What do you use for your general algorithm for capital improvements
that save money (such as solar energy & buying your own tanks)?
- solar
- wood-fired heating
- owning your own propane tanks
etc.

For example, in another thread, I found out the propane company
changed their prices such that the break-even point between buying
my own propane tank versus renting it changed.

For example, for a 500 gallon tank, they charge $95/year and for
a 1,000 gallon tank, they charge $120/year.

If both tanks cost $1,000 to own (there really is no maintenance to
speak of for these things), then the break-even point is 10-1/2 years
for the small tank, and 8-1/3 years for the bigger tank.

My general algorithm is roughly that anything around 5 years is a
no brainer, and anything under about 10 years is a worthwhile deal
(since I plan in dying in this house).

But, anything that has a payback of 15 to 20 years may not be a
good deal, since I'm not gonna live much longer than that.

What's your payback algorithm for capital improvements such as
solar energy (which costs about $50K but which starts saving money
on day one, especially at high-tier rates of 50 cents per kWh).

Is it 5 years? 10? 20?

Alex Gunderson wrote:

....snip...


What's your payback algorithm for capital improvements such as
solar energy (which costs about $50K but which starts saving money
on day one, especially at high-tier rates of 50 cents per kWh).

Is it 5 years? 10? 20?

An algorithm isn't a number, it's a step by step procedure.

On Fri, 27 Sep 2013 18:38:29 +0000, DerbyDad03 wrote:

An algorithm isn't a number, it's a step by step procedure.

OK. That's what I wanted, even if *mine* boils down to a break-even
point.

But what's important isn't *my* algorithm, but yours.

Alex Gunderson wrote:
On Fri, 27 Sep 2013 18:38:29 +0000, DerbyDad03 wrote:

An algorithm isn't a number, it's a step by step procedure.

OK. That's what I wanted, even if *mine* boils down to a break-even
point.

But what's important isn't *my* algorithm, but yours.

You are not making any sense.

You specifically asked...

What's your payback algorithm for capital improvements...is it 5 years? 10?
20?

What are you really looking for? A number, like you asked for, or the
specific steps that one would go through to find a break even point for a
capital improvement, i.e. an algorithm?

On 9/27/2013 11:23 AM, Alex Gunderson wrote:
What do you use for your general algorithm for capital improvements
that save money (such as solar energy & buying your own tanks)?
- solar
- wood-fired heating
- owning your own propane tanks
etc.

For example, in another thread, I found out the propane company
changed their prices such that the break-even point between buying
my own propane tank versus renting it changed.

For example, for a 500 gallon tank, they charge $95/year and for
a 1,000 gallon tank, they charge $120/year.

If both tanks cost $1,000 to own (there really is no maintenance to
speak of for these things), then the break-even point is 10-1/2 years
for the small tank, and 8-1/3 years for the bigger tank.

My general algorithm is roughly that anything around 5 years is a
no brainer, and anything under about 10 years is a worthwhile deal
(since I plan in dying in this house).

But, anything that has a payback of 15 to 20 years may not be a
good deal, since I'm not gonna live much longer than that.

What's your payback algorithm for capital improvements such as
solar energy (which costs about $50K but which starts saving money
on day one, especially at high-tier rates of 50 cents per kWh).

Is it 5 years? 10? 20?


there are intangibles as well as a $ cost. for instance, one might want
to go solar 'for the good of the planet', and what is that cost or
savings to that person comes into play. there's also other inducements:
not having to pay for a resource, or rebates, for example, that might
expire.

it might also be what the opportunity loss of investments costs you. an
example, a few years ago, i put in a solar array. payback time was 4.5
years, which gave me almost a 20% roi. no brainer, as a safe investment
was earning far less.

On Friday, September 27, 2013 3:42:20 PM UTC-4, chaniarts wrote:
On 9/27/2013 11:23 AM, Alex Gunderson wrote:

What do you use for your general algorithm for capital improvements

that save money (such as solar energy & buying your own tanks)?

- solar

- wood-fired heating

- owning your own propane tanks

etc.



For example, in another thread, I found out the propane company

changed their prices such that the break-even point between buying

my own propane tank versus renting it changed.



For example, for a 500 gallon tank, they charge $95/year and for

a 1,000 gallon tank, they charge $120/year.



