Pipe Bending for Pulp and Paper Mills
Digester, recovery boiler and stock piping, in materials chosen to survive liquor.
What pulp and paper work brings to a bending shop
Digester and blow line piping, recovery boiler tube and header work, stock and white water lines, evaporator and lime kiln piping.
A pulp mill is a chemical plant with a boiler attached, and both halves are hard on pipe. Black and white liquor are aggressive, so stainless and duplex are common where another industry would use carbon steel, and that makes the metallurgy of the bend part of the specification rather than an afterthought. Recovery boiler work then brings ASME Section I into the same mill.
Codes and standards: ASME Section I on the recovery boiler and B31.1 or B31.3 on the connected piping, with material specifications driven by liquor chemistry. Send your project specification with the enquiry and we will confirm in writing what we certify against before anything is cut.
Shutdowns are short and rare
Mill shutdowns are planned years ahead and measured in days. A bend that arrives late does not get a second window. That makes the documentation package and the schedule as much of the deliverable as the part.
Non-destructive testing and in-plant stress relieving on the same floor as the bend remove two handoffs from that schedule, which is where most of the slippage in this kind of work comes from.
What to send with a pulp and paper enquiry
Five numbers describe a bend: outside diameter, wall thickness, centerline radius, bend angle and the tangent length on each end. Add the material and the quantity and the job can be priced. A drawing, a sketch or a photograph of a marked-up print all work, and the quote form takes an attachment up to 25 MB.
For mill work, send the liquor service and the material grade together. Stainless and duplex appear here where another industry would use carbon steel, and the grade decides the temperature window the bend has to stay inside. Send the shutdown date with the enquiry, because a mill window does not move.
Put the documentation requirements in the enquiry rather than in a later email. Material test reports, non-destructive testing and heat treatment all cost money and time. Retrofitting a documentation package onto a bend that has already been made is slow, and sometimes it is impossible.
Materials we bend
If the grade you need is not listed, ask. This is what comes through most often, not a limit.
What we can bend for you
How we would make it
Wall thickness, radius, material and schedule decide the process. Send the drawing and we will tell you which one fits.
Heat Induction Bending
Cojafex induction bending up through 42″ O.D. and 4″ wall, in any radius, angle or plane.
Coiling
Helical, spiral wound and serpentine coils, cold, up through 10″ pipe.
Cold Bending
Rotary draw bending on fourteen machines, with mandrels and wiper shoes where the radius needs them.
Mandrel Bending
Ball mandrels and wiper shoes for tight radii and thin walls that would otherwise collapse.
Large Diameter Pipe Bending
The work most shops turn away: up to 42 inch outside diameter and 4 inch wall.
Stainless and Alloy Bending
Stainless, duplex, Hastelloy, titanium and nickel alloys, bent without wrecking the metallurgy.
Questions we get from pulp and paper buyers
Can you bend duplex stainless for liquor service?
Yes, including 2205. Duplex needs its phase balance protected through the bend, so send the grade and any ferrite number limits with the enquiry.
Do you do recovery boiler tube work?
The shop holds the ASME S stamp for Section I work and bends and coils tube across the sizes recovery boiler work involves. Send the drawing and the specification and we will confirm scope.
Can you meet a shutdown date?
Tell us the date at enquiry stage rather than after the order. Fourteen cold bending machines and in-house testing and stress relieving are what make a firm date possible, but only if the schedule is priced in from the start.
Have a drawing? Send it over.
Send a drawing or a sketch and our team will get back to you with a quote.