Welded stainless steel tubes for industrial high temperature applications
WITTE HiTEMP’s welded stainless steel tubes are manufactured for use in thermally and chemically demanding processes. To produce a welded stainless steel tube, the tube wall is formed from steel strip and longitudinally seam-welded. This is a tried-and-tested manufacturing process that enables cost-effective production even for large dimensions.
Welded pipes made from stainless, heat-resistant steel offer a reliable solution for pipework systems, vessel construction and thermal process plants. They are used where corrosion and temperature resistance are required, but the application does not necessitate seamless pipes. At our site in Rastede, we hold a wide range of sizes in stock and can supply further sizes at short notice via our global network.
Dimensions and stock programme
WITTE HiTEMP holds welded stainless steel pipe in a wide range of dimensions in stock. Many sizes are available at short notice, and we source further dimensions through our worldwide network. Get in touch with us for advice on availability, dimensions and lead times.
To which standards are welded stainless steel pipes manufactured?
Our welded pipes are manufactured to internationally recognised standards and are supplied as standard with the usual inspection certificates to EN 10204. Individual testing and documentation to customer-specific requirements are available on request.
Available to the following standards, among others:
● EN 10217-7 (DIN EN 10217-7) — welded steel pipes for pressure purposes, stainless steel
● EN 10296-2 — welded circular steel pipes for mechanical and general engineering, stainless steel
● ISO 1127 — dimensions, tolerances and conventional masses for stainless steel pipes
● SEW 470, ASME SA 312, ASTM A 380
Are welded pipes just as strong as seamless pipes?
Yes, for most industrial applications, a stainless steel welded pipe is an equivalent, standard compliant alternative to a seamless pipe. The weld seam is subject to comprehensive testing during manufacture:
● Non-destructive testing (NDT) — ultrasonic, X-ray or eddy-current testing to detect internal defects
● Pressure testing — the pipe is pressurised with water or gas to verify leak-tightness and strength
● Visual inspection — visual check of the seam surface for cracks, pores or irregularities
● Tensile / bend testing — testing the mechanical properties of the weld seam
● Hardness testing — measuring hardness in the seam area and heat-affected zone
● Corrosion testing — testing resistance to chemical exposure, for example via salt spray testing
The key difference lies in the seam factor: for pressurised applications, the permissible operating pressure of a welded pipe is assessed by standard using a seam factor. For applications with very high pressure or strongly fluctuating loads, we recommend seamless pipe.
What pressure ratings do welded stainless steel pipes offer?
The permissible pressure rating of welded pipe results from wall thickness, outside diameter, material and operating temperature, calculated to the applicable standards such as EN 13480, AD 2000 or ASME B31.3. Compared with seamless pipe, the seam factor required by standards must be taken into account for welded pipe, which can reduce the permissible operating pressure by up to 30%.
For pressure critical applications, we work with you to determine whether welded or seamless pipe is the better choice.
Are there differences in corrosion resistance compared to seamless pipe?
With correct manufacture and post treatment, the corrosion resistance of a welded stainless steel pipe is comparable to that of seamless pipe. What matters is the quality of the weld seam and post treatment by pickling and passivation, which neutralises the zone affected by the welding process.
In particularly aggressive media or at elevated temperatures, the weld seam zone can be more susceptible. In these cases, we recommend seamless pipe in acid resistant steel.
Can welded stainless steel pipes be bent?
Welded stainless steel pipe can generally be bent. The position of the weld seam relative to the bending plane must be taken into account: the seam should be positioned in the neutral zone of the bend wherever possible, to minimise mechanical stress at the seam.
For applications with tight bend radii or high dynamic loads, seamless pipe or factory made elbows are the more reliable choice.
What are typical applications for welded stainless steel pipes?
● Chemical and pharmaceutical industry — transport of media, acids, alkalis and ultrapure water
● Food and beverage industry — hygienic piping for liquids and gases
● Oil and gas industry — piping systems for extraction, transport and processing
● Plant and equipment engineering — piping systems in production and process plant
● Heat exchangers and condensers — as inner tubes for heat transfer
● Power plants and energy technology — steam and condensate lines
● Water treatment — corrosion-resistant piping for drinking water and wastewater
● Shipbuilding and offshore — seawater-resistant piping systems
● Mechanical engineering — piping for hydraulic, pneumatic and cooling systems in production plant and machinery