If both tanks cost $1,000 to own (there really is no maintenance to

speak of for these things), then the break-even point is 10-1/2 years

for the small tank, and 8-1/3 years for the bigger tank.



My general algorithm is roughly that anything around 5 years is a

no brainer, and anything under about 10 years is a worthwhile deal

(since I plan in dying in this house).



But, anything that has a payback of 15 to 20 years may not be a

good deal, since I'm not gonna live much longer than that.



What's your payback algorithm for capital improvements such as

solar energy (which costs about $50K but which starts saving money

on day one, especially at high-tier rates of 50 cents per kWh).



Is it 5 years? 10? 20?





there are intangibles as well as a $ cost. for instance, one might want

to go solar 'for the good of the planet', and what is that cost or

savings to that person comes into play. there's also other inducements:

not having to pay for a resource, or rebates, for example, that might

expire.



it might also be what the opportunity loss of investments costs you. an

example, a few years ago, i put in a solar array. payback time was 4.5

years, which gave me almost a 20% roi. no brainer, as a safe investment

was earning far less.

Excellent point. The Return On Investment is 1 divided by the years it takes to pay back the original investment. If you have enough available to pay cash, you'd consider in investing in anything paying more than what you could get by investing the money, which is around 1% these days. If you're paying off a big credit card debt at 18%, you'd be better off paying off the credit card unless your investment pays back a lot more. And if you have to borrow to make the improvement, you'd deduct the annual interest costs of the loan from the return to compute your payback.

I work in financial analysis at a hospital and our management likes capital investments to pay back in two years, i.e., a 50% ROI. Not always possible, but that's sort of the benchmark. Of course, they have dozens of requests each week and have to decide which they can afford.

On Fri, 27 Sep 2013 12:59:56 -0700, Pavel314 wrote:

I work in financial analysis at a hospital and our management likes
capital investments to pay back in two years, i.e., a 50% ROI. Not always
possible, but that's sort of the benchmark.

THIS is the kind of real-world example that I was looking for!

I'm surprised the payback is so short though.

I would have considered 5 years as a no brainer.

In your case above, 5 years would be too long and you're rent instead.

On Fri, 27 Sep 2013 15:48:46 -0400, wrote:



Generally speaking things like renovations beyond cleaning and
painting seldom make economic sense. You do it for you.


Yep. Some things might be exceptions. Insulation and the like.
I replaced all my old windows with thermopanes. Pretty sure the ROI
was good, because I got it done cheap and it made a big difference in
heating/cooling costs. Not to mention maintenance costs.
But I mainly did it for me. Didn't have to paint the old ones, and
the new ones look much better to me and my wife.

On Fri, 27 Sep 2013 18:23:53 +0000 (UTC), Alex Gunderson
wrote:

What do you use for your general algorithm for capital improvements
that save money (such as solar energy & buying your own tanks)?
- solar

Forget it.

- wood-fired heating

Forget it, unless you want the ambiance or backup heat. ...or need a
constant source of painful exercise, I suppose.

- owning your own propane tanks

If the "present value" of the "rent" exceeds the rent over your
desired payback time, buy. If not, rent. You decide what interest
rate and payback time is of interest to you.

http://www.investopedia.com/calculator/pvcal.aspx
Enter your interest rate, the number of periods (months or years), and
the total paid over that time (payment times periods) and the result
is the current value of that money. For example, if you paid $200 per
year for five years ($1000 total) at 6% interest, it would be the same
as paying $747.26 today.

If you want to go the other way:
http://www.investopedia.com/calculator/fvcal.aspx
Enter the current price of the gas tank, interest rate, and number of
months, and this will tell you the payments over that time. If the
payments are less than this, don't buy.


etc.

For example, in another thread, I found out the propane company
changed their prices such that the break-even point between buying
my own propane tank versus renting it changed.


For example, for a 500 gallon tank, they charge $95/year and for
a 1,000 gallon tank, they charge $120/year.

If both tanks cost $1,000 to own (there really is no maintenance to
speak of for these things), then the break-even point is 10-1/2 years
for the small tank, and 8-1/3 years for the bigger tank.

My general algorithm is roughly that anything around 5 years is a
no brainer, and anything under about 10 years is a worthwhile deal
(since I plan in dying in this house).

