Scared Silly
Contributor
Yeah, yer condom will not make any noise but there will certainly be some noise 9 months later if not earlier.
BTW there are very rigid standards for testing condoms: http://www.astm.org/Standards/D3492.htm
Overfilling and life expectancy. (LP Tanks)
- Thread starter p1p
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Yeah, yer condom will not make any noise but there will certainly be some noise 9 months later if not earlier.
BTW there are very rigid standards for testing condoms: http://www.astm.org/Standards/D3492.htm
irishsquid
Contributor
Nice!
ajduplessis
Contributor
Still living in your little box is see!
Almost all the cylinders we fail here are due to visuals. We fail very very few at hydro, steel or aluminum. Don't believe everything PSI says. They have their own agenda.
When they do fail hydro it is usually a side wall corrosion pit that gave way at pressure causing test pressure to drop and the readings to climb, or when the test pressure is released the cylinder residual (permanent expansion value) to exceed the allowable 10% for 3a, 3aa and 3al cylinders.
I have seen a cylinder which had exploded and it is a real event. One went off at a local gas supplier, just a 60 cf cylinder. It went across the street. Fortunately no one was around. It was not being filled, but just sitting in a skid of cylinders.
Dale
Engineered Inspection Systems, Inc. Home Page
The psi people have a lot of weird stuff in thier training. The very presentation of the material is full of agenda. TO THIER DEFENCE Thier goal is never an incident and if one happens it will not be the fault of the inspection process. I noticed that a lot of explosions referenced now were now more populated with steel tanks. I think to push the issue of overfillsand water bath filling. And that less of the aluminum incidents are occurring as the tanks are removed from service. Other things are the O2 cleaning requirements for 23% and above. At least they justify it from the partial preasure filling standpoint. Thier mention of pp filling for justification says to me that they agree with no o2 requirement below 40% but have to cover thier backside incase pp is used and results in the one rule to fit all. It is my understandng that they or the cga wanted all gas higher in o2 than air to be o2 clean required. the backed off to the 23.5% because some places in hte country the o2 levels are higher than 20.9 and all gas stations would then have to have o2 clean equipment to fill tires with.
To get back on topic: I prefer to look at science than to use regulation in learning what is safe and what is not. And then to use regulation in the application of that learned knowledge. I say that because centuries past taught us that same thing.. In the witch exicutions a suspected witch was held under water. Is she lived she was a witch if not she was inocent. I dont know of any witches that survived the drowning tests. And as suspected all the suspects proved in hindsight to be innocent.
So as far as science goes her is th info i have... Straight feom the PSI books and mixed with some logic.
TANK WALL THICKNESS STEEL : OF 3 MANUFACTUREERS FABER PST AND MORRIS. Faber has the thickest walls, pst the thinist. thicker walls hold more presure. bla bla bla. is the difference significant... i sont know the thinest for less than 100 cu ft is .164 and the thickest .185. cant seem like much but perhaps it is. greater than 100 cu ft the thinest is .179 asnd the thickest is .197. so big deal right.. not so quick. of the 4 tanks that are 100 or greater 2 of them are 2400# and the other 2 are 3500#. of less than 100's tha same os seen 2400# vs 3300#. It begs the question where does the strengh come from. Ther is a big difference in 2400 and 3500 for only .02 of inch wall thickness. Once again faber has the thickest. And the highest working psi is on the thinest walls. Seans to defy logic. What does hold true is the smaller the diameter the higher presure. that is 1 inch diffreence in the tank dia in the larger tanks. the < 100's is different there is only 3/10 " difference in the hp and lp tanks. so that seams to disprove it self. Some of those tanks are under SPermit, so perhaps the hp tanks are a deviaiton of the standard with out being suported by enhanced material. That suggests that perhaps the reason that 2400# is 2400# and not 3500# is the SP stamp on it. If that is so then lp's should be able to be safely pumped to hp levels. Now the tables in the PSI book show bouyancies of tanks also they are not what is seen on the web sights such as huron ect. for instance a lp95 without valve is +1 to -7. the american malve on it makes it -1to-9 and the european valve makes it get this -3 to -10. Why the difference i think it is back to the 2.5:1 safety favctor overseas and the 4:1 in the us. the overseas have heavy valves for the high presure. and by the way no blow out plugs.
I can guess that there is no answer other than the US is more cautious than overseas. Unfortunately the over caution (litigation????)gets turned into cya paronoia. and teh we all will die promoters.
From this i do see some bit of logic in the statements that many make when they say they will overfill lp tanks but not the hp's. Now that makes sence for the info i have in from of me. the data suggests that HP's are just LP's with hp working psi's stamped on them. One would be foolish to overfill already overfilled tanks.
Just my silver quaters worth, and after all there is no such thing as a silver quarter.....they all have copper in them. MUST BE COUNTERFIET.
To get back on topic: I prefer to look at science than to use regulation in learning what is safe and what is not. And then to use regulation in the application of that learned knowledge. I say that because centuries past taught us that same thing.. In the witch exicutions a suspected witch was held under water. Is she lived she was a witch if not she was inocent. I dont know of any witches that survived the drowning tests. And as suspected all the suspects proved in hindsight to be innocent.
