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WHAT IS MASTITE NON-ASBESTOS ?. MASTITE NON-ASBESTOS ARE MATERIALS THAT HAVE BEEN SPECIALLY DEVELOPED TO COMBAT THE DANGERS OF ASBESTOSIS. WHAT IS MASTITE NON-ASBESTOS ?. PLEASE LET ME INTRODUCE MYSELF MY NAME IS MR. MASTITE I WILL BE TALKING TO YOU ABOUT: HEALTH & SAFETY
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WHAT IS MASTITE NON-ASBESTOS ?
MASTITE NON-ASBESTOS ARE MATERIALS THAT HAVE BEEN SPECIALLY DEVELOPED TO COMBAT THE DANGERS OF ASBESTOSIS WHAT IS MASTITE NON-ASBESTOS ?
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
DID YOU KNOW FOR MORE THAN 20 YEARS IT HAS BEEN KNOWN ASBESTOS CAN SERIOUSLY DAMAGE YOUR HEALTH
DID YOU KNOW IT IS ESTIMATED 3,500 PEOPLE DIE EACH YEAR FROM ASBESTOSIS
ALSO BY THE YEAR 2000 ALL ASBESTOS WILL BE PROHIBITED IN EUROPE & AMERICA
WHAT ARE THE DIFFERENCES BETWEEN ASBESTOS AND NON-ASBESTOS
WHAT ARE THE DIFFERENCES BETWEEN ASBESTOS AND NON-ASBESTOS GOOD QUESTION
ASBESTOSNON- ASBESTOS TEMPERATURE:approx.500 apprx.300 FIBRE CONTENT up to 70% up to 40% COMPRESSION approx.10% approx. 15% SAFETY DANGEROUSsafer alternative COST appox. X 2
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.
WHAT PROPERTIES MAKE A GOOD SEAL ?
TYPICAL FLANGE JOINT Sealing Properties required : Good compression Low creep Temperature resistance Chemical resistance Low permeability Recovery
K.M.G. 한국매스타이트㈜ 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
POSSIBLE LEAK PATHS Permeability through the Material Irregularities of the Flange surface & flange distortion. Giving rise to possible leakage
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 9%=y NON-ASBESTOS Typical compression value of Non-Asbestos 13%=y Eg. Asbestos 0.135 x 2 x100 y(9) 3mm Eg. Non-Asbestos 0.135 x 2 x100 y(13) 2mm
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 )
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 )
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 )
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
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
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
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
HOT CREEP TEST STANDARD: DIN 28090-1 (Modified) MATERIAL : MASTITE NASB 9 2.0mm NON-ASBESTOS TEST : 5 HOUR HOT CREEP @ 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 )
HOT CREEP TEST STANDARD: DIN 28090-1 (Modified) MATERIAL : MASTITE NASB 9 2.0mm NON-ASBESTOS TEST : 5 HOUR HOT CREEP @ 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 )
STANDARD: DIN 28090-1 (Modified) COLD COMPRESSION MATERIAL : MASTITE NASB 9 2.0mm NON-ASBESTOS TEST : 30 MINUTES COLD COMPRESSION @ 50MP RESULT : 8.5% CREEP 22% COLD COMPRESSION TEMPERATURE °C THICKNESS DECREASE mm Decrease in Material Thickness equals 0.44mm equals 22% 30 mins
CHECKLIST 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
FINALLY Mr Mastite