But, anything that has a payback of 15 to 20 years may not be a
good deal, since I'm not gonna live much longer than that.

What's your payback algorithm for capital improvements such as
solar energy (which costs about $50K but which starts saving money
on day one, especially at high-tier rates of 50 cents per kWh).

Is it 5 years? 10? 20?

That's entirely your decision. Obviously, this can't be longer than
you're likely to own the widget unless there will be a residual value
that someone else will pay you for.

On 9/27/2013 11:23 AM, Alex Gunderson wrote:
What do you use for your general algorithm for capital improvements
that save money (such as solar energy & buying your own tanks)?
- solar
- wood-fired heating
- owning your own propane tanks
etc.

For example, in another thread, I found out the propane company
changed their prices such that the break-even point between buying
my own propane tank versus renting it changed.

For example, for a 500 gallon tank, they charge $95/year and for
a 1,000 gallon tank, they charge $120/year.

If both tanks cost $1,000 to own (there really is no maintenance to
speak of for these things), then the break-even point is 10-1/2 years
for the small tank, and 8-1/3 years for the bigger tank.

My general algorithm is roughly that anything around 5 years is a
no brainer, and anything under about 10 years is a worthwhile deal
(since I plan in dying in this house).

But, anything that has a payback of 15 to 20 years may not be a
good deal, since I'm not gonna live much longer than that.

What's your payback algorithm for capital improvements such as
solar energy (which costs about $50K but which starts saving money
on day one, especially at high-tier rates of 50 cents per kWh).

Is it 5 years? 10? 20?

There ain't one. You do the math based on ALL the factors for each
situation.

The wild card in everything is your ability to predict the future.
In 1998, would you have predicted the current economic climate?
If you have extra cash lying around, that may affect your decision.

People often fail to consider all the factors.
If the company owns the tank, who pays for the required inspections?
Does that limit your choice of vendors?
Who is liable if it explodes?

Even if it looks favorable, there may be other better alternative uses for
your cash than to invest in a tank.

If you can't decide, it probably doesn't need fixing.

Some decisions are trivial.
If you have access to the "grid", there's only one way to make solar
electricity pencil out. Get someone else to pay for it.

Diminishing returns on weatherization comes early.
If you've got no insulation, you should get some.
Otherwise, do the math carefully.

I know a guy who fell into the sweet spot of stimulus money.
They paid $14K to weatherize his house. Saves him money, but
less than the interest on $14K he would have borrowed to install it
himself...assuming anybody would have loaned him $14K...

On Fri, 27 Sep 2013 20:05:02 -0400, krw wrote:

If the "present value" of the "rent" exceeds the rent over your desired
payback time, buy. If not, rent. You decide what interest rate and
payback time is of interest to you.

This is pretty much what I use.

I'm guessing anything within the life of the thing or the life of how
long you'll actually be living in that house is fair game.

For example, if you only plan on living at that house for, oh, say,
5 years, then it would seem to me that the payback has to be
shorter (say, a year or two) for you to go for it.

Likewise, if you're planning on living there for 20 years, then
you might go with a 10 year payback period for some things.

On Fri, 27 Sep 2013 17:23:31 -0700, mike wrote:

The wild card in everything is your ability to predict the future.

True. But some things are very predictable.

For example, how much will solar panels cost to put in is
pretty predictable.

And, how much energy will they generate is also very predictable
(since you're not the first person to do it, they have the tables).

The maintenance, I agree, might not be predictable, but, if everyone
really made decisions that way, we'd all leave California the
day before an earthquake, and then come back the next day.

On Sat, 28 Sep 2013 02:33:42 +0000 (UTC), Alex Gunderson
wrote:

On Fri, 27 Sep 2013 20:05:02 -0400, krw wrote:

If the "present value" of the "rent" exceeds the rent over your desired
payback time, buy. If not, rent. You decide what interest rate and
payback time is of interest to you.

This is pretty much what I use.

I'm guessing anything within the life of the thing or the life of how
long you'll actually be living in that house is fair game.

For example, if you only plan on living at that house for, oh, say,
5 years, then it would seem to me that the payback has to be
shorter (say, a year or two) for you to go for it.

Remember maintenance and insurance costs, too. Some things like solar
panels may or may not be covered under a normal homeowners policy (or
may require additional coverage or a rider). One hail storm can ruin
your whole day.

