16
The IS 2712 Certified Gaskets How well do you know your Gasket Quality?
| Date post: | 22-Jan-2018 |
| Category: |
Engineering |
| Upload: | pge-india-pilot-gaskets |
| View: | 168 times |
| Download: | 1 times |
The IS 2712 Certified GasketsHow well do you know your Gasket Quality?
Overview of IS 2712
The Indian Standard IS 2712 is for Compressed Asbestos Fiber Jointing Sheet
The IS 2712 divides Gaskets into 5 Categories1. W/1: High Service Conditions2. W/2: Medium Service Conditions3. W/3: Low Service Conditions4. O/1: Oil- High Service Conditions5. A/1: Acids- Highly Corrosive
The Testing Parameters used are
A copy of the Indian Standard can be downloaded from the link: Indian Standard IS 2712:1998
1. Conditioning 2. Dimension 3. Density 4. Flexibility
5. Compressibility & Recovery 6. Stress Relaxation 7. Oil Absorption (For O/1) 8. Water Absorption
9. Acid Resistance (for A/1) 10. Tensile Strength 11. Loss of Ignition
Important Points of the IS 2712
Point 1.1. on Page no. 1 states “Wire Reinforced Material CANNOT be Indian Standard IS 2712 Certified. Hence no manufacturer will claim a Wire Reinforced Material is 2712 Compliant.
While a Manufacturer mention Max Temp: 50 Deg C and Max Pressure: 180 Bar on their brochure, the Gasket is actually certified only upto 510 Deg C and Pressure of 64 BarHence a Gasket is rated to only handle 510 Deg C at 64 Bar. Since the word Up To or Maximum is considered, this doesn’t mean Continuous.
Point 8.5.1 & 8.6.1 clearly mention that testing is done on 1.5mm ThkSample and not on a 3mm or a 5mm Sample. Hence a Gasket of a 3mm or 5mm will NOT have the same performance as 1.5mm but will be even worse since surface area exposed to the Medium has doubled.
Important Points of the IS 2712The pH of the Medium needs to be considered for Gasket selection. The action of Fluid at different Temperature and Pressure needs to be considered.
Gasket Sheets must be supplied Flat Sheets and not in Rolls. A rolled Sheet takes the curved sheet and cannot be straightened back flat. A Gasket cut from such a Sheet will also have a curve.
The Graphite Coating or Black Coating is only to prevent adhesion to the Flange Faces
The W/3 Low Service GasketHas to handle a maximum of 250 Deg C (No time limit defined) and 20 Bar Pressure (No time limit defined)
1. Conditioning: Kept in Oven for 100 Deg C for one hour and cooled to 27 Deg C
6. Stress Relaxation No Stress Clause for W/3
2. Dimension Dimension of higher thk has higher tolerance. 8. Water Absorption No Water Test
3. Density 1.7 g/cm3 to 2.2 g/cm3 10. Tensile Strength Greater than 6.7MPa
4. Flexibility Kept in an Oven for 70 Deg C for 168hours cooled to Room Temp, bend at 180 Deg C on Mandrel equal to 12x Times Thk of Sheet or 1.5mm X 12 = 18mm DiaNo Cracking
11. Loss of Ignition Max 28%
5. Compressibility & Recovery
At Room Temp, Stress of 1kN or 0.01Bar for 15secs, Stress of 15.6 kN or 0.15Bar.Comp: Between 5% to 14%. Recovery Greater than 40%
All the below testing parameters tested on 1.5mm Thk. Higher Thickness will have poor results. Metallic Reinforcement Gaskets are NOT IS Standard certified and will show poor performance in the below tests
The W/2 Medium Service GasketHas to handle a maximum of 350 Deg C (No time limit defined) and 40 Bar Pressure (No time limit defined)
1. Conditioning: Kept in Oven for 100 Deg C for one hour and cooled to 27 Deg C
6. Stress Relaxation 50Mpa 16 hr 300 Deg C>17.5MPa (Greater Than)
2. Dimension Dimension of higher thk has higher tolerance. 8. Water Absorption < 10% (Less than)
3. Density 1.7 g/cm3 to 2.2 g/cm3 10. Tensile Strength 0.4mm to 1mm > 9 Mpa1mm to 1.5mm > 12.8Mpa
4. Flexibility Kept in an Oven for 70 Deg C for 168hours cooled to Room Temp, bend at 180 Deg C on Mandrel equal to 12x Times Thk of Sheet or 1.5mm X 12 = 18mm DiaNo Cracking
11. Loss of Ignition Max 28%
5. Compressibility & Recovery
At Room Temp, Stress of 1kN or 0.01Bar for 15secs, Stress of 15.6 kN or 0.15BarComp: Between 5% to 14%. Recovery Greater than 40%
All the below testing parameters tested on 1.5mm Thk. Higher Thickness will have poor results. Metallic Reinforcement Gaskets are NOT IS Standard certified and will show poor performance in the below tests
The W/1 High Service GasketHas to handle a maximum of 510 Deg C (No time limit defined) and 64 Bar Pressure (No time limit defined)
