Non asbestos jointing sheets are made of special non-asbestos heat resisting fiber ,Heat-resisting packing material and natural rubber compound heating and compression molding it.These are the substitutes of corresponding models of asbestos rubber sheet.These are used for the equipment in water and steam etc and used as sealing material in the joints of pipeline.They can withstand a working pressure of 40 bar/600 psi and working temperatures upto 400c.
Asbestos-free — aramid fibre with NBR binder
The general-purpose flange gasket sheet for steam & oil
Compressed non-asbestos jointing sheet is the general-purpose flange gasket material of industry — the sheet you cut a gasket from when the duty is ordinary steam, water, oil or general process service. It is made from aramid fibre bonded with nitrile (NBR) rubber and hot-calendered into a dense, uniform sheet that cuts cleanly and seats reliably.
It exists as the direct, safe replacement for asbestos jointing sheet, and for the great majority of flange joints it performs equivalently. Where it genuinely differs from asbestos-based sheet is at the extremes: standard non-asbestos grades run to roughly 200–280°C, whereas asbestos jointing sheet extends further. For everything below that, non-asbestos is the correct choice, and there is no performance reason to reach for asbestos.
An honest word on grades. "Non-asbestos jointing sheet" is a material family, not a single specification. A standard commercial grade and a premium high-temperature grade differ substantially in temperature ceiling, pressure rating and creep behaviour — and they look identical. When comparing quotes, compare the actual figures (temperature, pressure, ASTM F36 compressibility and recovery, F38 creep relaxation), not just the description. Tell us your line conditions and we will confirm which grade you actually need.
Most non-asbestos gasket failures we see are not material failures at all — they are bolt-tightening failures. See the installation section below, and our bolt torque sequence guide.
Specifications
Typical properties for compressed aramid/NBR non-asbestos jointing sheet. Ranges reflect the genuine spread between standard and premium grades — confirm the grade against your line conditions.
Property
Value
Test Standard
Material
Aramid fibre with NBR (nitrile) rubber binder
—
Manufacture
Hot-calendered compressed sheet
—
Colour
Typically green or grey (grade-dependent)
—
Max Temperature — standard grade
~200 – 210°C
—
Max Temperature — premium grade
up to ~280°C
—
Max Pressure — standard grade
~20 bar
—
Max Pressure — premium grade
up to ~60 bar (grade-dependent)
—
Compressibility
7 – 17%
ASTM F36
Recovery
40 – 50% (minimum)
ASTM F36
Creep Relaxation
< 20% (premium) to ~27% (standard)
ASTM F38
Density
~1.6 – 1.9 g/cm³
—
Thickness Range
0.5 mm – 5 mm
—
Standard Sheet Size
1500 × 1500 mm; also 1.5 m × 4.5 m to order
—
Media Suitability
Steam, water, oils, fuels, mild chemicals, gases
—
Oil Resistance
Good — the NBR binder is oil-resistant by design
—
Asbestos Content
None
—
Classification
Compressed fibre sheet gasketing
ASTM F104
Properties in Detail
Sealing Performance
Compressibility (F36)
7 – 17%
Recovery (F36)
40 – 50%
Creep Relaxation (F38)
< 20% – 27%
Why It Matters
Low creep = the joint holds bolt load and does not leak
Service Limits
Max Temp (standard)
~200 – 210°C
Max Temp (premium)
up to ~280°C
Max Pressure
~20 bar standard / up to ~60 bar premium
Above These Limits
Use asbestos jointing sheet or a PTFE/spiral-wound gasket
Media & Chemical
Steam & Water
Good — core duty
Oils & Fuels
Good (NBR binder)
Mild Chemicals
Fair
Aggressive Acids
Poor — use PTFE sheet instead
Manufacturing
The sheet is produced by a hot-calendering process: aramid fibre, nitrile rubber binder and fillers are compounded and then rolled under heat and very high pressure onto a large drum, building the sheet up in thin layers until the required thickness is reached. The result is dense, uniform, and far more consistent than a simple pressed board.