Likewise, if you're planning on living there for 20 years, then
you might go with a 10 year payback period for some things.

That's the real decision, once you get past "I wanna have it". ;-)

On Fri, 27 Sep 2013 17:23:31 -0700, mike wrote:

Even if it looks favorable, there may be other better alternative uses
for your cash than to invest in a tank.

That's true.

For example, I just found out the "real" price for a 1000-gallon tank
given that I'm in this propane-buyer's cooperative is listed he
http://www.southskyline.org/skyprop.html

A 1,000-gallon tank would cost $1,600 to have delivered to my doorstep.
Figure the concrete pad, trenching, conduit, risers, regulator & pigtail
add another what? I don't know, maybe $400 at DIY prices? That's $2000.

So, my costs are $2000 and the setup is inspected & good to go.

Currently my coop has a contract for wholesale + 56 cents:
http://www.southskyline.org/spug.html

If I saved, say, 20 cents per gallon by being able to switch suppliers,
it would take me 10,000 gallons to break even.

At 2,000 gallons of propane a year, that would be in about 5 years.
Five years to break even seems like a decent deal, to me.

On 9/27/2013 8:34 PM, Alex Gunderson wrote:
On Fri, 27 Sep 2013 17:23:31 -0700, mike wrote:

Even if it looks favorable, there may be other better alternative uses
for your cash than to invest in a tank.

That's true.

For example, I just found out the "real" price for a 1000-gallon tank
given that I'm in this propane-buyer's cooperative is listed he
http://www.southskyline.org/skyprop.html

A 1,000-gallon tank would cost $1,600 to have delivered to my doorstep.
Figure the concrete pad, trenching, conduit, risers, regulator & pigtail
add another what? I don't know, maybe $400 at DIY prices? That's $2000.

So, my costs are $2000 and the setup is inspected & good to go.

Currently my coop has a contract for wholesale + 56 cents:
http://www.southskyline.org/spug.html

If I saved, say, 20 cents per gallon by being able to switch suppliers,
it would take me 10,000 gallons to break even.

At 2,000 gallons of propane a year, that would be in about 5 years.
Five years to break even seems like a decent deal, to me.

I missed the part where you took the cost of money into account.
You can borrow the $2000 and pay interest.
You can take it out of savings and lose interest.
Or you can take it out of savings and use it to pay off higher interest
loans instead of buying a tank.
The cost of money is the lowest interest rate to borrow it
or the highest rate you're paying on current loans minus what it's
earning now...whichever is greater. That can really skew your analysis.

And if you already have a tank, you can just buy it from the current
owner...or pay to have it decommissioned and hauled away so you can
replace the current system.

On Sat, 28 Sep 2013 03:42:45 -0700, mike wrote:

On 9/27/2013 8:34 PM, Alex Gunderson wrote:
On Fri, 27 Sep 2013 17:23:31 -0700, mike wrote:

Even if it looks favorable, there may be other better alternative uses
for your cash than to invest in a tank.

That's true.

For example, I just found out the "real" price for a 1000-gallon tank
given that I'm in this propane-buyer's cooperative is listed he
http://www.southskyline.org/skyprop.html

A 1,000-gallon tank would cost $1,600 to have delivered to my doorstep.
Figure the concrete pad, trenching, conduit, risers, regulator & pigtail
add another what? I don't know, maybe $400 at DIY prices? That's $2000.

So, my costs are $2000 and the setup is inspected & good to go.

Currently my coop has a contract for wholesale + 56 cents:
http://www.southskyline.org/spug.html

If I saved, say, 20 cents per gallon by being able to switch suppliers,
it would take me 10,000 gallons to break even.

At 2,000 gallons of propane a year, that would be in about 5 years.
Five years to break even seems like a decent deal, to me.

I missed the part where you took the cost of money into account.
You can borrow the $2000 and pay interest.
You can take it out of savings and lose interest.

My mother had this discussion with her bridge group (3 other women)
about 45 years ago, about comparing the cost of renting versus buying.
She told me they just couldn't understand where the cost of money came
into the picture. My mother did.

Or you can take it out of savings and use it to pay off higher interest
loans instead of buying a tank.
The cost of money is the lowest interest rate to borrow it
or the highest rate you're paying on current loans minus what it's
earning now...whichever is greater. That can really skew your analysis.