1. Conditioning: Kept in Oven for 100 Deg C for one hour and cooled to 27 Deg C.
6. Stress Relaxation 50Mpa 16 hr 300 Deg C>23 Mpa (Greater Than)
2. Dimension Dimension of higher thk has higher tolerance. 8. Water Absorption < 10% (Less than)
3. Density 1.7 g/cm3 to 2.2 g/cm3 10. Tensile Strength 0.4mm to 1mm > 18 Mpa1mm to 1.5mm > 24Mpa
4. Flexibility Kept in an Oven for 70 Deg C for 168hours cooled to Room Temp, bend at 180 Deg C on Mandrel equal to 12x Times Thk of Sheet or 1.5mm X 12 = 18mm DiaNo Cracking
11. Loss of Ignition Max 28%
5. Compressibility & Recovery
At Room Temp, Stress of 1kN or 0.01Bar for 15secs, Stress of 15.6 kN or 0.15BarComp: Between 5% to 14%. Recovery Greater than 40%
All the below testing parameters tested on 1.5mm Thk. Higher Thickness will have poor results. Metallic Reinforcement Gaskets are NOT IS Standard certified and will show poor performance in the below tests
The O/1 Oil Service GasketNo Temperature or Pressure Specification mentioned.
1. Conditioning: Kept in Oven for 100 Deg C for one hour and cooled to 27 Deg C
6. Stress Relaxation 50Mpa 16 hr 300 Deg C>23 Mpa (Greater Than)
2. Dimension Dimension of higher thk has higher tolerance. 7. Oil Absorption Thk increase < 25 Deg in Oil for 5hrs at 150 Deg C. Lesser the better.
3. Density 1.7 g/cm3 to 2.2 g/cm3 8. Water Absorption < 10% (Less than)
4. Flexibility Kept in an Oven for 70 Deg C for 168hours cooled to Room Temp, bend at 180 Deg C on Mandrel equal to 12x Times Thk of Sheet or 1.5mm X 12 = 18mm DiaNo Cracking
10. Tensile Strength 0.4mm to 1mm – >18 Mpa1mm to 1.5mm- >24Mpa
5. Compressibility& Recovery
At Room Temp, Stress of 1kN or 0.01Bar for 15secs, Stress of 15.6 kN or 0.15BarComp: Between 5% to 14%. Recovery Greater than 40%
11. Loss of Ignition Max 28%
All the below testing parameters tested on 1.5mm Thk. Higher Thickness will have poor results. Metallic Reinforcement Gaskets are NOT IS Standard certified and will show poor performance in the below tests
The A/1 Acid Service GasketNo Temperature or Pressure Specification mentioned.
