Production and NDE - BHDT GmbH

Services we offer

Over decades BHDT has gathered valuable experience as a manufacturer of components for the high-pressure industry. Special attention is paid to the core processes and the depth of production. There is no other manufacturer in this market segment who has in-house production capabilities comparable to those of BHDT. Based on these overall conditions, BHDT is able to offer its customers the safety, quality and consistency which is the basic necessity for high-pressure equipment.

BHDT’s mechanical processing ability ranges from components weighing only a few grams up to more than 20,000 kilogrammes, which is proof of our vertical integration. These processes are all handled in our modern machining park. Turning, milling and honing are performed on our flexible lathes, turning and CNC milling centres and are standard processes for us.

Compared to conventional devices, our machines are equipped with special, purpose-built for the production of high-pressure components. Plant 1 also accommodates an autofrettage-unit as well as several specialized testing units for different valve types. Our in-house standard testing comprises dimensional, surface and visual inspection (VT) as well as ultrasonic (UT), dye penetrant (PT), eddy current (ET) and magnetic particle (MT) testing.

High-pressure tubes are as well manufactured in-house. Multiple deep hole drilling machines, a honing machine, a highly specialized ultrasonic and eddy current testing machine, an end facing machine and a further autofrettage unit are installed there. We are proud to call these machines our own, as only on this production facility basis,

in conjunction with decades of experience, are we able to serve our demanding customers in the high-pressure sector, providing them with top components and complete solutions.

The completion of high-pressure tubes, the assembly of prefabricated units and any welding processes further necessary are carried out by BHDT inhouse. Our well-educated and therefore highly qualified fitters and welders possess numerous different qualifications to cover every single production process requirement of our customers in the field of high-pressure plant construction. Non-destructive testing (NDT) can be considered as standard part of the production process. Additional to VT, UT, PT and MT also x-ray inspection (RT) is executed in-house by sub-suppliers.

Deep hole drilling

  • High precision drilling operation
  • Maximal length 21 meters
  • Solid drilling diameter from 20 mm to 200 mm inside diameter
  • Counter drilling or trepanning up to 300 mm inside diameter


  • High efficiency and high precision honing operation
  • Special process for small diameters and long tubes
  • Maximal length 21.000 m
  • Diameter range: from 20 mm to 200 mm (500 mm)
  • Ra < 0,1 μm


Depending on customer requirements, BHDT produces various types of pipe bends. These can be long-radius or short-radius bends and can also be equipped with a heating jacket.

Different bending processes are applied in the production depending on the required bend radius.

Long-radius bends are produced by cold bending on special bending machines. After the bending process, the bends are stress-relief annealed.

Particularly tight bending radii (short-radius bends) are hot bent by inductive bending or forged in a die, followed by an appropriate heat treatment to achieve the required material properties according to specification.



  • Quality Management Systems ISO 9001
  • Specialized welding company certificate ISO 3834-2
  • China Manufacturing License for Pressure and Super High-Pressure Vessels
  • South Korea Certificate (KGS)
  • Pressure Equipment Directive PED 2014/68/EU
  • ASME U and U3 stamps
  • API Monogram

Manual and semiautomatic welding processes

  • (111) Shielded Metal Arc Welding (SMAW)
  • (135) Gas Metal Arc Welding (GMAW)
  • (136) Flux Cored Arc Welding (FCAW)
  • (141) Gas Tungsten Arc Welding (GTAW)

Semiautomatic welding equipment for hard-facing (wear-resistant) and overlay welding (corrosion-resistant).  These processes are carried out by using special machines from Polysoude.  These machines enable the application of nickel-base alloys and cobalt-base alloys on martensitic chromium steels (1.4021, 1.4006), carbon steels (SA694, SA350), duplex steels (1.4462 – UNS S31803, Ferralium 255), austenitic steels and heat-resistant steels (AISI 4130).

Welding processing of all types of pressure vessel steels according to both national (AD series’ materials) and international standards (ASME, ASTM, API, AISI)

Heat resistant steels with application temperatures
up to 500°C

  • 1.7218, 1.7258, 1.7380, 1.7335

Pressurized hydrogen-resistant steels

  • 1.7779

Carbon steels for high and low temperatures

  • P460NH, P355NH, P355NL1, P690, SA105, SA106Gr.B, SA276, SA350LF2, SA333 Gr.6, SA182 F11

Carbon steels for high and low temperatures for off-shore applications

  • SA694 F65, SA765 Gr. IV, API 5L X52, CSN400, EH36

Duplex and super-duplex steels for on-shore and off-shore applications

  • SA928 Cl.1, SA790 (UNS S31803, UNS S32205, UNS 32750-32760)

Stainless steels and super-austenite steels

  • SA312, SA182 (UNS S31603, UNS S31050, UNS S31254)

Duplex and hyper-duplex steels for the urea industry

  • 1.4462, Ferralium 255, SAFUREX-UNS S32906 a high-alloy duplex stainless steel (hyper-duplex) developed by STAMICARBON and SANDVIK

Austenitic corrosion-resistant steels

  • Processing of all types of austenitic steels such as 1.4435, 1.4466 (urea grades), 1.4571

Titanium alloys

  • Different grades of titanium (e.g. titanium grades 1, 3 ,5)

Nickel-based steels

  • 2.4602 (SB575), 2.4605, Alloy 59, Hastelloy C276, Inconel types

Heat-resistant high-alloy steels

  • SA 182 F304H, SA335 P91, SA182 F91, SA312 F321H

Copper alloys

  • SB 75 (UNS C12200)

Non destructive testing

All our products are multiply tested for technical properties and function to ensure best quality.

BHDT in-house testing procedures:

Ultrasonic testing (UT)

  • Manual and automatic testing units for pipes and tubes of up to 19m in length for detection of surface and internal defects and wall thickness measurement.

Eddy current testing (ET)

  • Automatic testing unit for pipes and tubes of up to 19m in length for detection of surface and near sub-surface defects.

Magnetic particle testing (MT)

  • Manual testing units for detection of surface or near sub-surface defects.

Dye penetrant testing (PT)

  • Manual testing for detection of surface defects like cracks, scratches, surface porosity.

Positive Material Identification (PMI)

  • Alloy verification of materials.

Check of ferrite content

  • Measurement of ferrite content of duplex steels.

Video endoscopy

  • Examination of internal surfaces via endoscope.

Hardness testing

  • Stationary and mobile testing units.

Surface roughness testing

  • Spot check of surface roughness.

Thickness measurement of coating and painting

  • Spot check coating thickness.

Dimensional inspections and visual testing

  • Approx. 2,500 calibrated testing agents for various measurements.

Pressure and tightness testing

  • Testing possibilities with test pressures of up to 1,000 MPa (measuring capability up to 1,400 MPa).

Functional testing

  • Various functional testing possibilities for valves, pumps, power units, etc.

Fatigue testing machine

  • Possibility of performance of leak before burst tests and lifetime evaluations.

Mechanical testing and radiographic testing (RT) are executed in cooperation with external partners.