Manufacturer of seamless, thick-walled pipe bends made of steel and stainless steel, produced in Bünde, Germany.

Siekmann GmbH & Co. KG

Fischerstraße 4, 32257 Bünde, DeutschlandNew on Amplifa

1996Initial ISO 9001 certification

13.9–219.1 mmOuter diameter range

1–55 mmWall thickness depending on outer diameter

BündeLocation Head office, Production, Warehouse

About Siekmann

Siekmann GmbH & Co. KG is a manufacturer specializing in the production of pipe bends from seamless pipe, based in Bünde (North Rhine-Westphalia). The product range includes seamless pipe bends with high wall thicknesses of up to 55 mm depending on outer diameter, special radii, bends with extended legs, angles of 15°, 30°, 45°, 90° and 180° as well as intermediate dimensions in the outer diameter range from 13.9 mm to 219.1 mm. Production is carried out according to EN 10253-2 and -4 (Type A and B), DIN 2605 Part 1 and 2 as well as ASME B16.9, and additionally to customer specifications. Carbon steels, high-alloy steels and stainless steels are processed, including duplex and super duplex materials. In addition, the company offers in-house heat treatment (normalizing, stress-relief annealing, solution annealing), mechanical machining, surface treatment, drawing creation and wall thickness calculation. The pipe bends are used, among other things, in refineries, power plants, gas-fired power stations, oil drilling platforms, heat exchangers as well as in mechanical and plant engineering, and are delivered worldwide.

Site: Bünde
Processes: Pipe bend production from seamless pipe (pipe forming/cold bending), thick-walled, Type A/B per EN, Normalizing/normalisation annealing, Stress-relief annealing, Solution annealing (1020–1080°C, water quench), Material testing, dimensional inspection, hardness testing (Option 15), Drawing creation, wall thickness calculation, Mechanical machining, surface treatment/corrosion protection, Heat treatment (normalizing, stress-relief annealing, solution annealing)
Materials: P235GHTC1/2 (St 35.8 I/III), P265GH (St 45.8), S355J2H, 16Mo3 (15Mo3), 10CrMo9-10 (10CrMo910), 13CrMo4-5 (13CrMo44), X11CrMo5, X11CrMo9-1
Certificates: ISO 9001:2015, DNV, PED 2014/68/EU (97/23/EG), AD2000 W0, PED 2014/68/EU, EN 9100, IATF 16949
Industries: Refineries, Power plant engineering, Gas-fired power stations, Oil drilling platforms, Heat exchanger construction, Mechanical engineering

01
Pipe warehouse with pipe blanks
02
Pipe forming/cold bending into pipe bends
03
Heat treatment (normalizing, stress-relief annealing, solution annealing)
04
Mechanical machining and surface treatment
05
Dimensional inspection and material testing
06
Packaging and shipping (incl. export packaging)

Location

Bünde

Head office, Production, Warehouse

Lot size: Single items and small series
Materials: Carbon steel, high-alloy steel, stainless steel (incl. duplex)

3 centrally computer-controlled heat treatment furnaces (annealing center)
Bending and forming tools for OD 14.0–219.1 mm
Pipe warehouse with pipe blanks

Pipe Bend

**Thick-walled steel pipe bend as high-pressure fitting**Pipe forming · Power plant engineering

**Pipe bend with tight bending radius**Cold bending · Mechanical engineering

**180° pipe bend**Pipe forming · Heat exchanger construction

**Pipe bend Type B**EN 10253 Type B · Refinery

**Pipe bend with orbital chamfer**Orbital chamfer · Piping construction

**Pipe bends in various designs**Cold bending · Plant engineering

Inside the production

Production of thick-walled pipe bends in Bünde

Production view of pipe bend manufacturing

Industries

RefineriesPower plant engineeringGas-fired power stationsOil drilling platformsHeat exchanger constructionMechanical engineeringPlant engineeringPiping construction

Processes & technical limits

Processes	Tolerance	Max. part	Weight	Lot size	Materials
Pipe bend production from seamless pipe (pipe forming/cold bending), thick-walled, Type A/B per ENForming	per pipe bend standards, tighter: bend diameter ±1 mm	–	–	Small series/single items	Carbon steel, high-alloy steel, stainless steel
Normalizing/normalisation annealingHeat treatment	–	–	–	–	Steel, stainless steel
Stress-relief annealingHeat treatment	–	–	–	–	Steel, stainless steel
Solution annealing (1020–1080°C, water quench)Heat treatment	–	–	–	–	austenitic steel, stainless steel
Material testing, dimensional inspection, hardness testing (Option 15)Testing	–	–	–	–	–
Drawing creation, wall thickness calculationEngineering	–	–	–	–	–
Mechanical machining, surface treatment/corrosion protectionSurface	–	–	–	–	–

1 Anlagen & Maschinen

Machine	Manufacturer / model	Quantity	Working area	Year built	Site
Heat treatment furnaces (annealing center, centrally computer-controlled)	–	3	–	–	Bünde

Additional services

Heat treatment (normalizing, stress-relief annealing, solution annealing)Drawing creationWall thickness calculationSmall series productionMechanical machiningSurface treatment / corrosion protectionAdditional material testingSpecial packaging / export packagingExpress deliveryNeutral shipments to end customers

Quality & Certification

The quality assurance system documents and monitors every order from incoming pipe inspection to delivery, supplemented by accompanying dimensional checks, material testing and hardness testing (Option 15). Internal and external audits as well as monitoring by TÜV Nord ensure consistent quality for every bend in a production series.

Evidence	Bünde
ISO 9001:2015
DNV
PED 2014/68/EU
AD2000 W0
EN 9100
IATF 16949

History

1996
Initial certification according to ISO 9001 (per TÜV NORD certificate, certificate registration no. 08 100 969539)