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Flange Gasket for Industrial Valves

Aramid Fiber Flange Gaskets – Asbestos-Free and Certified

The flange gasket is a critical sealing component in industrial valves and pipeline systems. It ensures tight sealing between two flanged connections and reliably prevents leakage of media such as water, steam, gas or chemicals. A high-quality flange gasket significantly enhances operational safety, efficiency and long-term system reliability.

Fergo supplies flange gaskets made of asbestos-free aramid fiber for demanding industrial applications. These gaskets are certified according to recognized standards including Fire Safe, DVGW, WRAS, W270, EEL and BAM. This makes them suitable for potable water systems as well as safety-critical industrial and energy installations.

Our flange gaskets are available in sizes from DN10 (3/8") up to DN300 (12") and designed for flange connections according to PN10, PN16, PN25 and PN40. Aramid fiber flange gaskets offer high pressure and temperature resistance, strong chemical durability and excellent adaptability to flange surfaces, making them ideal for butterfly valves, ball valves and other flanged industrial components.

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PRODUCT CONFIGURATOR

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Product configurator
20 item (s) of 46
HD flange gasket DN 65 PN10/16/25/40 77x127x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-10
HD flange gasket DN50, PN10-PN40, 77x127x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN65 - 2 1/2'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €3.31
€3.94 incl. VAT
Delivery Time: in stock
Available: In Stock
HD flange gasket DN 100 PN10/16 115x162x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-12
HD flange gasket DN100, PN10-PN16, 115x162x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN100 - 4'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €4.31
€5.13 incl. VAT
Delivery Time: in stock
Available: In Stock
HD flange gasket DN 80 PN10/16/25/40 89x149x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-11
HD flange gasket DN80, PN10-PN40, 89x142x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN80 3'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €3.86
€4.59 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN200 PN40 220x290x2 mm metal insert
Product number
Copy to clipboard 515-1014-16
Graphite flange gasket DN200, PN40, 220x290x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN200 - 8'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €38.49
€45.80 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN25 PN10/16/25/40 34x71x2 mm metal insert
Product number
Copy to clipboard 515-1012-06
Graphite flange gasket DN25, PN10-PN40, 34x71x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN25 - 1'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €4.41
€5.25 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN15 PN10/16/25/40 22x51x2 mm metal insert
Product number
Copy to clipboard 515-1012-04
Graphite flange gasket DN10, PN10-PN40, 22x51x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN15 - 1/2'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €2.72
€3.24 incl. VAT
Delivery Time: in stock
Available: In Stock
HD flange gasket DN 150 PN10/16 169x218x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-14
HD flange gasket DN150, PN10-PN16, 169x218x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN150 - 6'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €6.18
€7.35 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN40 PN10/16/25/40 49x92x2 mm metal insert
Product number
Copy to clipboard 515-1012-08
Graphite flange gasket DN40, PN10-PN40, 49x92x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN40 - 1 1/2'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €6.67
€7.94 incl. VAT
Delivery Time: in stock
Available: In Stock
HD flange gasket DN 125 PN10/16 141x192x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-13
HD flange gasket DN125, PN10-PN16, 141x192x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN125 - 5'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €5.46
€6.24 incl. VAT
Delivery Time: in stock
Available: In Stock
HD flange gasket DN 200 PN10/16 220x273x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-16
HD flange gasket DN200, PN10-PN16, 220x273x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN200 - 8'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €9.47
€11.27 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN 50 PN10/16/25/40 61x107x2 mm metal insert
Product number
Copy to clipboard 515-1012-09
Graphite flange gasket DN 50, PN10-PN40, 61x107x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN50 - 2'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €8.68
€9.91 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN20 PN10/16/25/40 27x11x2 mm metal insert
Product number
Copy to clipboard 515-1012-05
Graphite flange gasket DN20, PN10-PN40, 27x61x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN20 - 3/4'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €3.50
€4.16 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN150 PN25/40 169x224x2 mm metal insert
Product number
Copy to clipboard 515-1014-14
Graphite flange gasket DN150, PN25/40, 169x224x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN150 - 6'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €21.56
€25.66 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN150 PN10/16 169x218x2 mm metal insert
Product number
Copy to clipboard 515-1012-14
Grafit flange gasket DN150, PN10-PN16, 169x218x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN150 - 6'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €15.18
€17.33 incl. VAT
Delivery Time: in stock
Available: In Stock
HD flange gasket DN 50 PN10/16/25/40 61x107x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-09
HD flange gasket DN50, PN10-PN40, 61x107x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN50 - 2'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €3.29
€3.92 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN32 PN10/16/25/40 34x71x2 mm metal insert
Product number
Copy to clipboard 515-1012-07
Graphite flange gasket DN32, PN10-PN40, 43x82x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN32 - 1 1/4'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €5.59
€6.65 incl. VAT
Delivery Time: in stock
Available: In Stock
HD flange gasket DN25 PN10/16/25/40 34x71x2 mm aramid fibre asbestos-free
Product number
Copy to clipboard 515-1002-06
HD flange gasket DN25, PN10-PN40, 34x71x2 mm, material made of aramid fibre asbestos-free, approvals: EEL, W270, DVGW, WRAS, EN 1092-1/2
Nominal width :
DN25 - 1'' inch
Certificate :
DVGW
Certificate :
W270
Certificate :
WRAS
Certificate :
EEL
Material:
Aramidfaser asbestfrei
Price €1.57
€1.87 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN200 PN10/16 220x273x2 mm metal insert
Product number
Copy to clipboard 515-1012-16
Graphite flange gasket DN200, PN10-PN16, 220x273x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN200 - 8'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €20.96
€24.94 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN125 PN10/16 141x192x2 mm metal insert
Product number
Copy to clipboard 515-1012-13
Grafit flange gasket DN125, PN10-PN16, 141x192x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN125 - 5'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €13.45
€16.01 incl. VAT
Delivery Time: in stock
Available: In Stock
Graphite flange gasket DN65 PN10/16/25/40 77x127x2 mm metal insert
Product number
Copy to clipboard 515-1012-10
Graphite flange gasket DN65, PN10-PN40, 77x127x2 mm, metal insert, approvals: BAM, Fire Safe, DVGW, EN 1092-1/2
Nominal width :
DN65 - 2 1/2'' inch
Certificate :
DVGW
Certificate :
BAM
Certificate :
Fire Safe
Material:
Grafit
Price €10.82
€12.88 incl. VAT
Delivery Time: in stock
Available: In Stock

