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Piping Construction

Industrial Services for Piping Construction

In piping construction, prefabrication and assembly determine schedules, weld quality and cost. Pipe spools must be cut to length, cleanly bevelled and prepared for welding — on site as well as in prefabrication.

HSOS supports prefabrication and assembly with machined pipe cutting, precise beveling for all common weld preparations, controlled preheating and post-weld heat treatment (PWHT) on thin- and thick-walled joints. Spark-free cold cutting without heat input is possible even in hazardous or live-plant areas.

Documentation to AD 2000, ASME and project-specific codes — audit-ready and traceable.

Practical know-how for site and project managers

Reference pages for work on existing plants and international projects – compiled from our practical experience on site.

Project sequence

Piping installation sequence

Ten phases from pipe class to commissioning: what must be done beforehand, where HSOS comes in and what follows.

Preparing a pressure test properly

Checklist before, during and after the test, test pressure to EN 13480-5 and ASME B31.3, blinds and blind list.

Stress relieving guide values

Holding temperature, thickness limit and holding time by material to EN 13480-4 and ASME B31.3, plus preheating and measurement.

Flange distortion during welding

Why flange faces distort, how to prevent it and how they are made flat again on site.

Cold cutting instead of flame cutting

Pipe cutting without a heat-affected zone: when it pays off for creep-resistant and stainless steels.

Piping standards old and new

DIN 2448, DIN 2633, ND 16, St 35.8: old designations on as-built drawings and the EN, ISO and ASME standards that apply today.

Piping glossary English–German

Around 230 technical terms and isometric abbreviations – from elbow and spectacle blind to BOP – with search and notes on typical mistranslations.

Weld preparation

Pipe bevel overview

Joint types to EN ISO 9692-1 and ASME B16.25, unequal wall thicknesses and bevels on branches.

Flange facings and surface finish

Flange types to EN 1092-1, roughness by gasket type, and weld lip seals.

Width across flats table

Widths across flats and thread pitches M6–M100 and ¼″–4″ – and what they mean for torque and bolt tensioning.

Challenges

▸Accurate cutting and beveling for weld-ready joint preparation
▸Tight schedules in prefabrication and site assembly
▸Controlled preheating and PWHT across varying wall thicknesses
▸Machining without sparks and heat input in live-plant areas
▸Traceable documentation per weld and component

Our experience

✓Machined pipe cutting and beveling from DN 25 to DN 3000
✓Weld preparation (V, U, compound bevels) to WPS
✓Controlled preheating with resistance and induction techniques
✓Post-weld heat treatment (PWHT) to AD 2000 HP 7/1 and ASME PCC-2
✓Spark-free cold cutting in Ex and live-plant zones

References

Pipe prefabrication DE

Cutting, beveling and weld preparation of spools

Result: On-schedule prefabrication, documented bevels

Site assembly EU

Preheating and PWHT on assembly welds

Result: Approved without rework

Chemical plant extension

Spark-free cold cutting during live operation

Result: No production loss

Relevant services

Hot Tap & Line Stop

Hot Tap & Line Stop

Composite Repair

Composite Repair

FAQ

Do you work in prefabrication and on site?

Yes — pipe cutting, beveling, preheating and PWHT both in prefabrication and during on-site assembly.

Which pipe sizes do you handle?

Machined cutting and beveling typically from DN 25 to DN 3000, larger diameters on request.

Can you cut without heat input?

Yes — spark-free cold cutting with no heat input, including Ex and live-plant areas.

Always available – fast on site

Less downtime, less production loss. Contact us – 24/7.

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