Klinger gaskets for hydrogen

CG/CGI spiral wound, 316L/Inconel RTJ rings, expanded pure PTFE, pure graphite. ISO 11114-2, TA-Luft qualified, ASME PCC-1 / EN 13555 certified torque factors. For industrial H2, HRS 350/700 bar, biomethane upgrading, refining and ammonia.

Klinger: world standard for industrial seals

The gasket is the most underestimated component in a pressure plant and the one most frequently causing leaks, unscheduled downtime and safety incidents. In hydrogen service the issue is amplified: the H2 molecule, the smallest in the periodic table (kinetic diameter 0.29 nm), penetrates through microscopic surface imperfections or slowly diffuses through apparently inert materials such as PTFE. This is why correct gasket selection is critical.

Klinger, founded in 1886 in Austria, is the world's historic leader in sealing technologies. The hydrogen-service range includes spiral wound with 316L or Inconel winding and graphite or expanded PTFE filler, kammprofile in 316L coated, RTJ rings in soft iron, 316L, Inconel and Monel, expanded high-density pure PTFE gaskets, and pure graphite gaskets for high temperatures. All gaskets have certified m and y factors for bolt torque calculation per ASME VIII / EN 13445 and international qualifications including TA-Luft (fugitive emissions), API 6FA fire-safe, BAM for oxygen service and ATEX.

Roffia distributes the complete Klinger range in Italy with lot traceability, material MTR and technical support for selection and bolt torque calculation.

Klinger types for hydrogen service

Type H2 service Application range
Spiral wound CG (with outer ring)Recommended Class 300–600316L winding + expanded graphite, 316L outer centering ring
Spiral wound CGI (with inner + outer ring)Standard Class 900+ and HRSInconel 625 winding + graphite, dual 316L/Inconel ring blow-out preventive
RTJ rings (R, RX, BX)Permanent metal sealingSoft iron, 316L, Inconel 625/718, Monel — Class 150–2500
KammprofileSpiral wound alternative316L grooved core + graphite/PTFE coating — reusable in some cases
Expanded pure PTFEClass 150–600 / cryogenicsH2 permeability at P>50 bar — prefer graphite for HRS
Pure expanded graphite (Klingrgraph)High temperatureUp to 550 °C in oxidizing atmosphere, 3000 °C in inert. H2 steam reforming service
Fiber with binders (KX, KGS, Sil-C4400)Not recommended for high-pressure H2Standard non-H2 services only (water, air, low steam)

Technical specifications

Parameter Specification
Construction standardsASME B16.20 (RTJ rings), ASME B16.21 (non-metallic flat), EN 12560 (EN RTJ), EN 1514 (EN flat)
DN rangeDN 15 – DN 1500
Pressure classesANSI 150–2500, EN PN 6–400
Temperature range−253 °C (liquid H2) ÷ +1,000 °C (pure graphite) depending on material
H2 compatibilityISO 11114-2 (non-metallic material/gas), ISO 11114-1 (metallic)
QualificationsTA-Luft (BImSchG), API 6FA fire-safe, BAM oxygen, ATEX, FDA for food service
Torque factorsm, y certified ASME PCC-1 — QSmin, QSmax certified EN 13555
DocumentationMaterial MTR, lot traceability, declaration of conformity, TA-Luft qualifications on request

Brand: Klinger

Klinger (founded in 1886) is world leader in gaskets and sealing systems. The portfolio includes flat gaskets in fiber, PTFE, graphite, spiral wound, kammprofile, RTJ rings, gland packings, level indicators and shut-offs for industrial services. The range is qualified with international certifications (TA-Luft, BAM, FireSafe, ATEX, FDA, EHEDG) and supported by a technical database with certified gasket factors for each material, indispensable for ASME / EN calculation.

Roffia srl distributes the Klinger range in Italy for industrial and process plants: we supply material MTRs, lot traceability, qualifications for specific service (hydrogen, oxygen, ammonia, food) and technical support for selection and bolt torque calculation per ASME PCC-1 / EN 13445.

See also the Klinger page on Roffia.com and the general spiral wound gaskets range.

Related hydrogen components

RTJ ring-type-joint flanges →

Ring Type Joint for Class 600–2500 to pair with Klinger RTJ rings.

ANSI flanges for hydrogen →

B16.5 and B16.47 in H2-compatible materials, ISO 11114 dossier.

Hydrogen safety valves →

PED category IV, Ribel brand, free EN ISO 4126 sizing.

Hydrogen ball valves ANSI →

Trunnion-mounted, fire-safe API 607, ANSI Class 150–1500, Ribel brand.

Go to the sector pillar

See a complete overview of Roffia components for hydrogen plants: applications, technical challenges, standards and all dedicated products.