Frequently Asked Questions – Flange Gaskets

A flange gasket is a flat sealing element inserted between two flange faces of a pipeline or valve and compressed by the bolt pre-load of the flanged joint. It performs one single but absolutely critical function in the pipeline: creating a pressure-tight, leak-free seal between the two flanges against the process medium – whether water, steam, gas, chemical, or oxygen.

A poor-quality or incorrectly selected flange gasket is one of the most common causes of:
  • Media leakage – with economic, environmental, and safety consequences
  • Pressure losses in the pipeline system – higher energy consumption, reduced plant efficiency
  • Corrosion of flanges and adjacent components from escaping media
  • Unplanned downtime for maintenance and re-tightening
  • Safety hazards with toxic, flammable, or oxidising media
FERGO supplies flange gaskets in two materials – aramid fibre (asbestos-free) for water and general process applications, and graphite with metal insert for gas, steam, and fire-safe applications – both dimensioned to EN 1092-1/2 and carrying comprehensive approvals for critical industrial use.
FERGO offers two flange gasket types that differ clearly in material, approval portfolio, and optimal applications:

HD Flange Gasket – aramid fibre, asbestos-free:
  • Material: Aramid fibre (Kevlar®-like) without metal insert; asbestos-free; uniform thickness 2mm
  • Approvals: EEL (European Extraction Limits for drinking water contact), W270 (DVGW – microbiological innocuousness for drinking water), DVGW (gas and water), WRAS (UK drinking water), EN 1092-1/2
  • Sizes: DN10 to DN300; pressure ratings PN10, PN16, PN25, PN40
  • Strengths: Excellent conformability to flange surfaces; low bolt torque requirement; reliably leak-free even on slightly uneven or lightly corroded flange faces; good chemical resistance to dilute acids, alkalis, water, and steam
  • Preferred use: Drinking water supply; heating and refrigeration systems; general water pipelines; food industry; HVAC; wherever DVGW/WRAS/W270 drinking water approvals are required
Graphite Flange Gasket – graphite with metal insert:
  • Material: Expanded pure graphite with an integrated metal insert (steel or stainless steel) for reinforcement; thickness 2mm; no organic binders
  • Approvals: BAM (German Federal Institute for Materials Research – oxygen and oxidising media), Fire Safe (sealing integrity under fire conditions), DVGW (gas), EN 1092-1/2
  • Sizes: DN10 to DN300; pressure ratings PN10, PN16, PN25, PN40
  • Strengths: Very high temperature resistance (to +400°C continuous); excellent resistance to steam, hot water, hydrocarbons; Fire Safe – the metal insert maintains mechanical integrity even if the graphite burns away under fire conditions; BAM approval for pure oxygen
  • Preferred use: Gases (natural gas, LPG, industrial gases, oxygen); steam systems; hot water; hydrocarbon pipelines; safety-critical installations with fire-safe requirement; butterfly valves and ball valves with Fire Safe certification
Quick selection guide: Drinking water, heating, refrigeration, general water → aramid fibre (HD). Gas, steam, oxygen, Fire Safe, high temperature → graphite with metal insert.
Each approval confirms that the gasket has been independently tested against specific safety and conformity requirements:

