Chemical Processing
Chemical plant is the hardest specification environment because a single line can see oxidising and reducing conditions in turn, and upset conditions rarely resemble the design case. Material selection has to account for the worst credible chemistry, not the nominal one. This is where the step from 316L through 317L, 904L and Alloy 20 to the C-family nickel alloys is made, and where getting it wrong shows up as an unplanned shutdown.
What gets specified in chemical
Ordered by how commonly they are called for in this sector.
- UNS S31600 / S31603316 / 316LPREN 25
304 plus 2–3% molybdenum. The standard answer to chlorides and mild acids.
- UNS N08904904LPREN 35
High nickel, high molybdenum, with copper. Built for sulphuric acid service.
- UNS N08020Alloy 20PREN 30
Nickel-iron-chromium with copper and niobium. Developed for sulphuric acid.
- UNS N06022Hastelloy C22
Nickel-chromium-molybdenum-tungsten. Resists both oxidising and reducing media.
- UNS S31700 / S31703317 / 317LPREN 30
Higher molybdenum than 316, at 3–4%. The step up before super-austenitics.
- UNS S31803 / S32205 / S32550 / S32750 / S32760Duplex / Super DuplexPREN 41
Roughly equal austenite and ferrite. Around twice the yield strength of 316L.
Applications
06- Reactor vessels and internals
- Acid transfer and storage lines
- Heat exchanger and condenser bundles
- Scrubber and absorber towers
- Pump and valve wetted parts
- Pickling plant equipment
Governing standards
04- ASTM A312
- ASTM A240
- ASME Section VIII
- ASTM B622
Verification available
10- Spectrometer
- Chemical Testing Laboratory
- Positive Material Identification (PMI)
- Spectro Test
- Tensile Testing Machine
- Hardness Testing Machine
- Portable Hardness Tester
- Flattening Test
- Reverse-Bend Test
- Hydrostatic Test Machine
What chemical buys
Other industries
Supplying into chemical?
Send the specification and service conditions. We will confirm the grade, the availability and the documentation you will need.