WHAT IS

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WHAT IS MASTITE NON-ASBESTOS ?
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MASTITE NON-ASBESTOS ARE MATERIALS THAT HAVE
BEEN SPECIALLY DEVELOPED TO COMBAT THE DANGERS
OF ASBESTOSIS
WHAT IS MASTITE NON-ASBESTOS ?
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PLEASE LET ME INTRODUCE MYSELF MY NAME IS MR.
MASTITE I WILL BE TALKING TO YOU ABOUT HEALTH
SAFETY ASBESTOS V NON-ASBESTOS MATERIAL
PROPERTIES
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DID YOU KNOW
FOR MORE THAN 20 YEARS IT HAS BEEN
KNOWN ASBESTOS CAN SERIOUSLY DAMAGE YOUR HEALTH
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DID YOU KNOW
IT IS ESTIMATED 3,500 PEOPLE DIE EACH YEAR FROM
ASBESTOSIS
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ALSO
BY THE YEAR 2000 ALL ASBESTOS WILL BE
PROHIBITED IN EUROPE AMERICA
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AND
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WHAT ARE THE DIFFERENCES BETWEEN ASBESTOS AND
NON-ASBESTOS
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WHAT ARE THE DIFFERENCES BETWEEN ASBESTOS AND
NON-ASBESTOS
GOOD QUESTION
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ASBESTOS NON-
ASBESTOS TEMPERATURE approx.500
apprx.300 FIBRE CONTENT up to 70 up
to 40 COMPRESSION approx.10 approx.
15 SAFETY DANGEROUS safer
alternative COST
appox. X 2
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Non-Asbestos There is no one fibre that can
replace the asbestos fibre at present.
Most manufacturers use a combination of Aramid,
Glass, Mineral and Carbon. It is also know that
there are many more compositions used when
producing Non-asbestos sheeting than when
producing asbestos.
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WHAT PROPERTIES MAKE A GOOD SEAL ?
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TYPICAL FLANGE JOINT
Sealing Properties required Good
compression Low creep Temperature
resistance Chemical resistance Low
permeability Recovery
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K.M.G. ????????
FLANGE JOINT SECTION
External Pressure (Bolt Torque )
IDEAL GASKET High Compressibility with a low
creep factor giving good resistance to
temperature chemicals/gases. It is always
better to have the thinnest gasket
possible however consideration of flange
smoothness distortion should be made when
calculating the Gasket thickness.
Internal Pressure. Resistance to Fluid or Gas
being handled.
Resilience to Flange Movement
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POSSIBLE LEAK PATHS
Permeability through the Material
Irregularities of the Flange surface
flange distortion. Giving rise to
possible leakage
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GUIDE TO CALCULATING GASKET THICKNESS
X Times 2 x 100 y
Gasket Thickness
Measure surface finish flange distortion. Take
the greater of the two x
ASBESTOS Typical compression value of
Asbestos 9y
NON-ASBESTOS Typical compression value of
Non-Asbestos 13y
Eg. Asbestos 0.135 x 2 x100 y(9)
3mm
Eg. Non-Asbestos 0.135 x 2 x100 y(13)
2mm
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GASKET CREEP
External Pressure (Bolt Torque )
Gasket creep occurs when external
stress(pressure) and temperature is applied to
the gasket. The effect of gasket creep is a
thickness decrease in the gasket material
coupled with the gasket spreading into the inner
flange the outer. In extreme cases
gasket creep can result in a complete breakdown
of the material.
External Pressure (Bolt Torque )
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GASKET CREEP
External Pressure (Bolt Torque )
Gasket creep occurs when external
stress(pressure) and temperature is applied to
the gasket. The effect of gasket creep is a
thickness decrease in the gasket material
coupled with the gasket spreading into the inner
flange the outer. In extreme cases
gasket creep can result in a complete breakdown
of the material.