The two components do different jobs, and understanding this tells you what the material can and cannot do. The aramid fibre provides mechanical strength and resistance to blow-out under pressure — it is what stops the gasket being extruded out of the flange. The NBR (nitrile) binder provides the sealing and the chemical character: NBR is inherently oil-resistant, which is exactly why this material handles oils and fuels well, and also why it is only fair against aggressive solvents and acids, which attack nitrile.
Grade differences come from the fibre-to-binder ratio, the fibre quality and the filler package. This is why two sheets that look identical can have materially different temperature ceilings and creep behaviour — and why the datasheet figures matter more than the description.
Thickness & Sheet Sizes
Standard jointing sheet stock. Thinner gaskets seal better (less material to creep and relax) — use the thinnest sheet that will accommodate your flange surface finish and any distortion.
Thickness
Sheet Size
Typical Use
0.5 mm
1500 × 1500 mm
Precision flanges, good surface finish
0.8 mm
1500 × 1500 mm
General flanges, thin gaskets
1.0 mm
1500 × 1500 mm
Most common general-purpose gasket
1.5 mm
1500 × 1500 mm
General flanges, standard duty
2.0 mm
1500 × 1500 mm
General flanges, slight surface irregularity
3.0 mm
1500 × 1500 mm
Rougher flange faces, manhole covers
4.0 mm
1500 × 1500 mm
Poor flange faces, large joints
5.0 mm
1500 × 1500 mm
Heavy duty, uneven faces
Use our Gasket Sheet Usage Calculator to work out how many sheets your gasket run needs, including cutting wastage. We can also cut gaskets to your drawing or flange dimensions.
Chemical Resistance
Chemical behaviour is driven by the NBR binder. NBR is oil-resistant by nature, which is this material’s strength — and it is attacked by solvents and strong acids, which is its weakness.
Medium
Resistance
Notes
Steam & Hot Water
Good
Core duty — within the temperature limit
Mineral Oils & Fuels
Good
The NBR binder is oil-resistant by design
Gases (air, nitrogen)
Good
Standard flange duty
Alcohols
Good
Suitable
Mild Acids
Fair
Limited — confirm concentration and temperature
Strong Acids
Fair
Use PTFE sheet instead for aggressive acid service
Strong Alkalis
Fair
Limited — confirm with us
Aromatic / Ketone Solvents
Fair
NBR is attacked by solvents — PTFE is the correct choice
Chlorine & Oxidizers
Poor
Not recommended
General guidance for the material family at normal industrial concentrations. See the full Chemical Compatibility Chart, and confirm your exact chemical, concentration and temperature with us before final selection.
Applications
The general-purpose gasket sheet for the majority of flanges in a plant.
Flange GasketsThe core application — full-face and ring gaskets cut for pipeline flanges on steam, water, oil and general process lines. This is the material most flanges in a plant are sealed with.
Steam & Condensate LinesStandard steam service within the temperature and pressure limits. For superheated steam above the grade limit, step up to asbestos jointing sheet or a spiral-wound gasket.
Oil & Fuel SystemsThe NBR binder is inherently oil-resistant, making this a natural fit for lubricating oil, hydraulic and fuel line flanges.
Pump & Valve Body GasketsCasing gaskets, cover joints and body seals on pumps, valves and general rotating equipment.
Manhole & Cover PlatesTank manways, inspection covers and access plates, where thicker sheet accommodates a less-than-perfect sealing face.
Heat Exchanger GasketsShell and cover gaskets on heat exchangers operating within the temperature and media limits of the grade.
Industries
Why Non Asbestos Jointing Sheet is specified in each of the industries we serve.
