904L Stainless Steel Pipe
904L is one of the strongest stainless grades for corrosion resistance, written as 1.4539 or X1NiCrMoCu25-20-5 under EN and as UNS S08904 under the UNS system. It carries a very high level of nickel, molybdenum and…
What This Product Is For
904L is one of the strongest stainless grades for corrosion resistance, written as 1.4539 or X1NiCrMoCu25-20-5 under EN and as UNS S08904 under the UNS system. It carries a very high level of nickel, molybdenum and chromium, and the combination is what makes it resistant to attack in acidic environments such as sulphuric, phosphoric and acetic acid. Pipe is supplied solution annealed in outside diameters from 10 mm to 1067 mm.
Key Benefits
- Holds up in sulphuric, phosphoric and acetic acid where 316L and 317L corrode
- Solution annealed delivery condition, so the pipe arrives with its corrosion resistance restored
- Outside diameter range from 10 mm to 1067 mm covers instrument tubing through to large process headers
- Three polished grit levels plus mill pickled surface
- Length up to 13000 mm reduces the number of circumferential welds on long runs
Who It Is For
- Chemical plant piping engineers working in acid service
- Fabricators building super austenitic spools
- Maintenance teams replacing corroded 316L lines
- Buyers specifying 1.4539 on European projects
Problems It Solves
- Rapid thinning of 316L pipe in reducing acid service
- Loss of corrosion resistance when pipe arrives in the wrong heat treated condition
- Sourcing very large outside diameters in a super austenitic grade
- Surface finish requirements that a mill pickled pipe cannot meet
Application Scenarios
- Sulphuric acid handling and dilution circuits
- Phosphoric acid and fertiliser process lines
- Acetic acid and organic acid plants
- Flue gas cleaning and scrubber piping
Specifications
Every value below is taken from the published product data. Where a figure is not published it is left out rather than estimated.
| Grade | 904L, 1.4539, X1NiCrMoCu25-20-5, UNS S08904 |
|---|---|
| Standard | ASTM A249, A312, A213, A409, A358, A790, JIS G3459, JIS G3463 |
| Outside Diameter | 10 to 1067 mm |
| Wall Thickness | 1.5 to 150 mm |
| Length | 1000 to 13000 mm |
| Surface Finish | 180, 240 or 320 grit polished, mill pickled |
| Delivery Condition | Solution annealed |
| Surface Treatment | Mill finished or polished |
Technical Features
- Very high nickel, molybdenum and chromium content
- Designations 1.4539, X1NiCrMoCu25-20-5 and UNS S08904
- Outside diameter 10 to 1067 mm and wall thickness 1.5 to 150 mm
- Delivery condition solution annealed
- Surface finish 180, 240 or 320 grit polished, or mill pickled
Materials
- 904L super austenitic stainless steel
Manufacturing Process
- Seamless piercing and drawing
- Tube welding
- Solution annealing
- Pickling and polishing
Quality Control
- Chemistry checked against the 904L composition table
- Solution annealed condition confirmed before shipment
- Outside diameter and wall thickness measured against the ordered size
- Surface finish verified against the ordered grit or mill pickled condition
Customisation Options
- Polished to 180, 240 or 320 grit, or supplied mill pickled
- Cut length anywhere in the 1000 to 13000 mm range
- Wall thickness selected from 1.5 mm up to 150 mm
Use Guide
- State whether you need mill pickled or a polished grit level, as the two are priced differently
- Confirm the pipe is supplied solution annealed if the line goes straight into acid service
- Use an over alloyed filler when welding so the weld is not the weakest point
- Passivate the internal surface before commissioning
How It Compares With the Alternatives
| 316L stainless pipe | 904L carries far more nickel and molybdenum plus copper, which is why it stands up in sulphuric, phosphoric and acetic acid where 316L does not |
|---|---|
| 317 stainless pipe | 317 improves on 316 in phosphoric and acetic acid, but 904L goes further in strongly reducing acid service |
| Hastelloy C-276 pipe | C-276 is the choice for wet chlorine and concentrated chloride, while 904L is the economical super austenitic option for acid duty |
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View specifications →904L Stainless Steel Pipe Questions
What outside diameters do you produce
What wall thickness range is available
What delivery condition is the pipe supplied in
Which acids does 904L resist
What surface finishes can you provide
What designations does this grade carry
Quote 904L Stainless Steel Pipe
Send the size, wall or thickness, quantity and destination port. Certificates, packing and lead time are confirmed on the quotation.