Is a used propane tank really cheaper?

stand up or sit down...to sink or not to sink...want or got gas...post your Q&A here..........

Postby Larry C » Tue Jun 14, 2011 5:03 pm

dh wrote:I've read about this while researching the recertification process. As steel prices went up, tank wall thickness went down, as did the pressure rating.


Larry, when you hydro test a hose, how much pressure do you put on it?


dh,
The hoses I work with are High Pressure which have a MWP (max working press) of 350 PSI for LPG (1 PSI for nat gas). The layline on the hose will show the MWP.

Some guidelines recommend a new hose assy. be tested at 2 times the WP (working pressure). In this case, 350PSI WP= 700PSI test pressure (proof pressure). Used hose at 1.5 times WP. For safety I do all testing in a 1/4" welded steel containment box!!

Hydrostatic testing should only be preformed by trained personnel. Also hydro testing is just a spot check to confirm the assembly meets specifications at the time of the test. However, many conditions affect the performance of a hose when it's put into service. Age, operating environment, etc. all affect the longevity of any hose. Periodic re-testing or replacement is strongly recommended.

BTW/ I wouldn't recommend using high pressure air to test your "old" bottle.

L
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Postby dh » Tue Jun 14, 2011 9:17 pm

Larry C wrote:
dh wrote:I've read about this while researching the recertification process. As steel prices went up, tank wall thickness went down, as did the pressure rating.


Larry, when you hydro test a hose, how much pressure do you put on it?


dh,
The hoses I work with are High Pressure which have a MWP (max working press) of 350 PSI for LPG (1 PSI for nat gas). The layline on the hose will show the MWP.

Some guidelines recommend a new hose assy. be tested at 2 times the WP (working pressure). In this case, 350PSI WP= 700PSI test pressure (proof pressure). Used hose at 1.5 times WP. For safety I do all testing in a 1/4" welded steel containment box!!

Hydrostatic testing should only be preformed by trained personnel. Also hydro testing is just a spot check to confirm the assembly meets specifications at the time of the test. However, many conditions affect the performance of a hose when it's put into service. Age, operating environment, etc. all affect the longevity of any hose. Periodic re-testing or replacement is strongly recommended.

BTW/ I wouldn't recommend using high pressure air to test your "old" bottle.

L


Do you consider 150 PSI high pressure?

I was asking more for my own curiosity than anything else. I knew it had to be HIGH to get water spraying out of the hose jacket. I've experiance hydraulic hose failures first hand in both ag and industrial settings. The latter on a gas oven door. The hydraulic fluid caught on fire as it was spraying everywhere, almost burnt the entire factory down.
Ignorant doesn't know any better, Stupid knows better but does it anyway.

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Postby Larry C » Thu Jun 16, 2011 5:31 pm

dh wrote:
Larry C wrote:
dh wrote:I've read about this while researching the recertification process. As steel prices went up, tank wall thickness went down, as did the pressure rating.


Larry, when you hydro test a hose, how much pressure do you put on it?


dh,
The hoses I work with are High Pressure which have a MWP (max working press) of 350 PSI for LPG (1 PSI for nat gas). The layline on the hose will show the MWP.

Some guidelines recommend a new hose assy. be tested at 2 times the WP (working pressure). In this case, 350PSI WP= 700PSI test pressure (proof pressure). Used hose at 1.5 times WP. For safety I do all testing in a 1/4" welded steel containment box!!

Hydrostatic testing should only be preformed by trained personnel. Also hydro testing is just a spot check to confirm the assembly meets specifications at the time of the test. However, many conditions affect the performance of a hose when it's put into service. Age, operating environment, etc. all affect the longevity of any hose. Periodic re-testing or replacement is strongly recommended.

BTW/ I wouldn't recommend using high pressure air to test your "old" bottle.

L


Do you consider 150 PSI high pressure?

I was asking more for my own curiosity than anything else. I knew it had to be HIGH to get water spraying out of the hose jacket. I've experiance hydraulic hose failures first hand in both ag and industrial settings. The latter on a gas oven door. The hydraulic fluid caught on fire as it was spraying everywhere, almost burnt the entire factory down.


Yes........... Inducing compressed air into a vessel that was not intended for compressed air can be catastrophic. 150 psi is substantial if it lets loose!!

A friend of mine had a small 10x15 shop he used for servicing high end bicycles. The shop was loaded with expensive tools for working on bikes, and frames, etc. He had a small tank mounted 1/2 HP air compressor he had used for years.

He was in his shop and his dog decided a walk was needed. When he returned 15 minutes later, his entire shop was destroyed!!
The SMALL air compressor's limit switch failed, and there was no safety pop off. The result was like a bomb had gone off.

He told me the largest piece he found was about 1.5" Almost every square inch of the inside of the shop had shrapnel marks on it, the walls, tools, cabinets, bicycles, etc. All windows were blown out. There were pieces of steel embedded in the walls. Thousands in damage. All from a small air compressor tank letting loose. I doubt the compressor could achieve much over 175 PSI without the belt slipping.

Again...... I advise against using compressed air to test your bottle.
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Postby dh » Thu Jun 16, 2011 8:56 pm

So, your saying I shouldn't test the valve, that I'm gonna take out and replace, for leaks till I get it filled with propane?
Ignorant doesn't know any better, Stupid knows better but does it anyway.

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