Stainless Steel 309S Fittings, UNS S30908 Fittings Supplier & Exporter

GENERAL PROPERTIES

Alloys 309 and 309S are austenitic chromium-nickel stainless steels that are often used for higher temperature applications. Due to their high chromium and nickel content, Alloys 309 and 309S are highly corrosion resistant, have outstanding resistance to oxidation, and excellent heat resistance while providing good strength at room and elevated temperatures. The only significant difference between 309 and 309S is the carbon content. Alloy 309S has a much less carbon composition which minimizes carbide precipitation and improves weldability.

APPLICATIONS

Alloys 309 and 309S are used exclusively for their high temperature oxidation resistance, excellent high temperature strength, along with their resistance to creep deformation and environmental attack. Some examples include, but are not limited to:

• Heating elements
• Aircraft and jet engine parts
• Heat exchangers
• Carburizing annealing products
• Sulfite liquor handling equipment
• Kiln liners
• Boiler baffles
• Refinery and chemical processing equipment
• Auto exhaust parts

CORROSION RESISTANCE

• Provide excellent corrosion resistance
• More resistant to marine atmospheres than Alloy 304
• Often used at higher temperatures to take advantage of their oxidation resistance
• Have high resistance to sulfite liquors
• Generally considered heat resistant alloys
• Destructive scaling temperature is approximately 2000oF
• Good scaling resistance with regard to continuous and intermittent services

HIGH TEMPERATURECORROSION

Alloy 309 resists high temperature corrosion in most in-service conditions. Operating temperatures are as follows:

• Oxidizing conditions (max. sulfur content–2 g/m3)
  • 1922°F (1050°C) continuous service
  • 2012°F (1100°C) peak temperature
• Oxidizing conditions (max. sulfur greater than 2 g/m3)
  • 1742°F (950°C) maximum temperature
• Low oxygen atmosphere (max. sulfur content–2 g/m3)
  • 1832°F (1000°C) maximum temperature
• Nitriding or carburizing atmospheres
  • 1562–1742°F (850–950°C) maximum

The alloy does not perform as well as Alloy 600 (UNS N06600) or Alloy 800 (UNS N08800) in reducing, nitriding or carburizing atmospheres, but it does outperform most heat resistant stainless steels in these conditions.

FABRICATION

• Can be roll formed, stamped, and drawn readily
• In process annealing is often required to reduce hardness and increase ductility

HEAT RESISTANCE

• Cannot be hardened through heat treatment because the consist solely of austenite at room temperature
• Higher tensile and yield strengths that can be obtained through cold working and not followed by full annealing are not stable at the higher temperatures where these alloys are used
• Creep properties can be negatively affected by the use of cold worked material at these higher temperatures

WELDING CHARACTERISTICS

• The austenitic class of stainless steels is generally considered to be weldable
• Generally considered to have weldability equivalent to the most common alloys of the austenitic class 304 and 304L
• Special consideration is needed to compensate for a higher coefficient of thermal expansion to avoid warping and distortion

CHEMICAL PROPERTIES:

MECHANICAL PROPERTIES:

PHYSICAL PROPERTIES:

Fittings and Flanges for Stainless Steel Pipe
Stainless steel piping systems can be joined by butt welding and, in the heavier 40S and 80S schedules, with threaded connections.

BUTT WELDING STAINLESS STEEL PIPE FITTINGS

Harsh steel stocks butt welding fittings in the following configuration.

• Elbows 45 degree and 90 degree - long radius and short radius.
• Return bends 180 - long radius and short radius.
• educers - concentric and eccentric.
• Tees - equal and reducing.
• Caps.
• Stub ends - Type B.

Advantages of stainless steel butt Weld fitting to the pipe are to keep pipes permanently leak proof. The continuous structure helps strength between pipes and fittings. It reduces pressure and also minimises the action of corrosion and erosion. Butt welding fittings can be supplied in either seamless or welded construction and are covered by specifications ASTM A403M and ASTM A815M for Duplex grades.

STAINLESS STEEL SCREWED AND SOCKET WELD FITTINGs

Stainless steel piping systems can be connected using stainless steel screwed fittings - BSP threaded ("150lb") low pressure stainless steel fittings and NPT class 3000 high pressure stainless fittings in Grade 316. Socket weld fittings are used in high pressure piping systems and available in grade 316L to suit schedule 80S wall thickness piping.

MANUFACTURING SPECIFICATIONS:

• ASTM A182M (3000lb NPT and socket weld).
• ANSI B16.3 (BSP dimensions)
• ISO 4144 (BSP dimensions)

STAINLESS STEELS FITTINGS AND FLANGES:

A flange is a ring of steel (forged, cut from plate, or rolled) designed to connect sections of pipe, or to join pipe to a pressure vessel, valve, pump or other integral flanged assembly. Flanges are joined to each other by bolts, and to the piping system by welding or threading (or loose when stub ends are used). Forged stainless steel flanges are designed to the following common pressure ratings, stainless steel flanges are exported by Harsh Steel in Classes 150, 300, 600, 900, 1500 and 2500. Standard sealing face is Raised Face (RF).
The basic types of flanges are:

• Stainless steel slip-on flange
• Stainless steel socket weld flange
• Stainless steel blind flange
• Stainless steel lap joint flange
• Stainless steel weld neck flange
• Stainless steel threaded flange
• Stainless steel orifice Flange

Manufacturing specification: ASTM A182M
Plate stainless steel flanges are cut and machined from plate - Table 'D', Table 'E', etc.
Manufacturing specification: AS2129.
Types and applications of Stainless steel and Nickel alloy flanges

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