings are an indispensable part of piping works. Now that the world has seen a boom in stainless steel usage from houses to heavy industries, stainless steel fitting manufacturers produce pipe fittings of the same alloy in hefty numbers because of its versatility and popularity.
What makes SS piping extensions so popular?
Stainless steel is composed of the same metal additions to Iron like nickel, carbon and manganese to some extent. What is done differently in SS is the addition of 18-20% chromium which gives it the resistance to corrosion. To begin with, a balance of workability, rust proofing and strength makes it the most commonly used alloy among stainless steel fittings suppliers.
- Apart from that, such a blend of sturdiness and the anti-corrosive property offers a reduction in the wall thickness of fittings and hence its weight is reduced significantly.
- It has ecological benefits as well. Stainless steel can be used as a food-grade alloy and can be used in the drinking water supply. It is reusable and can be processed again.
- This alloy has greater economical benefit since it remains intact in terms of its properties even after long-term usage and ergo, retains its value for ages. What’s more, it possesses negligible maintenance cost.
Types of stainless-steel fittings available
Almost every sort of SS extension is available depending on plumbing circumstances. The most usual ones that are frequently asked for by clients are crosses, couplings, elbows, tees, locknuts, valves, unions, plugs, locknuts, caps and bushings.
Types of SS pipes based on the process of fusion
Both seamless and welded kinds of pipes are accessible in stainless steel.
Seamless pipes, as the name suggests, lack seam or weld spots. Spotless surfaces without visible joints between fittings make them suitable for a large range of heavy-duty applications like engineering, gas and oil industries.
Welded pipes are made out by welding the fittings. They are cost-effective and have more or less similar advantages to that seamless ones. Welded piping works are further classified into Electric fusion welding, Electric resistance welding, high-frequency welding and submerged arc welding.
Let us have a look at the process used to manufacture it.
- Electric resistance and fusion-welded fittings involve a rolling procedure. In these methods, the metal stripe is rolled across its length.
- In HFW, current at high frequency is passed to weld two parts together.
- The SAW method of welding makes use of external filler material for fusing metal.
What are the outstanding properties of SS alloy?
- Oxide layer generation
Microthin coating of chromium oxides makes it corrosion-proof. It can generate such coating on surfaces that have become vulnerable to rust because of this very same reason.
- Low-temperature resistance
One of the grades of SS called austenitic ss has a substantial amount of strength even at freezing temperatures when tensility of other grade alloys like ferritic and martensitic drop in significant proportions. This is to say that it possesses tremendous cryogenic resistance and retains its robustness in extreme environments.
- Hot strength
SS alloys consisting of a high fraction of chromium have the ability to withstand peak levels of heat. Ferritic grades of the alloy have one such characteristic that makes it ideal for use in elevated temperatures.
- Work hardening
It is a property of stainless steel where it becomes durable after undergoing plastic deformation through cold working. This makes it fit for heavy-duty purposes.
Ductility is a feature that indicates an alloy’s ability to elongate before it deforms. Austenitic steel has high ductility which means it can withstand severe situations.
- High tensile strength
Austenitic grade holds the capacity to withstand higher tension in comparison with normal steel alloy. Martensitic steel has the highest measure of tensile strength followed by duplex steel.
- Stress corrosion cracking
Cracking which appears suddenly due to failure of any part or deformation is SCC. Few prime reasons for the appearance of such cracks could be an accumulation of residual stress meaning exposure to sudden transformation in the phase of alloy or sudden temperature changes.
- Ease of machining
One of the many reasons for its wide range of utility is the simplicity of fabrication and good formability.
Different grades of pipe fittings
Most frequently bought ones are 304/304L, 316, 310/310S, and 317/317L
It is an austenitic, nonmagnetic SS alloy which is called 18/8 SS as well because of its composition containing 18% chromium and 8% nickel. Widely purchased by the food industry since it withstands the corrosiveness of substances in milk, meat, fruits, acidic and alcoholic beverages.
Stainless steel pipe companies produce 304L so as to have minimal carbon precipitation but mechanical properties are slightly inferior to that of 304.
The molybdenum content of this class of steel contributes to its anti-corrosive properties. It is especially unyielding to crevice corrosion as well as has pitting resistance. That is why it has especially found its applications in cement manufacturers plus pharmaceutical sectors.
These have moderate carbon proportions and are intended to be used for extremely high temperatures as in furnacing, boilers, kilns and several other such components. It can bear temperatures up to 2102 Fahrenheit.
Due to its robustness, it can be used within extremely low or high temperatures along with acute pressure conditions. It has found its applications in acid dye factories, sulfur compound production, nitrates and bleaching materials.