1. Conditioning: Kept in Oven for 100 Deg C for one hour and cooled to 27 DegC
6. Stress Relaxation 50Mpa 16 hr 300 Deg C>23 Mpa (Greater Than)
2. Dimension Dimension of higher thk has higher tolerance. 9. Acid Resistance Swell (checks absorption) Thk Increase: Nitric Acid: 50% Strength 1 Hr @ 65 Deg: <12% Nitric Acid: 95% Strength 18 Hr @ Room: <20%Sulphuric Acid: 96% Strength 18 Hr @ Room: <8%Sulphuric Acid: 65% Strength 48 Hr @ Room: <20%
3. Density 1.7 g/cm3 to 2.2 g/cm3 8. Water Absorption < 10% (Less than)
4. Flexibility Kept in an Oven for 70 Deg C for 168hours cooled to Room Temp, bend at 180 Deg C on Mandrel equal to 12x Times Thkof Sheet or 1.5mm X 12 = 18mm DiaNo Cracking
10. Tensile Strength 0.4mm to 1mm – >18 Mpa1mm to 1.5mm- >24Mpa
5. Compressibility& Recovery
At Room Temp, Stress of 1kN or 0.01Bar for 15secs, Stress of 15.6 kN or 0.15BarComp: Between 5% to 14%. Recovery Greater than 40%
11. Loss of Ignition Max 28%
All the below testing parameters tested on 1.5mm Thk. Higher Thickness will have poor results. Metallic Reinforcement Gaskets are NOT IS Standard certified and will show poor performance in the below tests
Why the IS 2712 is now obsolete?1. Maximum Temperature standard is defined without a Time constraint making it irrelevant
2. Maximum Pressure standard is defined without a Time constraint making it irrelevant
3. Temperature and Pressure in a Gasket are inverse, that means a W/1 Gasket might handle higher pressure (100Bar) at Room Temperature and a W/1 Gasket will handle higher temperature (550 Deg CC) at Lower Pressure (20 Bar).
4. None of the Testing Standard actually test for Temperature Resistivity or Maximum Constraint.
5. None of the Testing Standard actually test for Pressure Resistivity or Maximum Constraint.
6. All of the testing is done on 1.5mm thk Gasket. Lower Thickness Gasket perform far better than Higher Thickness.
7. METALLIC Reinforcement actually reduces the performance of the Gasket. Graphite Coating is required to ensure removal of the Gasket and Metal Gauge from the Flange.
8. Compressibility and Recovery taken on different points are irrelevant on room Temperature. Recovery is a percentage of Compressibility and it is possible to have an incorrect performance parameter due to this.
9. Asbestos is carcinogenic and Cutting of Gaskets or Removal of Old Gaskets release dust.
10. Continuous Temperature & Continuous Pressure is not used to categorize Gaskets
11. pH of the Medium is not considered at all.
Why the IS 2712 is now irrelevant?• 3mm Gasket is more expensive than a 1.5mm Gasket. But a 3mm Gasket performs poorly compared to a
1.5mm Gasket
• Metallic Reinforced Gasket is more expensive than a non-metallic one. But a Metallic Gasket performs poorly compared to a non-Metallic one.
• A CAF Gasket comprises of Asbestos (70% to 90%), Elastomer (10% to 20%) Fillers (10% to 20%) & Chemicals (1% to 2%). Hence all the heavy workload was done by Asbestos. A Gasket starts performing based on the Asbestos Content.
• The Metal Wire Gauge added to the Gasket might make it seem the Gasket is performing better but it is an illusion.
• Frequent Gasket Replacement is good for Manufacturer.
• The Graphite Coating gives a poor anti-stick performance. CAF have Chlorine Binders leading to corrosion.
• The Max Temperature and Max Pressure Specification is dependent upon the Manufacturer’s Moral standards and Ethics.
• The 1.5mm Testing Sample sent for IS Specification needs to be of the Same Equivalent value and is upon the Manufacturer’s Moral Standards and Ethics.
For W/3 & W/2 ApplicationsTest For W/3 For W/2 DONIT BA 101/102
Density 1.7 g/cm3 to 2.2 g/cm3 1.8
Compressibility 5% to 14% 8%
Recovery Greater than 40% 57%
Stress Resistance NOT Tested >17.5 18%
Oil Resistance NOT Tested NOT Tested 13%
Max Temp 250 Deg C for 1 Sec 350 Deg C for 1 Sec
350 for 1 Sec
Pressure 20 Bar 40 Bar 40 Bar
Material ASBESTOS ASBESTOS nonAsbestos
Thk Tested 1.5mm Thk 1.5mm Thk 2mm
Higher the Thickness, Poorer are the above values. Metallic Reinforcement is not IS Certified.