Hydrogen sector — complete overview

Domande frequenti

Which Klinger gaskets are suitable for hydrogen service?
Hydrogen service requires gaskets with ISO 11114-2 qualified materials (non-metallic material/gas compatibility) and high tightness class. Recommended Klinger lines are: spiral wound with 316L or Inconel 625 winding and pure expanded graphite filler (no PTFE because slowly permeable to high-pressure H2) or high-density expanded PTFE; kammprofile in 316L with expanded graphite or PTFE coating for standard service; octagonal and oval RTJ in soft iron, 316L or Inconel for Class 600+; expanded pure PTFE gaskets (Klinger Soft-chem or equivalent) for low-medium pressure H2 service and aggressive chemical environments; pure graphite gaskets for high temperature. Asbestos gaskets are banned in EU since 1992, and alternative fibers (KX, KGS) are acceptable only for standard non-H2 high-pressure service.
What makes Klinger an international standard for industrial gaskets?
Klinger is the world's historic leader (founded in 1886) in industrial sealing technologies. The choice of Klinger for hydrogen plants and hazardous fluids is justified by: (1) complete traceability with material MTR and lot number on every gasket, (2) international qualifications and approvals including TA-Luft (German BImSchG) for fugitive emissions, FireSafe API 6FA, BAM for oxygen service, ATEX certifications, (3) technical database with ASME PCC-1 certified gasket factors (m, y) for each material, indispensable for bolt torque calculation per ASME VIII Div.1 / EN 13445, (4) extensive range of materials qualified for each specific service (oxygen, hydrogen, ammonia, steam, food, cryogenics), (5) application technical support with selection and calculation software. Roffia distributes the complete Klinger range in Italy for industrial plants.
RTJ rings in soft iron, 316L or Inconel — how to choose for H2?
RTJ rings (ring gasket) for ring-joint flanges are selected based on flange material (the ring must be at least 30 BHN softer), pressure, temperature and fluid: Soft Iron (BHN ~90) — very economical, recommended only for low-pressure H2, ambient T, on carbon steel flanges. F5 (4–6% Cr) — low alloy for medium service, standard refining. AISI 316 / 316L (BHN ~160) — standard for industrial H2, stable austenitic, excellent anti-embrittlement compatibility. Pairs with F316L, F22, Inconel flanges. Inconel 625 / 718 — for severe service: high-pressure H2 (Class 1500+), HRS 350/700 bar, H2 + H2S environments, high temperatures. Monel 400 — for cryogenics (liquid H2 at −253 °C) and acidic environments. Roffia supplies Klinger rings in the complete range with MTR 3.1/3.2 and lot traceability.
What is the difference between standard spiral wound and CG / CGI type for hydrogen?
Standard spiral wound gaskets (R type, ASME B16.20) have only the metal-graphite/PTFE winding without centering rings. They are economical but suffer from blow-out at Class 600+ if pressure is cyclic. For H2 service, reinforced variants are preferred: CG type (Centering Guide) — outer 316L centering ring that limits maximum compression and centers the gasket; recommended for Class 300–600. CGI type (Centering Guide + Inner ring) — also adds inner 316L ring that protects the winding from pulsating flow and erosion; mandatory for H2 at Class 900+, hazardous fluids and in all HRS applications. The inner ring also prevents fragmentation of filler (graphite/PTFE) into the pipe, critical in high-pressure H2 lines feeding fuel cells or sensitive catalysts.
How is bolt torque calculated for Klinger gaskets in H2 service?
Calculation follows ASME PCC-1 (flange assembly management) or EN 13555 (gasket characteristics) with Klinger's certified gasket factors: m (gasket factor) and y (minimum design seating stress) for ASME VIII Div.1 calculation; QSmin and QSmax for EN 13445 calculation. Procedure: (1) Calculate minimum sealing force H = (π · G² / 4) · P · m, where G is the gasket effective diameter and P operating pressure. (2) Calculate assembly force Wm1 = πG · y for initial seating. (3) Determine bolt torque for each bolt Tb = K · D · F (K = friction factor, D = bolt nominal diameter, F = target force). (4) Tightening sequence in progressive 30%, 60%, 100% steps in cross pattern. For high-pressure H2, verification with calibrated hydraulic tool and final preload check with ultrasonics or strain gauges is recommended. Roffia provides technical support for torque calculation along with Klinger gasket supply.
Are expanded PTFE gaskets (eGTL) compatible with high-pressure H2?
High-density expanded pure PTFE gaskets (Klinger Soft-chem, KGS-eGTL and similar) are partially compatible with hydrogen service: advantages include chemical inertness toward H2, excellent sealing at low torque (useful on light flanges), no catalysis, thermal range −200 °C ÷ +260 °C. Limits: PTFE is slightly permeable to hydrogen at high pressures (>50 bar) — H2 can slowly migrate through gasket thickness, generating diffuse releases over time. PTFE is also susceptible to cold flow (creep) under cyclic loading, losing preload. Practical guidance: PTFE acceptable up to Class 300–600 in industrial H2 service; for Class 900+ and HRS prefer spiral wound with graphite or metal RTJ; in cryogenic service expanded pure PTFE is recommended thanks to its low elastic modulus that maintains sealing under thermal contraction. Roffia provides technical support for optimal Klinger material selection based on specific H2 service.

Klinger gasket selection for H2 plants

Send us service data (DN, class, pressure, temperature, fluid), flange type and material. We perform optimal Klinger gasket selection, bolt torque calculation per ASME PCC-1, and complete supply with MTR and traceability.

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