Q: How long does it take to manufacture a custom membrane housing?

We deliver standard designs within 10–16 weeks, depending on capacity utilization. More complex housings with thick walls, special materials (Alloy 625, Duplex), or specific internal machining require 16–24 weeks. The design and calculation phase typically takes 4–6 weeks. You will receive detailed timelines after we have finalized your specifications.

Q: How do you handle thermal stresses when the membrane is operating at high temperatures?

For membrane applications with operating temperatures above 400 °C (e.g., palladium metal membranes), we perform thermomechanical FEM simulations using ANSYS. Without exception, we select heat-resistant steels (16Mo3, 13CrMo45, P355NH) or austenitic stainless steels with creep resistance verification in accordance with EN 13445-3, Chapter 19. For highly variable load cycles, a fatigue assessment is performed in accordance with Annex B of EN 13445-3.

Q: What are the advantages of in-house production of housings, piping, and steel structures?

Conventional skid projects distribute vessels, piping, and steel fabrication among three different suppliers. At WOLF, everything is produced under one roof. Specifically, this means for you: • A consistent WPS/PQR strategy across all welded joints—no risk of interface issues • Identical NDT depth for housings and piping—a single Level 3 inspector is responsible • A single set of documents for the entire skid—no piecing together of files from three different subcontractors • Streamlined commissioning: Helium leak testing and pressure test are performed on the complete skid prior to shipment • Clear responsibilities regarding warranty and plant asset monitoring

Q: Are you also able to manufacture large membrane housing skids for industrial plants?

This is precisely our core competency. The individual membrane housings themselves are relatively slim tubular components—the industry standard ranges from 5" to 16" in inner diameter and up to approximately 10 m in length. We deliver the decisive added value at the skid level: We integrate up to a four-digit number of membrane housings onto a large, ready-to-install skid featuring steel structures, operating platforms, and complete high-pressure piping—all manufactured in-house, with a single certified welding engineer and comprehensive inspection documentation. This makes our skids suitable for large-scale projects in the hydrogen economy, in line with Linde’s Path2Zero initiative.

Q: Which standards and certifications do your membrane housings meet?

Our membrane housings are designed and manufactured in accordance with AD 2000, EN 13445, ASME Section VIII Div. 1/Div. 2, and PED 2014/68/EU. We are also certified according to DIN ISO 9001, EN 1090-1/-2 (load-bearing steel structures), and DIN EN ISO 3834 (welding). Upon request, we manufacture in accordance with U.S. requirements, including ASME U, U2, and S stamps.

Q: How do you design the closures to allow for easy replacement of the membrane modules?

Depending on the application, we offer various types of closures: classic flange connections according to EN 1092-1 or ASME B16.5, preloaded high-pressure flanges according to EN 1591-1, and WOLF quick-release closures for tool-free module replacement. The latter are particularly in demand for frequent membrane replacement in research and pilot plants—they allow opening times of less than 5 minutes without bolt preloading.

Q: What surface finishes (roughness values) can be achieved on the interior surfaces of your pressure vessels?

We achieve internal surface finishes of Ra ≤ 0.4 µm—in the areas of sealing surfaces, membrane contact areas, and O-ring grooves, and upon request, Ra ≤ 0.2 µm. As standard, we supply internal surfaces with Ra ≤ 0.8 µm (etched and subjected to passivation). For particularly sensitive applications (semiconductors, pharmaceuticals), we perform electropolishing as a final finish.

Q: What certifications and accreditations does your company have?

We are certified according to international standards to ensure the highest quality and safety: DIN ISO 9001 (Quality Management) PED 2014/68/EU (Pressure Equipment Directive) EN 13445 (Pressure vessel construction) AD 2000 (German standard for pressure vessels) ASME U1, U2, and S stamps (for pressure vessel construction according to U.S. standards / pressure vessels and piping) EN 1090-1/-2 (Construction of load-bearing steel structures) DIN EN ISO 3834 (Welding Technology)

Q: How do your engineers deal with the specific requirements when planning membrane casings for gas separation processes?

When planning membrane casings for gas separation processes such as hydrogen recycling or CO₂ separation, our engineers take into account: Gas-specific requirements: Vessels must be designed for specific gases, such as hydrogen or CO₂, to avoid leaks and ensure correct separation. Pressure and temperature conditions: As these processes often take place under extreme conditions, the design is optimized for high pressure tolerance and thermal resilience. Tightness and integrity: Engineers perform detailed tightness tests and use membrane-based technologies that enable reliable gas permeation.

Question 1

How do you ensure the diffusion tightness of your housings?

Accepted Answer

We employ a multi-stage inspection regimen: 100% visual testing (VT), 100% radiographic or ultrasonic testing (RT/UT) of all pressure-bearing weld seams, helium leak testing with leak rates < 1 × 10⁻⁹ mbar·l/s in the area of sealing surfaces, as well as a pressure test at 1.43 times the design pressure in accordance with EN 13445-5. Upon request, we can supplement the testing with TOFD and phased array testing for weld seams with a wall thickness greater than 30 mm.

Question 2

How long does it take to manufacture a custom membrane housing?

Accepted Answer

We deliver standard designs within 10–16 weeks, depending on capacity utilization. More complex housings with thick walls, special materials (Alloy 625, Duplex), or specific internal machining require 16–24 weeks. The design and calculation phase typically takes 4–6 weeks. You will receive detailed timelines after we have finalized your specifications.

Question 3

How do you handle thermal stresses when the membrane is operating at high temperatures?