For W/1 High ServiceTest For W/1 DONIT BA 203 DONIT BA 50 DONIT BA 55 BA GL SPECTRUM GRAFILIT SL
Density 1.7 g/cm3 to 2.2 g/cm3 1.8 1.8 1.8 1.8 1.4 1.3
Compressibility 5% to 14% 10% 9% 7% 7% 25% 42%
Recovery Greater than 40% 60% 55% 55% 55% >25% 15%
Stress Resistance >23 25% 25% 30% 33% 40% 49%
Oil Resistance NOT Tested 8% 8% 8% 3% 7% NOT Tested
Max Temp 510 Deg C for 1 Sec 450 for 1 Sec200 Cont.
450 for 1 Sec220 Cont.
450 for 1 Sec270 Cont.
650 for 30 Mins350 Cont.
900 Deg for 30 mins400 Deg Cont.
900 Deg for 30 mins
600 Deg Cont.
Pressure 60 Bar 50 Bar 80 Bar 100 Bar 120 Bar 100 Bar 100 Bar
Material ASBESTOS nonAsbestos nonAsbestos nonAsbestos nonAsbestos Carbon Graphite
Thk Tested 1.5mm Thk 2mm 2mm 2mm 2mm 2mm 2mm
Higher the Thickness, Poorer are the above values. Metallic Reinforcement is not IS Certified.
For O/1 Oil High Service
Test For O/1 DONIT BA 203 DONIT BA 50 DONIT BA 55 BA U BA GL
Density 1.7 g/cm3 to 2.2 g/cm3
1.8 1.8 1.8 1.7 1.8
Compressibility 5% to 14% 10% 9% 7% 11% 7%
Recovery Greater than 40% 60% 55% 55% 60% 55%
Stress Resistance >23 25% 25% 30% 23% 33%
Oil Resistance Thk increase < 25 Deg in Oil for 5hrs at
150 Deg C.
8% 8% 8% 2% 3%
Max Temp 510 Deg C for 1 Sec 450 for 1 Sec200 Cont.
450 for 1 Sec220 Cont.
450 for 1 Sec270 Cont.
500 for 1 Sec250 Cont.
650 for 30 Mins350 Cont.
Pressure 60 Bar 50 Bar 80 Bar 100 Bar 120 Bar 120 Bar
Material ASBESTOS nonAsbestos nonAsbestos nonAsbestos nonAsbestos nonAsbestos
Thk Tested 1.5mm Thk 2mm 2mm 2mm 2mm 2mm
Higher the Thickness, Poorer are the above values. Metallic Reinforcement is not IS Certified.
The Change Ahead• Ensure Technical Specs have your application details rather than Manufacturers Specs. For Material
Selection mention performance parameters. Incorporate a Temp/Pressure tests to ensure Quality. Your specs should have
• Your Continuous Design Temp
• Your Continuous Design Pressure
• Medium Gasket in Contact with (pH)
• Application of the Equipment
• Size. (Preferred Thk is 2mm or 1.5mm)
• If your Flanges and Joints are as per ASME/ DIN standard, procure ready cut Gaskets wherever possible with minimal Sheets in stock for emergency. Ready Cut take up less space, are practical and economical.
• Do not procure Sheets in Kilograms. Your consumption unit is going to be Surface Area since you are going to cut shapes from the Sheet. The Weight of the Sheet is immaterial or inconsequential to you. Different Fibers have different Weight but Consumption of Sq Mtrs is always going to be consistent and is your cost centre.
• Since majority of Gaskets are circular, the ideal Size of a Sheet should be a Square to ensure minimal Wastage at your end. A 1500mm X 1500mm Size is ideal.
Thank YouContact us for your Technical Solution to your Sealing requirements
Ph: +91 8080890022
W: www.pilotgaskets.com
