Dear Sir
Thanks for your prompt reply and first of all sorry for a late reply...
The question - Which fuel gas (DA or LPG) is more SAFE to use for gas cutting operation and Why? - is also was a very debating one for me. I have discussed with few people with mechanical background... Get different answers... Few was telling, DA and few was saying LPG... When I put the explanations I got from your side in front of those who said DA is safe, they were seems satisfied... Thanks for giving valuable reply sir...
Now let me try to answer your question:
1. How an acetylene cylinder is constructed - Please refer attachement.
2. Why acetylene should not be laid horizontally?
To prevent loss of acetone which reduces the cylinder’s ability to hold dissolved acetylene. Hence always store and use acetylene cylinders in an upright position.
Also we must suggest to keep all gas cylinders in vertical position to avoid the passage of liquid stage gas flow to the hose pipes, which can damage the hose pipe, not only in Acetylene.
If any points mentioned is not right please make me clear.
@ TS
You are right, he was there with his valuable help always...
Regards,
Dipil Kumar V
From India
713Thanks for your prompt reply and first of all sorry for a late reply...
The question - Which fuel gas (DA or LPG) is more SAFE to use for gas cutting operation and Why? - is also was a very debating one for me. I have discussed with few people with mechanical background... Get different answers... Few was telling, DA and few was saying LPG... When I put the explanations I got from your side in front of those who said DA is safe, they were seems satisfied... Thanks for giving valuable reply sir...
Now let me try to answer your question:
1. How an acetylene cylinder is constructed - Please refer attachement.
2. Why acetylene should not be laid horizontally?
To prevent loss of acetone which reduces the cylinder’s ability to hold dissolved acetylene. Hence always store and use acetylene cylinders in an upright position.
Also we must suggest to keep all gas cylinders in vertical position to avoid the passage of liquid stage gas flow to the hose pipes, which can damage the hose pipe, not only in Acetylene.
If any points mentioned is not right please make me clear.
@ TS
You are right, he was there with his valuable help always...
Regards,
Dipil Kumar V
From India
Dear Dipil,
You know the reasons, but many including the mechanical engineers at site may not be aware of the problem with handling acetylene cylinders i horizontally. You can see the cylinders being handled dangerously, often laid horizontally in vehicles. We had in the past very many accidents from unsafe handling of these cylinders. We may have to watch for ensuring that acetylene is handled safely.
(One more point: seeing your attachment I just remembered Hanuman going to Maruthuwa hills for Mruthasanjeevini.)
We in safety need specific points - let the literature go to students for them to digest well.
Regards,
Kesava Pillai
From India, Kollam
You know the reasons, but many including the mechanical engineers at site may not be aware of the problem with handling acetylene cylinders i horizontally. You can see the cylinders being handled dangerously, often laid horizontally in vehicles. We had in the past very many accidents from unsafe handling of these cylinders. We may have to watch for ensuring that acetylene is handled safely.
(One more point: seeing your attachment I just remembered Hanuman going to Maruthuwa hills for Mruthasanjeevini.)
We in safety need specific points - let the literature go to students for them to digest well.
Regards,
Kesava Pillai
From India, Kollam
Dear Sir
Thanks for your frank comment... The literature was from my study materil collections... Hence not think to modify more, just directly post... May be useful to anyone who interested...
Thanks for another useful discussion sir...
Regards,
Dipil Kumar V
From India
Thanks for your frank comment... The literature was from my study materil collections... Hence not think to modify more, just directly post... May be useful to anyone who interested...
Thanks for another useful discussion sir...
Regards,
Dipil Kumar V
From India
Hi all,,, As per my view, DA is more safer than LPG for gas cutting operation in industries.. I would suggest to have discussion on the same to have more clarification.
From India, Mumbai
From India, Mumbai
Dear Krunalsheth
Thank you for your post.
For your opinion on ‘Acetylene being safer”- can you kindly try to substantiate it please?
In safety matters a safety man has to be firm. Here one’s opinion has no value.
1. Safety has to say “yes this is safe or this is not safe”; that too convincingly and communicate it for others to understand.
2. When one says an item is safer than other, naturally safety measures required in that safer item will be relaxed.
3. With Acetylene and LPG we are in a conflict situation “Avoidance = Avoidance” Just like devil and deep see.
4. I do not like spoon feeding. On seeing your comments I will give you the reasons "how your DA is more dangerous than LPG." LPG IS OF COURSE SAFER THAN ACETYLENE.