Accepted Answer

For membrane applications with operating temperatures above 400 °C (e.g., palladium metal membranes), we perform thermomechanical FEM simulations using ANSYS. Without exception, we select heat-resistant steels (16Mo3, 13CrMo45, P355NH) or austenitic stainless steels with creep resistance verification in accordance with EN 13445-3, Chapter 19. For highly variable load cycles, a fatigue assessment is performed in accordance with Annex B of EN 13445-3.

Question 4

What are the advantages of in-house production of housings, piping, and steel structures?

Accepted Answer

Conventional skid projects distribute vessels, piping, and steel fabrication among three different suppliers. At WOLF, everything is produced under one roof. Specifically, this means for you:

• A consistent WPS/PQR strategy across all welded joints—no risk of interface issues

• Identical NDT depth for housings and piping—a single Level 3 inspector is responsible

• A single set of documents for the entire skid—no piecing together of files from three different subcontractors

• Streamlined commissioning: Helium leak testing and pressure test are performed on the complete skid prior to shipment

• Clear responsibilities regarding warranty and plant asset monitoring

Question 5

Are you also able to manufacture large membrane housing skids for industrial plants?

Accepted Answer

This is precisely our core competency. The individual membrane housings themselves are relatively slim tubular components—the industry standard ranges from 5" to 16" in inner diameter and up to approximately 10 m in length. We deliver the decisive added value at the skid level: We integrate up to a four-digit number of membrane housings onto a large, ready-to-install skid featuring steel structures, operating platforms, and complete high-pressure piping—all manufactured in-house, with a single certified welding engineer and comprehensive inspection documentation. This makes our skids suitable for large-scale projects in the hydrogen economy, in line with Linde’s Path2Zero initiative.

Question 6

Which standards and certifications do your membrane housings meet?

Accepted Answer

Our membrane housings are designed and manufactured in accordance with AD 2000, EN 13445, ASME Section VIII Div. 1/Div. 2, and PED 2014/68/EU. We are also certified according to DIN ISO 9001, EN 1090-1/-2 (load-bearing steel structures), and DIN EN ISO 3834 (welding). Upon request, we manufacture in accordance with U.S. requirements, including ASME U, U2, and S stamps.

Question 7

How do you design the closures to allow for easy replacement of the membrane modules?

Accepted Answer

Depending on the application, we offer various types of closures: classic flange connections according to EN 1092-1 or ASME B16.5, preloaded high-pressure flanges according to EN 1591-1, and WOLF quick-release closures for tool-free module replacement. The latter are particularly in demand for frequent membrane replacement in research and pilot plants—they allow opening times of less than 5 minutes without bolt preloading.

Question 8

What surface finishes (roughness values) can be achieved on the interior surfaces of your pressure vessels?

Accepted Answer

We achieve internal surface finishes of Ra ≤ 0.4 µm—in the areas of sealing surfaces, membrane contact areas, and O-ring grooves, and upon request, Ra ≤ 0.2 µm. As standard, we supply internal surfaces with Ra ≤ 0.8 µm (etched and subjected to passivation). For particularly sensitive applications (semiconductors, pharmaceuticals), we perform electropolishing as a final finish.

Question 9

What certifications and accreditations does your company have?

Accepted Answer

We are certified according to international standards to ensure the highest quality and safety:

DIN ISO 9001 (Quality Management)
PED 2014/68/EU (Pressure Equipment Directive)
EN 13445 (Pressure vessel construction)
AD 2000 (German standard for pressure vessels)
ASME U1, U2, and S stamps (for pressure vessel construction according to U.S. standards / pressure vessels and piping)
EN 1090-1/-2 (Construction of load-bearing steel structures)
DIN EN ISO 3834 (Welding Technology)

Question 10

How do your engineers deal with the specific requirements when planning membrane casings for gas separation processes?

Accepted Answer

When planning membrane casings for gas separation processes such as hydrogen recycling or CO₂ separation, our engineers take into account:

Gas-specific requirements: Vessels must be designed for specific gases, such as hydrogen or CO₂, to avoid leaks and ensure correct separation.
Pressure and temperature conditions: As these processes often take place under extreme conditions, the design is optimized for high pressure tolerance and thermal resilience.
Tightness and integrity: Engineers perform detailed tightness tests and use membrane-based technologies that enable reliable gas permeation.

Question 11

How is the thermal load capacity of membrane casings and hydrogen storage tanks ensured?

Accepted Answer

The thermal load capacity of membrane casings and hydrogen storage tanks is ensured by careful selection of materials and thermal simulations during the planning process. Engineers use finite element analysis (FEA) to simulate the behavior of the material under extreme temperature conditions. In addition, special alloy steels and corrosion-resistant materials are used to ensure the integrity of the vessels at both low and high temperatures.

Question 12

How is the technical planning of a hydrogen storage tank or membrane casing carried out by WOLF?

Accepted Answer

The technical planning of a hydrogen storage tank or membrane housing is carried out in close cooperation with our engineers and taking into account the specific requirements of the project. First, the construction requirements, operating pressure, storage capacity and environmental conditions are taken into account. The design is then created based on standards such as AD-2000, EN 13445, and ASME. Engineers then perform strength calculations and structural analysis to ensure that the vessels can withstand the mechanical and thermal loads.

Membrane technology

Membranes are the heart. We build the protective shell.

Membrane housings in detail

Both pressure-resistant and leak-proof

Meticulously crafted down to the last detail

Everything from a single source: the complete membrane housing skid

quality assurance (QA)

Design in accordance with standards

Your direct
line to us

Diffusion-tight down to the molecular level

Carbon, stainless, and duplex steels

Excellent.

Any questions? We’re here to help you personally.

Details on casings for membrane technology