Power Plants
A power station has hundreds of flanged joints, and the great majority of them are ordinary duty — feedwater, condensate, service water, lubricating oil, compressed air. Non-asbestos jointing sheet is the correct and economical material for all of these, and standardising on it for general service keeps both cost and stores complexity down. The discipline that matters is knowing where it stops: the high-temperature steam side, and superheated lines in particular, run beyond what a standard non-asbestos grade will hold, and those joints need a higher-temperature material or a spiral-wound gasket. The other thing worth being blunt about in a power plant context is that most gasket leaks are not caused by the gasket at all — they are caused by bolts tightened in a circular sequence instead of a star pattern, which pinches the flange and crushes the gasket unevenly. Getting the bolting right eliminates most of the leaks.
Chemical Plants
In a chemical plant the deciding question for any gasket is the media, and this is where non-asbestos jointing sheet has to be applied with some judgement. Its NBR binder makes it genuinely good on oils, fuels, water, steam and gases — which covers a great deal of a plant’s utility and service pipework. But nitrile is attacked by aggressive solvents and strong acids, and on those process lines this material will fail, sometimes quickly. The correct choice there is PTFE sheet, which is chemically inert across the full pH range. The practical approach in a chemical plant is therefore to use non-asbestos jointing sheet everywhere the media is benign, reserve PTFE for the genuinely aggressive lines, and resist the temptation to standardise on a single material for both — one is unnecessarily expensive, the other unsafe.
Sugar Mills & Food Processing
Sugar mills and general food-processing plants run extensive steam, hot-water, juice and utility pipework, and non-asbestos jointing sheet is the economical general-purpose gasket for all of it. It handles the steam and hot water side comfortably within its temperature range and copes well with the oils and lubricants around the mill machinery. The one caution is product contact: standard non-asbestos jointing sheet is not a food-grade material, and it should not be used on lines where the gasket is in direct contact with the product. For those joints, food-grade PTFE sheet or food-grade silicone rubber sheet is the correct specification. Keeping the two clearly separated — general utility gaskets versus product-contact gaskets — is the thing to get right.
Textile Mills & General Industry
General manufacturing runs steam distribution, hot water, compressed air, hydraulic and lubricating oil systems, and non-asbestos jointing sheet is the default gasket material across essentially all of them. Its combination of low cost, easy cutting and good oil and steam resistance is exactly what general engineering service needs, and holding a couple of thicknesses in stores covers most flange work in a plant. In a textile mill specifically, the exception to watch is the dyeing and bleaching side, where hot chemically-active liquor will attack the nitrile binder — those lines need PTFE. Elsewhere in the mill, from the boiler house to the compressor room, non-asbestos jointing sheet cut to the flange profile is the straightforward, correct and cheapest answer.
Non-Asbestos Jointing vs Other Gasket Sheets
Non-asbestos jointing sheet is the sensible default. Step away from it only when the temperature, pressure or chemistry genuinely demands something else.
Property
Non-Asbestos Jointing
Asbestos Jointing
PTFE Sheet
Silicone Rubber
Max Temperature
~210°C (up to 280°C premium)
~450 – 500°C
260°C
230°C
Max Pressure
~20 bar (up to ~60 premium)
up to ~100 bar
Moderate
Low
Chemical Resistance
Fair (good on oils)
Fair
Excellent (pH 0–14)
Fair
Oil Resistance
Good (NBR binder)
Good
Excellent
Poor
Creep / Cold Flow
Low — holds bolt load
Low
High — needs re-torque
Low
Food Grade
No
No
Yes (FDA grade)
Yes (food grade)
Asbestos-Free
Yes
No
Yes
Yes
Relative Cost
Low
Low
High
Medium
Choose It For
General steam, oil, water flanges
Highest-temp steam
Aggressive chemicals
High/low temp, food
Advantages & Limitations
Advantages
Asbestos-free — no handling, disposal or regulatory burden.
The economical general-purpose gasket sheet: covers the majority of flanges in a plant.
Good oil and fuel resistance, thanks to the NBR binder.
Low creep relaxation — it holds bolt load far better than PTFE, so joints stay tight without repeated re-torquing.
Cuts and punches cleanly to any flange profile with basic tools.
Good compressibility and recovery, so it conforms to imperfect flange faces.
Dimensionally stable and easy to store.
Limitations
Temperature ceiling of roughly 210°C for standard grades (up to ~280°C for premium). Not suitable for superheated steam — use asbestos jointing sheet or a spiral-wound gasket above the limit.
The NBR binder is attacked by solvents and strong acids. For aggressive chemical service, PTFE sheet is the correct material.
Not food-grade. Do not use it on product-contact joints; specify food-grade PTFE or silicone instead.
"Non-asbestos jointing sheet" is a family, not one spec — grades differ significantly in temperature, pressure and creep. Compare datasheet figures, not descriptions.
Not suitable for chlorine or strong oxidising media.
Performance is highly dependent on correct bolt tightening — most failures are installation errors, not material failures.
Installation, Storage & Maintenance
Installation
This is where most non-asbestos gasket failures actually come from, so it is worth doing properly. Clean both flange faces completely and check them for scoring — a damaged face will leak regardless of the gasket. Cut the gasket to the exact flange profile with a sharp blade or die. Then tighten the bolts in a star (criss-cross) pattern in stages — roughly 30%, 60%, then 100% of final torque — never in a circle. Tightening sequentially around the flange pinches one side closed while the other is still gapped, crushing the gasket unevenly. Use the correct torque for the flange class, and re-check after initial pressurisation and heat-up. Full detail in our bolt torque sequence guide.
Storage
Store sheets flat, dry, and out of direct sunlight, ideally in their original packaging. Do not store them leaning or rolled, as they can take a permanent bow that makes accurate gasket cutting difficult. Keep them away from oils and solvents in storage, and away from heat sources. Stored flat and dry, jointing sheet has a long and stable shelf life.
Maintenance
A gasket is a one-time-use item — never re-use a jointing sheet gasket once a joint has been broken. The gasket has already compressed and taken a set to that particular flange, and it will not seal reliably a second time. Always cut a fresh gasket. At scheduled shutdowns, re-check bolt torque on joints that have been through heat cycles, and inspect flange faces for scoring or corrosion while they are open.
Buying Guide
What to tell us so we quote the right grade first time.
Line temperature and pressure. These determine the grade. Standard grades run to about 210°C and 20 bar; premium grades go further. Do not assume — many lines that people think need a premium grade are comfortably inside standard range.
What is the media? Steam, water, oil, fuel and gases are all fine. If there are aggressive solvents or strong acids, tell us — the NBR binder will be attacked and you need PTFE sheet instead.
Is it product contact? If a food, dairy or pharmaceutical product touches the gasket, this material is not suitable. You need food-grade PTFE or silicone.
Thickness. Thinner gaskets seal better because there is less material to creep and relax. Use the thinnest sheet your flange surface finish will allow — go thicker only to accommodate a rough or distorted face.
Sheet, or cut gaskets? We supply plain sheet for you to cut, or we cut gaskets to your drawing, template or flange dimensions. The Gasket Sheet Usage Calculator will tell you how many sheets a gasket run needs.
Flange class (for bolt torque). Worth confirming, because using the wrong torque — or the wrong tightening sequence — causes more gasket leaks than any material shortcoming.
Standards & Compliance
ASTM F104 — classification system for non-metallic gasket materials.
ASTM F36 — compressibility and recovery of gasket materials.
ASTM F38 — creep relaxation of gasket materials.
ASTM F152 — tensile strength of gasket materials.
Contains no asbestos — a direct replacement for asbestos jointing sheet in the majority of general service.
Certificates of conformity and full grade datasheets available on request — ask for the ASTM F36/F38 figures when comparing grades.
Aramid fibre bonded with nitrile (NBR) rubber, hot-calendered into a dense sheet. The aramid gives strength and blow-out resistance; the NBR gives sealing and the oil resistance.
