Nickel Alloy Stem UNS S32760 Super Duplex F55 1.4501 Valve Regulation Forging
Nickel Alloy Valve Stem is an important component of the valve, used for transmission. It connects to the actuator or handwheel at the top and directly drives the valve core to move or rotate at the bottom, thereby achieving the function of opening, closing, or regulating the valve.
Valve Stem Seal:
Most compression packings use asbestos fibers as the base material due to its performance properties. It is essentially unaffected by most media, temperatures, and time, and is a good thermal conductor.
- The drawback of asbestos is its poor lubricity, so it is necessary to add lubricants that do not impair the performance of asbestos, such as graphite powder and mica powder. Since this mixture still has some permeability, it is also necessary to add liquid lubricants.
- Polytetrafluoroethylene (PTFE) has the smallest shrinkage rate and lowest water absorption, as well as a low coefficient of friction. It has high corrosion resistance to most corrosive media. PTFE packing can operate at temperatures ranging from -150 to 260°C. Within this temperature range, it is a high-performance, multi-purpose valve stem packing.
- Flexible graphite has the property of high-temperature resistance and also has a low coefficient of friction and resistance to most corrosive media. It can operate at temperatures up to 600°C in the packing area, so valves in high-temperature applications such as power plants and petrochemical industries use flexible graphite packing.
UNS S32760 / 1.4501 / F55:
Material to UNS S32760 (and the other specifications listed below) is described as a super duplex stainless steel with a microstructure of 50:50 austenite and ferrite. The steel combines high mechanical strength (typically up to 600 MPa yield strength) and good ductility with outstanding corrosion resistance to marine environments and a wide, diverse range of oil & gas production environments. The alloy is supplied with a PREN (Pitting Resistance Equivalent) at >= 40.0 which guarantees high
resistance to pitting corrosion. In addition, the steel offers high resistance to crevice corrosion and stress corrosion cracking. Ambient and sub-zero (down to minus 50 °C) notch ductility is good. These attributes mean that this super duplex steel can be used successfully as an alternative to 300 series stainless steel (such as type 316), standard 22% Cr duplex steel and precipitation hardening stainless steels. Where appropriate the alloy can be considered in lieu of more costly Grade 5 titanium or
nickel based alloys.
Availability:
Bar, forgings, sheet, plate, pipe, tube, closed die forgings, flanges and welding consumables.
Related material specifications:
- UNS S32760 in various ASTM product form specifications
- EN 10088-3 1.4501 (Grade X2CrNiMoCuWN25-7-4)
- NORSOK MDS D51 to D55, D57 & D58
- ASTM A182 F55
- NACE MR01-75 (latest revision) / ISO 15156
Machinability / Welding:
The machining and welding of this grade of super austenitic stainless steel presents no particular problems. Guidance notes are available upon request.
Typical Applications:
Pumps, valves, chokes, Xmas trees, pipework / flanges, bolting, connectors & manifolds. In oil and gas industry,equipment in defence, chemical and marine industries.
Chemical Composition:
| Element | C | Mn | Si | S | P | Cr | Ni | Mo | Cu | N |
| Minimum(%) | - | - | - | - | - | 24 | 6 | 3 | 0.5 | 0.20 |
| Max(%) | 0.03 | 1 | 1 | 0.015 | 0.035 | 26 | 8 | 4 | 1 | 0.30 |
Reference Standards:
| General | - Norsok M-650 Ed.4 qualified manufacturers
- PED 2014/68/EU Annex I section 4.3
- AD2000 W0 (W2/W10)
- NACE MR0175/ ISO 15156-3 and NACE MR0103/ISO 17945
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| Plate, sheet and coil | -
ASTM A240, EN 10028-7, EN 10088-2, EN 10088-4, Norsok M-630 MDS D55 |
| Bar and forging | -
ASTM A276, ASTM A479, ASTM A182, EN 10088-3, Norsok M-630 MDS D54/D57 |
| Other products | |
Applications:
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Process industry components in nitric acid, dioxide, polypropylene & PVC production, caustic evaporators |
- Equipment handling organic & fatty acids
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- Marine industry and shipbuilding propellers, shafts, rudders, shaft seals, pumps, bolts, fasteners, valves, instrumentation
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- Oil & Gas industry pumps, valves, pipe, vessels, wellhead equipment, subsea equipment
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- Pollution control systems, fans and pumps, wet scrubbers, incinerators, flue gas desulphurisation (FGD)
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- Pulp & paper industry components such as black liquor heater tubes, digester blow valves, rotary feed valves, I.D.fans, brownstock washers, precipitators, bleaching components
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- Food Industry applications including sugar cane centrifuges, corn and vegetable processing plant
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- Agrochemicals production such as fertilisers (based on wet phosphoric acid)
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- Sewage treatment, seawater cooling, desalination plants
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Processing Flow Chart:
