Sealing board inspection service

Comprehensive Sealing Board Inspection Service for Global Industrial Markets

As an ISO/IEC 17025 accredited laboratory, we provide a dedicated sealing board inspection service that evaluates material composition, mechanical performance, chemical compatibility, thermal stability, and dimensional accuracy. Our sealing board inspection service is designed for manufacturers and exporters of gasket sheets, industrial sealing materials, and compressed fiber boards who must demonstrate conformity to ASTM, EN, ISO, and regional pressure equipment directives across the European Union, North America, the Middle East, and Asia Pacific. Every test is performed under our CNAS-accredited quality system, producing reports that are accepted by notified bodies, plant inspectors, and procurement authorities worldwide.

Product Samples We Regularly Test in Our Sealing Board Inspection Service

Non-asbestos compressed fiber sealing boards — aramid, mineral fiber, and carbon fiber reinforced gasket sheets with NBR or SBR binders
PTFE and expanded PTFE sealing boards — pure, filled, and micro-cellular PTFE sheets for chemical and food-grade applications
Graphite and reinforced graphite sealing boards — flexible graphite sheets with stainless steel foil insertion for high-temperature flanges
Rubber and elastomeric sealing boards — neoprene, EPDM, nitrile, silicone, and fluoroelastomer sheets for general sealing
Cellulose and vegetable fiber sealing boards — for oil, fuel, and moderate temperature applications
Mica and ceramic fiber sealing boards — for extreme temperature, fire-resistant, and thermal barrier applications
Multi-layer and composite sealing boards — laminated structures combining PTFE, graphite, and metal reinforcement

Physical and Mechanical Property Testing for Sealing Boards

Density and specific gravity per ASTM F104 and ISO 2781 — the mass per unit volume of the sealing board is determined to verify compound consistency, identify voids or porosity, and calculate material consumption for gasket production.
Transverse tensile strength per ASTM F152 and ISO 527-3 — the sealing board is subjected to a controlled tensile force until rupture to measure the minimum tensile strength required to withstand flange assembly stress and internal pressure without tearing.
Compressibility and recovery per ASTM F36 and BS 7531 — the board is compressed under a defined load and the percentage compression is recorded, then the load is released and the percentage recovery is measured. This test is the primary indicator of a sealing board's ability to conform to flange irregularities and to maintain bolt load over time.
Creep relaxation and hot compression performance per ASTM F38 and EN 13555 — the gasket sheet is compressed between heated platens and the residual stress is monitored over time to quantify the loss of sealing force at elevated temperature, providing design data for flange joint integrity calculations under thermal cycling.
Bending strength and flexibility per ISO 178 and ASTM D790 — the board is subjected to a three-point bending test to ensure it can be cut and handled without cracking, especially for thin or brittle grades used in delicate flange applications.

Chemical Compatibility and Fluid Resistance Testing of Sealing Boards

Immersion testing in process fluids per ASTM F146 and ASTM D471 — the sealing board is fully immersed in oils, fuels, solvents, acids, alkalis, and heat transfer fluids at a defined temperature for a specified duration. The change in mass, thickness, tensile strength, and compressibility is measured to confirm chemical compatibility with the intended service medium.
Oil absorption and sealability after immersion per ASTM F37 and customer protocols — the board is subjected to a standard test fluid under pressure in a flange simulator, and the leak rate is measured both before and after chemical aging to ensure the sealing function is maintained in aggressive environments.
Water and steam resistance per ASTM F146 and ISO 1817 — the board is exposed to hot water or steam at elevated temperature and pressure, then tested for dimensional change, weight change, and mechanical property retention to confirm suitability for water, steam, and condensate service.
Resistance to refrigerants and compressor oils per DIN 3754 and ASHRAE 97 — for sealing boards used in HVAC and refrigeration systems, compatibility with R134a, R32, R410A, and polyolester oils is verified by sealed tube testing and post-exposure mechanical evaluation.

Thermal Stability and High-Temperature Performance Testing

Weight loss on ignition and binder content per ASTM F104 and ISO 3451-1 — the sealing board is heated to a defined temperature to determine the organic binder and fiber content, verifying the compound formulation and predicting high-temperature resistance.
Thermal aging and heat resistance per ASTM F38 and ASTM D573 — the board is aged in a ventilated oven at elevated temperature for extended periods, then the retained tensile strength, compressibility, and recovery are measured to predict service life at the rated maximum temperature.
Thermal conductivity and thermal expansion per ASTM E1530 and ASTM E831 — for sealing boards used in heat exchanger and cryogenic applications, the thermal conductivity and coefficient of thermal expansion are measured to confirm compatibility with adjacent metal components and to prevent thermal stress failures.
Short-term maximum temperature and hot blow-out resistance per DIN 52913 and customer protocols — the board is tested in a pressurized flange assembly at increasing temperature to determine the maximum temperature at which the seal remains tight without blow-out or extrusion.

Fire Resistance and Flammability Testing for Sealing Boards

Euroclass reaction-to-fire classification per EN 13501-1 — the sealing board is tested for ignitability (EN ISO 11925-2) and contribution to fire growth (EN 13823) to generate the classification required for CE marking of construction products used in building services and fire protection systems.
Surface burning characteristics per ASTM E84 — the flame spread index and smoke developed index are determined for sealing boards used in North American building and industrial applications to verify Class A or Class B fire performance.
Glow-wire and hot-wire ignitability per IEC 60695-2-11 — for sealing boards in electrical enclosures and switchgear, the resistance to ignition from an overheated contact is evaluated to ensure no flame propagation occurs.
Limiting oxygen index per ISO 4589-2 — the minimum oxygen concentration supporting combustion is measured to rank the relative fire resistance of different sealing board formulations for quality control purposes.

Asbestos Content and Restricted Substance Compliance for Sealing Boards

Asbestos fiber detection and quantification per ISO 22262-1 and ASTM D7521 — the sealing board is analyzed by polarized light microscopy and transmission electron microscopy to confirm it is free of asbestos fibers, a mandatory requirement for all sealing products imported into the European Union, North America, and Asia.
RoHS compliance per IEC 62321 and EU Directive 2011/65/EU — screening and quantitative analysis for lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers in the board, binder, and any surface coatings.
REACH Annex XVII and SVHC screening — targeted analysis of Substances of Very High Concern including short-chain chlorinated paraffins, specific phthalates, and heavy metal compounds that may be present in the sealing board raw materials or additives.
Polycyclic aromatic hydrocarbons per AfPS GS 2019:01 PAK — for carbon-filled or graphite-based sealing boards, the 15 restricted PAHs are quantified to confirm compliance with European consumer product safety limits.
Leachable chloride and fluoride content per ASTM F104 and internal methods — the sealing board is extracted with water and the leachate is analyzed for corrosive ions to ensure the board is suitable for stainless steel flanges without inducing pitting or stress corrosion cracking.

Dimensional and Visual Quality Inspection of Sealing Boards

Thickness, width, and length measurement per ASTM F104 and ISO 1923 — laser micrometers and digital callipers verify that the board dimensions fall within the specified tolerance class for sheet and roll products, ensuring consistent gasket cutting and flange fit.
Surface finish and defect inspection per ASTM F104 and customer specifications — systematic examination under controlled illumination for surface pits, cracks, blisters, foreign inclusions, and non-uniform color that could indicate incomplete mixing or contamination.
Edge quality and lamination integrity — for multi-layer sealing boards, the edge is inspected for delamination and the bond strength between layers is verified by a peel or tensile test per ASTM D1876 to ensure the laminate remains intact during gasket cutting and service.

Report Recognition and ISO/IEC 17025 Compliance

All methods described in this sealing board inspection service are covered by our ISO/IEC 17025 scope of accreditation. Our test reports are accepted by European notified bodies under the Pressure Equipment Directive, by North American engineering firms and plant operators referencing ASME B16.20 and ASTM standards, and by customs and regulatory authorities across the Middle East, Australia, and Asia. Whether you require a full material qualification for a new non-asbestos sealing board, a batch release inspection for an export shipment, or a root cause failure analysis of a gasket joint, our laboratory provides the measurement accuracy and technical depth that the global fluid sealing industry demands.