What temperature can it handle?
Standard grades run to roughly 200–210°C. Premium grades reach up to about 280°C. This is genuinely grade-dependent, so confirm the figure for the sheet you are actually buying.
What pressure can it handle?
Around 20 bar for standard grades, up to about 60 bar for premium grades. As with temperature, the grade matters.
Is it as good as asbestos jointing sheet?
For the vast majority of service, yes — performance is equivalent and there is no reason to use asbestos. The genuine difference is at the top end: asbestos jointing sheet extends to roughly 450–500°C and higher pressure classes, which standard non-asbestos grades do not reach.
Why does my gasket keep leaking?
Most often, the bolts. Tightening in a circular sequence instead of a star pattern pinches the flange and crushes the gasket unevenly. Tighten in a star pattern in stages (30% / 60% / 100%), and re-check after the first heat and pressure cycle. That fixes the majority of leaks.
What is the correct bolt tightening sequence?
A star or criss-cross pattern — always tighten bolts opposite each other, never adjacent ones in sequence. Do it in three passes at roughly 30%, 60% and 100% of final torque. See our torque sequence guide.
What thickness gasket should I use?
The thinnest your flange faces will allow. Thinner gaskets seal better because there is less material to creep and relax under load. Go thicker only to accommodate a rough, pitted or distorted sealing face.
Can I re-use a gasket?
No. Once a joint has been made and broken, the gasket has compressed and taken a permanent set to that flange. Always cut and fit a fresh gasket — re-using one is a very common cause of leaks.
Can I use it for oil and fuel?
Yes — this is one of its strengths. The NBR binder is inherently oil-resistant, so lubricating oil, hydraulic and fuel line flanges are well within its capability.
Can I use it for aggressive chemicals?
No. Nitrile is attacked by solvents and strong acids. For aggressive chemical service you need PTFE sheet, which is inert across the full pH range.
Is it food-grade?
No. Do not use it where the gasket contacts food, dairy or pharmaceutical product. Specify food-grade PTFE or food-grade silicone rubber sheet for those joints.
Can I use it for superheated steam?
Not above the grade limit. Standard non-asbestos will not survive superheated steam. Use asbestos jointing sheet, a high-temperature grade, or a spiral-wound gasket.
What do ASTM F36 and F38 mean?
F36 measures compressibility and recovery — how much the gasket squashes under load and how much it springs back. F38 measures creep relaxation — how much bolt load the gasket loses over time. Low creep relaxation is what keeps a joint tight, and it is the figure most worth comparing between grades.
Does it creep like PTFE?
Far less. This is one of its real advantages over PTFE: non-asbestos jointing sheet holds bolt load well, so joints stay tight without the repeated re-torquing that PTFE gaskets demand.
What sheet sizes do you supply?
Standard 1500 × 1500 mm, with 1.5 m × 4.5 m available to order. Thicknesses from 0.5 mm to 5 mm.
How many sheets do I need for my gasket run?
Use our Gasket Sheet Usage Calculator — it works out gasket area, total material and sheet count including realistic cutting wastage.
Can you cut gaskets to my drawing?
Yes. Send us a drawing, a template or the flange dimensions and we will cut them for you.
Are all non-asbestos jointing sheets the same?
No, and this is worth being careful about. It is a material family, not a single specification — grades differ substantially in temperature ceiling, pressure rating and creep behaviour, and they look identical. Compare the actual ASTM figures, not the description.
How should I store it?
Flat, dry, out of sunlight and away from oils and heat. Do not store it rolled or leaning, as it will take a bow that makes accurate cutting difficult.
What is the shelf life?
Long and stable if stored flat and dry. The binder can harden over many years in poor storage conditions, but correctly stored sheet remains usable for a long time.
Need a quote or a spec check?
Send us your operating conditions and we will confirm the right grade for the job.