DVGW (Deutscher Verein des Gas- und Wasserfaches – German Gas and Water Standards Association):
  • The central German standards body for gas and water installations; DVGW approval confirms that the gasket is authorised for use in DVGW-mandatory drinking water and gas systems
  • Mandatory for installations in public drinking water networks and gas distribution systems in Germany
W270 (DVGW Technical Code W 270):
  • Tests specifically for the microbiological innocuousness of materials in contact with drinking water; confirms that the gasket does not promote microbial growth (biofilm formation) in drinking water
EEL (European Extraction Limits / KTW Guidelines):
  • Tests whether the gasket releases harmful substances into drinking water; extraction of organic compounds, heavy metals, and other substances must remain below defined limits
WRAS (Water Regulations Advisory Scheme):
  • The UK equivalent of the DVGW drinking water approval; required for all materials in UK drinking water installations under the Water Supply (Water Fittings) Regulations 1999
Fire Safe:
  • Confirms that the flange gasket maintains adequate sealing performance under fire conditions (typically 650°C / 30 min per ISO 10497 or API 607); the metal insert of the graphite gasket maintains mechanical stability when the graphite itself has burned away
  • Required for all valves and gaskets in hazardous areas and in the oil and gas industry
BAM (German Federal Institute for Materials Research and Testing):
  • BAM approval certifies suitability for use with pure oxygen (O₂) and other strongly oxidising media; organic materials can self-ignite in oxygen atmosphere under pressure – graphite is inherently non-combustible and therefore suitable for oxygen applications
  • Mandatory in medical technology, air separation plants, welding gas supply, and wherever pure oxygen is handled
The FERGO flange gasket range covers the following dimensions:

Nominal sizes: DN10 (3/8") to DN300 (12") for both gasket types (aramid fibre and graphite)
Pressure ratings: PN10, PN16, PN25, and PN40 – all per EN 1092-1 (Form B, flat face with inner bead) and EN 1092-2
Thickness: Uniform 2mm across all variants

Dimension selection – what to check:
  • Nominal size (DN): Corresponds to the nominal size of the pipeline or valve; the gasket inner and outer diameters are standardised per nominal size and pressure rating in EN 1092-1 – always take exact dimensions from the FERGO catalogue or online configurator (e.g. DN100 PN10/PN16: 115×162×2mm; DN100 PN25/40: different outer diameter)
  • Pressure rating (PN): The gasket pressure rating must be at least equal to the flange pressure rating; PN25 and PN40 flanges have a different bolt circle (different number and diameter of bolts), which results in different gasket outer dimensions than PN10/16 of the same nominal size
  • Form B (flat face with inner bead): All FERGO flange gaskets comply with Form B per EN 1092-1 – the gasket sits on the flange seating face (raised face or flat face) with the bolts passing outside it; ensure correct centring during installation
  • Aramid PN10/16 vs. PN25/40: Reinforced versions with adapted dimensions are available for higher pressure ratings; in case of doubt, always take dimensions from the product configurator on fergo-valve.com/flange-gaskets
Automated valves with pneumatic or electric actuators place higher demands on flange gaskets than manually operated valves, as they cycle more frequently, are exposed to higher dynamic loads, and are used in safety-relevant processes. Gasket selection follows the medium and the valve's certification level:

Butterfly valves:
  • Wafer/lug designs do not require a separate flange gasket between valve and flange – the butterfly valve is clamped between the flanges and seals via the integrated seat lip of the disc seat
  • For flanged butterfly valve designs: graphite gasket for Fire Safe valves; aramid fibre gasket for water/HVAC valves with DVGW drinking water requirement
Ball valves with flanged connection:
  • DVGW-certified ball valves for drinking water: aramid fibre gasket (HD) with W270/WRAS/EEL approval – no organic extractions into drinking water
  • Fire Safe ball valves for gas, oil, and hydrocarbons: graphite gasket with metal insert – Fire Safe and DVGW Gas; maintains the joint seal even under fire conditions
  • TA Luft and ATEX ball valves: graphite gasket preferred; high temperature resistance and chemical compatibility
Knife gate valves:
  • Aramid fibre or graphite depending on medium (slurry, wastewater, chemicals); for chemistry with high temperature or oxidising media: graphite with metal insert and BAM approval
Globe valves and gate valves:
  • Higher pressure ratings PN25/40: graphite gasket with metal insert for adequate surface pressure at higher bolt pre-load; aramid fibre PN25/40 as alternative for drinking water applications
FERGO recommends always selecting the flange gasket to match the valve's certification: Fire Safe valve → Fire Safe gasket; DVGW valve → DVGW gasket. This keeps the approval level of the entire flanged joint consistent.
A high-quality flange gasket can only fully deliver its sealing performance when installed correctly. The most common installation errors and how to avoid them:

Before installation:
  • Clean flange faces: Remove all old gasket residue, rust, dirt, and oil completely; smooth, clean flange faces are essential for uniform surface pressure; repair damaged flange faces (deep scratches, corrosion pitting) before installation
  • Verify correct gasket dimensions: Cross-check nominal size and pressure rating with the flange; particularly for PN25/40, the outer dimensions differ from PN10/16 of the same DN
  • Inspect gasket for defects: Check carefully for cracks, notches, or chipping before installation; never use a damaged gasket
During installation:
  • Centre the gasket: The gasket must be positioned exactly in the centre of the flange face; a displaced gasket causes uneven surface pressure and leakage
  • Lubricate bolts: Apply Molykote or similar lubricant to flange bolts and nuts to achieve even bolt pre-load; dry bolts produce high friction and uneven pre-load
  • Tightening sequence (cross pattern): Always tighten bolts diagonally in a cross pattern – never in a circular sequence; this ensures uniform surface pressure around the full gasket circumference; multiple tightening passes at increasing torque recommended (e.g. 30% → 70% → 100%)
  • Tightening torque: Follow the valve or flange manufacturer's specifications; aramid fibre requires slightly lower torque than graphite gaskets; never exceed the specified torque – aramid fibre gaskets can fracture if over-compressed
  • No sealant: No additional sealant (flange paste, PTFE tape) is required or permitted with quality flange gaskets; sealant on the flange face prevents uniform compression
After installation:
  • First start-up: Check for leakage; re-tighten flange bolts after the first operating pressure application and temperature cycle if necessary (the gasket beds in)
  • Periodic inspection: Regularly inspect flanged connections for leakage traces and bolt corrosion
The graphite flange gasket with metal insert has several material-specific properties that make it the first choice for thermally and chemically demanding, and safety-critical, media:

1. Thermal stability to +400°C:
  • Pure graphite is an inorganic, carbon-based material with an extremely high melting point; it does not creep and does not lose its sealing properties even after long operating periods under high-temperature conditions
  • Aramid fibre begins to degrade above approx. +200–250°C; for steam systems (low-pressure steam 1–6 bar to +165°C; high-pressure steam), graphite is essential
2. Fire Safe property (metal insert):
  • In a fire event, the graphite of the sealing body burns away, but the integrated metal insert maintains the mechanical shape of the gasket and prevents complete loss of sealing function – the joint remains sufficiently sealed to prevent fire propagation through the flanged connection
  • This is the defining requirement of the Fire Safe approval for flange gaskets in the oil and gas industry and in ATEX areas
3. BAM approval for oxygen:
  • Pure oxygen is a powerful oxidiser; organic materials (aramid fibre, PTFE binders, rubber) can self-ignite in pure oxygen atmosphere under pressure
  • Graphite is inorganic and non-combustible; BAM approval certifies that the gasket presents no ignition hazard even in pure oxygen (O₂)
4. Chemical resistance:
  • Graphite is resistant to a wide range of chemicals – hydrocarbons, fuels, oils, many acids and alkalis; no swelling, no dissolution by organic solvents
  • Exception: strongly oxidising acids (concentrated nitric acid, perchloric acid) can attack graphite
Typical graphite gasket applications with FERGO valves: Butterfly valves and ball valves with DVGW gas approval; globe valves (bellows/gland packing) for steam and high temperature; Gestra steam traps; Fire Safe flanged connections in chemical and petrochemical plants.
FERGO offers a complete flange gasket programme for industrial valves and pipeline systems:

Range:
  • HD aramid fibre flange gasket: DN10–DN300, PN10/16/25/40, thickness 2mm; approvals EEL, W270, DVGW, WRAS, EN 1092-1/2 – for drinking water, heating, HVAC, general process applications
  • Graphite flange gasket with metal insert: DN10–DN300, PN10/16/25/40, thickness 2mm; approvals BAM, Fire Safe, DVGW, EN 1092-1/2 – for gas, steam, oxygen, hydrocarbons, high-temperature and fire-safe-mandatory installations
  • From stock for standard nominal sizes; orders from a single unit possible
Matching accessories in the FERGO shop: Advice and ordering:
  • Gasket selection by nominal size, pressure rating, and medium: online configurator on the product page
  • Technical questions and project enquiries: shop@fergo-valve.com | +49 21 31 / 15 39 28-0 | Mon–Fri 8:00–17:00