Let us continue till we are assured of the right thing.
Thanks again for participation for you are sure to gain with these discussions.
Regards,
Kesava Pillai
From India, Kollam
Thank you for your post.
For your opinion on ‘Acetylene being safer”- can you kindly try to substantiate it please?
In safety matters a safety man has to be firm. Here one’s opinion has no value.
1. Safety has to say “yes this is safe or this is not safe”; that too convincingly and communicate it for others to understand.
2. When one says an item is safer than other, naturally safety measures required in that safer item will be relaxed.
3. With Acetylene and LPG we are in a conflict situation “Avoidance = Avoidance” Just like devil and deep see.
4. I do not like spoon feeding. On seeing your comments I will give you the reasons "how your DA is more dangerous than LPG." LPG IS OF COURSE SAFER THAN ACETYLENE.
Let us continue till we are assured of the right thing.
Thanks again for participation for you are sure to gain with these discussions.
Regards,
Kesava Pillai
From India, Kollam
Dear Mr. Kesava,
In addition to your message,
we should not keep the cylinders in horizontal position becoz of its pressure. Since it is stored at high pressure & if there is a damage at the outlet (top), the pressure will be released towards open end, which inturn will force the other part (metal body) to flew in the other direction. (I have heard that it will fly like a rocket!!! is it true???)
In addition to this, I have some more details of Acetylene. Pls. find the same. Hope this would be useful.
Acetylene is the primary fuel for oxy-fuel welding and is the fuel of choice for repair work and general cutting and welding. Acetylene gas is shipped in special cylinders designed to keep the gas dissolved. The cylinders are packed with porous materials (e.g. kapok fiber, diatomaceous earth, or (formerly) asbestos), then filled to around 50% capacity with acetone, as acetylene is acetone soluble.
This method is necessary because above 207 kPa (30 lbf/in²) (absolute pressure) acetylene is unstable and may explode.
There is about 1700 kPa (250 psi) pressure in the tank when full. Acetylene when combined with oxygen burns at a temperature of 3200 °C to 3500 °C (5800 °F to 6300 °F), highest among commonly used gaseous fuels.
As fuel acetylene's primary disadvantage, in comparison to other fuels, is high cost.
As acetylene is unstable at a pressure roughly equivalent to 33 feet/10 meters underwater, water submerged cutting and welding is reserved for hydrogen rather than acetylene.
From India, Delhi
In addition to your message,
we should not keep the cylinders in horizontal position becoz of its pressure. Since it is stored at high pressure & if there is a damage at the outlet (top), the pressure will be released towards open end, which inturn will force the other part (metal body) to flew in the other direction. (I have heard that it will fly like a rocket!!! is it true???)
In addition to this, I have some more details of Acetylene. Pls. find the same. Hope this would be useful.
Acetylene is the primary fuel for oxy-fuel welding and is the fuel of choice for repair work and general cutting and welding. Acetylene gas is shipped in special cylinders designed to keep the gas dissolved. The cylinders are packed with porous materials (e.g. kapok fiber, diatomaceous earth, or (formerly) asbestos), then filled to around 50% capacity with acetone, as acetylene is acetone soluble.
This method is necessary because above 207 kPa (30 lbf/in²) (absolute pressure) acetylene is unstable and may explode.
There is about 1700 kPa (250 psi) pressure in the tank when full. Acetylene when combined with oxygen burns at a temperature of 3200 °C to 3500 °C (5800 °F to 6300 °F), highest among commonly used gaseous fuels.
As fuel acetylene's primary disadvantage, in comparison to other fuels, is high cost.
As acetylene is unstable at a pressure roughly equivalent to 33 feet/10 meters underwater, water submerged cutting and welding is reserved for hydrogen rather than acetylene.
From India, Delhi
Mr.KVSundaram,
Thanks for your valuable contribution.
On the primary question as to which is comparatively safer - "Acetylene or LPG" few of our friends in the forum are doubtful.
Before I provide the exact reasons for LPG being comparatively safer than Acetylene I want to know what is the general approach among the youngesters and I am still waiting for a few more posts on this pl.
Regards,
Kesava Pillai
From India, Kollam
Thanks for your valuable contribution.