So as far as science goes her is th info i have... Straight feom the PSI books and mixed with some logic.
TANK WALL THICKNESS STEEL : OF 3 MANUFACTUREERS FABER PST AND MORRIS. Faber has the thickest walls, pst the thinist. thicker walls hold more presure. bla bla bla. is the difference significant... i sont know the thinest for less than 100 cu ft is .164 and the thickest .185. cant seem like much but perhaps it is. greater than 100 cu ft the thinest is .179 asnd the thickest is .197. so big deal right.. not so quick. of the 4 tanks that are 100 or greater 2 of them are 2400# and the other 2 are 3500#. of less than 100's tha same os seen 2400# vs 3300#. It begs the question where does the strengh come from. Ther is a big difference in 2400 and 3500 for only .02 of inch wall thickness. Once again faber has the thickest. And the highest working psi is on the thinest walls. Seans to defy logic. What does hold true is the smaller the diameter the higher presure. that is 1 inch diffreence in the tank dia in the larger tanks. the < 100's is different there is only 3/10 " difference in the hp and lp tanks. so that seams to disprove it self. Some of those tanks are under SPermit, so perhaps the hp tanks are a deviaiton of the standard with out being suported by enhanced material. That suggests that perhaps the reason that 2400# is 2400# and not 3500# is the SP stamp on it. If that is so then lp's should be able to be safely pumped to hp levels. Now the tables in the PSI book show bouyancies of tanks also they are not what is seen on the web sights such as huron ect. for instance a lp95 without valve is +1 to -7. the american malve on it makes it -1to-9 and the european valve makes it get this -3 to -10. Why the difference i think it is back to the 2.5:1 safety favctor overseas and the 4:1 in the us. the overseas have heavy valves for the high presure. and by the way no blow out plugs.
I can guess that there is no answer other than the US is more cautious than overseas. Unfortunately the over caution (litigation????)gets turned into cya paronoia. and teh we all will die promoters.
From this i do see some bit of logic in the statements that many make when they say they will overfill lp tanks but not the hp's. Now that makes sence for the info i have in from of me. the data suggests that HP's are just LP's with hp working psi's stamped on them. One would be foolish to overfill already overfilled tanks.
Just my silver quaters worth, and after all there is no such thing as a silver quarter.....they all have copper in them. MUST BE COUNTERFIET.
Scared Silly
Contributor
KWS - I really do not see your point other than to perpetuate the myth that LP cylinders sold the USA are HP cylinders sold in Europe. Just cause two vessels are the same physical size does not in any shape or form mean they are the same. That myth has been debunked ad nauseum by folks like Lee at Sea Pearls.
If you want to talk science then do so with completeness. Material thickness is not the only variable that contributes to strength. There is material composition, annealing, etc. that all contribute.
If you want to talk science then do so with completeness. Material thickness is not the only variable that contributes to strength. There is material composition, annealing, etc. that all contribute.
VooDooGasMan
Contributor
Silly is right, the tanks are made different, PST had a great demo on how they make there tanks, can not speak for the rest of them.
Leadking
Contributor
KWS, you're so full of fertilizer and you don't even know it!
You seriously need to look at overseas hydro requirement. Some countries require hydros every TWO years. So don't give us the bullsh*t that the DOT is some overprotective agency compared to the rest of the world. The FACTS are not there for such a statement.
You are a danger to other divers!!!!
You seriously need to look at overseas hydro requirement. Some countries require hydros every TWO years. So don't give us the bullsh*t that the DOT is some overprotective agency compared to the rest of the world. The FACTS are not there for such a statement.
You are a danger to other divers!!!!
Leadking
Contributor
Quote from KSW "I can guess that there is no answer other than the US is more cautious than overseas"
I have spent YEARS trying to debunk myths and rumors. I have always gone to cylinder engineers, the DOT, and other reputable sources and can give the source on any posts regarding cylinder safety. If I didn't know the facts, I went to someone who did. Do what you want, but I will continually challenge those who do not pass on truthful reliable knowledge
KSW read this about lp vs. hp cylinders
From my post of FEB 14, 2007
U.S.tensile strength (105,000-125,000 psi for 3AA cylinders) is not the same as European tensile strength (135,000-155,000 psi as required by EN 1964 part 1 and ISO 9809 part 1) and I have test data that shows Faber cylinders delivered to us show a tensile strength of 115,000-123,000 psi for their 3AA cylinders (as required by DOT)
As an example, all of the E cylinders, Exempt or soon to be SP, Special Permit cylinders are made from a harder steel and cannot exceed 159,000 psi yield which exceeds 3AA tensile yield by as much as 50%. As you can see the E/SP cylinders being produced more closely follow the European metallurgy which allows for higher pressures.
view all the posts at
http://www.scubaboard.com/showthread...hlight=tensile
Last edited:
Similar threads