External Pressure temperature cause gasket
thickness decrease creep
External Pressure (Bolt Torque )
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GASKET CREEP
External Pressure (Bolt Torque )
Gasket creep occurs when external
stress(pressure) and temperature is applied to
the gasket. The effect of gasket creep is a
thickness decrease in the gasket material
coupled with the gasket spreading into the inner
flange the outer. In extreme cases
gasket creep can result in a complete breakdown
of the material.
This then reduces the external downward
pressure creating potential leak paths
External Pressure (Bolt Torque )
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GASKET CREEP
Generally the higher the compressibility of a
material the better the initial
sealing properties. However high
compressibility can sometimes give high levels of
GASKET CREEP which will cause the gasket to leak
or in some cases fail completely. So far we can
conclude that material with good
compressibility and low creep is desirable.
GOOD COMPRESSIBILITY LOW CREEP GOOD
SEALABILITY
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GASKET RECOVERY
External Pressure
Gasket Recovery is very important when the
material is under cyclic loading. For example
when a flange is heated expansion occurs causing
increased pressure on the gasket resulting in
the gasket reducing in thickness. When the
loading (pressure) is reduced the gasket
should recover its thickness sufficiently enough
as to not impair its sealing abilities.
External Pressure
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GASKET RECOVERY
Increased External Pressure
Gasket Recovery is very important when the
material is under cyclic loading. For example
when a flange is heated expansion occurs causing
increased pressure on the gasket resulting in
the gasket reducing in thickness. When the
loading (pressure) is reduced the gasket
should recover its thickness sufficiently enough
as to not impair its sealing abilities.
The flange expands causing increased pressure on
the gasket
Increased External Pressure
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GASKET RECOVERY
External Pressure
Gasket Recovery is very important when the
material is under cyclic loading. For example
when a flange is heated expansion occurs causing
increased pressure on the gasket resulting in
the gasket reducing in thickness. When the
loading (pressure) is reduced the gasket
should recover its thickness sufficiently enough
as to not impair its sealing abilities.
Gasket recovery
External Pressure
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HOT CREEP TEST
STANDARD DIN 28090-1 (Modified)
MATERIAL MASTITE NASB 9 2.0mm
NON-ASBESTOS TEST 5 HOUR HOT CREEP
_at_ 50MPa 300? C RESULT 8.5 CREEP 22
COLD COMPRESSION
TEMPERATURE C
THICKNESS DECREASE mm
30 60 90
120 150
180 210
240 270 300
TOTAL TIME 5 HOURS ( SEGMENTS 30 MINUTES )
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HOT CREEP TEST
STANDARD DIN 28090-1 (Modified)
MATERIAL MASTITE NASB 9 2.0mm
NON-ASBESTOS TEST 5 HOUR HOT CREEP
_at_ 50MPa 300? C RESULT 8.5 CREEP 22
COLD COMPRESSION
TEMPERATURE C
THICKNESS DECREASE mm
30 60 90
120 150
180 210
240 270 300
TOTAL TIME 5 HOURS ( SEGMENTS 30 MINUTES )
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STANDARD DIN 28090-1 (Modified)
COLD COMPRESSION
MATERIAL MASTITE NASB 9 2.0mm
NON-ASBESTOS TEST 30 MINUTES COLD
COMPRESSION _at_ 50MP RESULT 8.5 CREEP 22
COLD COMPRESSION
TEMPERATURE C
THICKNESS DECREASE mm
Decrease in Material Thickness equals
0.44mm equals 22
30 mins
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CHECK LIST
Remember !! Reduce thickness when using non -
asbestos
1) What temperature is required ? 2) What
internal/external pressure ? 3) Flange
irregularities ? Decide on compressibility
thickness of material 4) Does the material have
a low creep value ? 5) Is the material resistant
to the medium being sealed? 6) Will the
gasket be under cyclic loading ? Check stress
relaxation recovery
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FINALLY
Mr Mastite