On the primary question as to which is comparatively safer - "Acetylene or LPG" few of our friends in the forum are doubtful.
Before I provide the exact reasons for LPG being comparatively safer than Acetylene I want to know what is the general approach among the youngesters and I am still waiting for a few more posts on this pl.
Regards,
Kesava Pillai
From India, Kollam
Dear Mr. Kesava,
Thank you for your reply. On an anxious mood I replied & felt guilty on seeing your reply.
However I'm providing some details about both.
Use of LPG is compartively safer than that of Acetylene, becoz of its properties & handling temparature.
While comparing the Explosive limits, the LEL & UEL of LPG is 1.9% to 9.5% nly, whereas Acetylene has a wide range of 2.5% to 80%.
Also, I have some independent data for Acetylene & LPG. I'm not so sure, whether it relates to our discussion, wehreas atleast some can get more idea between Acetylene & LPG.
Acetylene
Approximately 20 percent of acetylene is consumed for oxyacetylene gas welding and cutting due to the high temperature of the flame; combustion of acetylene with oxygen produces a flame of over 3600 K (3300 °C, 6000 °F), releasing 11.8 kJ/g. Oxyacetylene is the hottest burning common fuel gas. Acetylene is the third hottest natural chemical flame after cyanogens at 4798 K (4525 °C, 8180 °F) and dicyanoacetylene's 5260 K (4990 °C, 9010 °F). Oxy-acetylene welding was a very popular welding process in previous decades; however, the development and advantages of arc-based welding processes have made oxy-fuel welding nearly extinct for many applications. Acetylene usage for welding has dropped significantly. On the other hand, oxy-acetylene welding equipment is quite versatile – not only because the torch is preferred for some sorts of iron or steel welding (as in certain artistic applications), but also because it lends itself easily to brazing, braze-welding, metal heating (for annealing or tempering, bending or forming), the loosening of corroded nuts and bolts, and other applications. Oxyacetylene welding may also be used in areas where electricity is not readily accessible. As well, oxy-fuel cutting is still very popular and oxy-acetylene cutting is utilized in nearly every metal fabrication shop. For use in welding and cutting, the working pressures must be controlled by a regulator, since above 15 psi acetylene will decompose explosively.
LPG (mixture of Butane & Propane)
Butane, like propane, is a saturated hydrocarbon. Butane and propane do not react with each other and are regularly mixed together. Butane boils at 0.6 deg C. Propane is more volatile, with a boiling point of - 42 deg C. Vaporization is rapid at temperatures above the boiling points. The calorific (heat) values of both are almost equal. Both are thus mixed together to attain the vapor pressure that is required by the end user and depending on the ambient conditions. If the ambient temperature is very low propane is preferred to achieve higher vapor pressure at the given temperature.
Propane does not burn as hot as acetylene in its inner cone, and so it is rarely used for welding. Propane, however, has a very high number of BTUs per cubic foot in its outer cone, and so with the right torch can make a faster and cleaner cut than acetylene, and is much more useful for heating and bending than acetylene.
Propane is cheaper than acetylene and easier to transport.
Like propylene, most propane tips are of a two piece design. Propane often gets unfair criticism because it really needs changing your torch (from an equal pressure torch to an injector torch) and not just changing your tip to get the best performance. Most torches are equal pressure and designed for gases such as acetylene which are lighter than oxygen. Propane is a great deal heavier and runs much better through a low-pressure injector torch with a setting from a few ounces to about two pounds per square inch when cutting.
Hope you find it useful. If it is not related to this thread, kindly regret.
Thanks & regards
From India, Delhi
Thank you for your reply. On an anxious mood I replied & felt guilty on seeing your reply.
However I'm providing some details about both.
Use of LPG is compartively safer than that of Acetylene, becoz of its properties & handling temparature.
While comparing the Explosive limits, the LEL & UEL of LPG is 1.9% to 9.5% nly, whereas Acetylene has a wide range of 2.5% to 80%.
Also, I have some independent data for Acetylene & LPG. I'm not so sure, whether it relates to our discussion, wehreas atleast some can get more idea between Acetylene & LPG.
Acetylene
Approximately 20 percent of acetylene is consumed for oxyacetylene gas welding and cutting due to the high temperature of the flame; combustion of acetylene with oxygen produces a flame of over 3600 K (3300 °C, 6000 °F), releasing 11.8 kJ/g. Oxyacetylene is the hottest burning common fuel gas. Acetylene is the third hottest natural chemical flame after cyanogens at 4798 K (4525 °C, 8180 °F) and dicyanoacetylene's 5260 K (4990 °C, 9010 °F). Oxy-acetylene welding was a very popular welding process in previous decades; however, the development and advantages of arc-based welding processes have made oxy-fuel welding nearly extinct for many applications. Acetylene usage for welding has dropped significantly. On the other hand, oxy-acetylene welding equipment is quite versatile – not only because the torch is preferred for some sorts of iron or steel welding (as in certain artistic applications), but also because it lends itself easily to brazing, braze-welding, metal heating (for annealing or tempering, bending or forming), the loosening of corroded nuts and bolts, and other applications. Oxyacetylene welding may also be used in areas where electricity is not readily accessible. As well, oxy-fuel cutting is still very popular and oxy-acetylene cutting is utilized in nearly every metal fabrication shop. For use in welding and cutting, the working pressures must be controlled by a regulator, since above 15 psi acetylene will decompose explosively.
LPG (mixture of Butane & Propane)
Butane, like propane, is a saturated hydrocarbon. Butane and propane do not react with each other and are regularly mixed together. Butane boils at 0.6 deg C. Propane is more volatile, with a boiling point of - 42 deg C. Vaporization is rapid at temperatures above the boiling points. The calorific (heat) values of both are almost equal. Both are thus mixed together to attain the vapor pressure that is required by the end user and depending on the ambient conditions. If the ambient temperature is very low propane is preferred to achieve higher vapor pressure at the given temperature.
Propane does not burn as hot as acetylene in its inner cone, and so it is rarely used for welding. Propane, however, has a very high number of BTUs per cubic foot in its outer cone, and so with the right torch can make a faster and cleaner cut than acetylene, and is much more useful for heating and bending than acetylene.
Propane is cheaper than acetylene and easier to transport.
Like propylene, most propane tips are of a two piece design. Propane often gets unfair criticism because it really needs changing your torch (from an equal pressure torch to an injector torch) and not just changing your tip to get the best performance. Most torches are equal pressure and designed for gases such as acetylene which are lighter than oxygen. Propane is a great deal heavier and runs much better through a low-pressure injector torch with a setting from a few ounces to about two pounds per square inch when cutting.
Hope you find it useful. If it is not related to this thread, kindly regret.
Thanks & regards
From India, Delhi
Dear All
Good participation in the thread... Nice to see...
Let me tell you what was my experience with this debate... I ask the question which is more safer fuel gas to fresh pass out graduates as well as to those who is in the mechanical field for more than 15 years... The youngsters were not sure about that and fail to comment... All who in the mechanical line saying DA, but fail to give more clarifications...
Surely I am benedicted with the discussions and helps to make my concept clear... Thanks to all who participated with valuable posts...
Regards,
DIPIL
From India
Good participation in the thread... Nice to see...
Let me tell you what was my experience with this debate... I ask the question which is more safer fuel gas to fresh pass out graduates as well as to those who is in the mechanical field for more than 15 years... The youngsters were not sure about that and fail to comment... All who in the mechanical line saying DA, but fail to give more clarifications...
Surely I am benedicted with the discussions and helps to make my concept clear... Thanks to all who participated with valuable posts...
Regards,
DIPIL
From India
Dear friends,
There seems to be no more posts on this. Let us conclude !
Check the gases following Haz.Com procedures - as per NFPA on health, Fire, Reactivity etc. Do this first and if all elements are equal go for checking on LEL and UEL to find the widest range as presented by Mr.KVS. There are many other factors to go for but this is the easiest system we can adopt.
In this way you can acertain that LPG is safer than Acetylene.
Convincing details attached.
With this I am sure that the doubt is cleared.
Regards,
Kesava Pillai
From India, Kollam
There seems to be no more posts on this. Let us conclude !
Check the gases following Haz.Com procedures - as per NFPA on health, Fire, Reactivity etc. Do this first and if all elements are equal go for checking on LEL and UEL to find the widest range as presented by Mr.KVS. There are many other factors to go for but this is the easiest system we can adopt.
In this way you can acertain that LPG is safer than Acetylene.
Convincing details attached.
With this I am sure that the doubt is cleared.
Regards,
Kesava Pillai
From India, Kollam
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