And if you already have a tank, you can just buy it from the current
owner...or pay to have it decommissioned and hauled away so you can
replace the current system.

On Mon, 30 Sep 2013 23:12:32 -0400, bubba wrote:

My mother had this discussion with her bridge group (3 other women)
about 45 years ago, about comparing the cost of renting versus buying.
She told me they just couldn't understand where the cost of money came
into the picture.

Heh heh. I think actually these kinds of basic misconceptions
are why we're not able to instantly come to a concerted agreement
on the legal status of propane tanks sold with the house.

For example, I just found out why the bulk of the confusion is in
the definition of REAL property versus PERSONAL property.

In California, it's pretty clear propane tanks are taxed as
REAL PROPERTY, e.g., http://www.calproptax.com/1proprty.html

In other states, propane tanks are considered PERSONAL PROPERTY.
For example, in NJ:
http://www.lawrenceyerkes.com/html/r...l-property.htm

We find that the propane industry argues vehemently that they feel
propane tanks, in California, should NOT be classified as REAL PROPERTY:
http://www.boe.ca.gov/proptaxes/pdf/ip99052.pdf
"Industry, the Western Propane Gas Association, disagrees with staff's
recommendation. Industry believes butane and propane tanks should be
classified as personal property."
[versus historically being classified as "improvements" by the state]

Yet, clearly, California classifies (and taxes) above-ground propane
tanks as REAL PROPERTY (same paper as above).

Also, we find a huge amount of the confusion on the status of propane
tanks is directly related to the fact that they are UNIQUE.

Even the industry argues they are unique - and that they should be
treated as an entity upon themselves, for a variety of reasons,
as explained he
http://www.boe.ca.gov/proptaxes/pdf/ip99051.pdf

So, in summary, a HUGE amount of the confusion here is that California
treats above-ground propane tanks as REAL PROPERTY and that all examples
that are *not* about propane tanks fail to adequately explain the
unique treatment of propane tanks in California.

Alex:

I don't know about the USA, but here in Canada, all cylinders designed to store gas under pressure have to be pressure certified every 5 years.

This is the primary reason that most companies that use compressed gasses in their business prefer to buy the gas but simply pay a damage deposit on the cylinder so that ownership of the cylinder stays with the company supplying the compressed gas. That's cuz whomever owns the cylinder is responsible for paying to have it pressure certified periodically.

I make my own beer, and I use beer gas in a cast steel cylinder to drive it out of a spigot on my beer fridge. That's how I know about the pressure certification requirement.

So, as regards the cylinder itself, be sure you have all the numbers before you start doing the math. Maybe contact your propane utility and find out if there are any costs associated with ownership of the equipment you rent.


Diy'ers don't really figure out the pay out time on a project. Your example where you figure that if you're only going to live in a house for 10 years, you want the projects you do to pay out in less time than that really doesn't work in real life. For example, suppose you needed to put new shingles on your roof. The labor involved in installing more expensive 30 year shingles is no different than the labor involved in installing much less expensive 15 year shingles. So, who would say I'm going to work my butt off installing these cheap shingles and then have to do it all again in 15 years, whereas if I paid 50 percent more for the shingles, I won't have to do it again for 30 years? It just makes economic horse sense to pay more for the materials if the labor costs are the same regardless of what kind of quality you install.

Similarily, when it comes to installing carpet, who's going to install the cheapest rubber backed carpet they can find because they don't plan to live in the house for more than another 5 years? That would be a BAD economic decision because any prospective purchaser of the house would lower their offer by the cost to replace the carpet. Installing a good quality carpet up front costs more, but it also doesn't diminish the value of the house when it comes time to sell.

So, this DIY business doesn't lend itself well to the mathematics you're wanting to use.

On Tue, 1 Oct 2013 06:15:26 +0200, nestork
wrote:


Alex:

I don't know about the USA, but here in Canada, all cylinders designed
to store gas under pressure have to be pressure certified every 5
years.

This is the primary reason that most companies that use compressed
gasses in their business prefer to buy the gas but simply pay a damage
deposit on the cylinder so that ownership of the cylinder stays with the
company supplying the compressed gas. That's cuz whomever owns the
cylinder is responsible for paying to have it pressure certified
periodically.

Propane is a little different than compressed gas. LP (the 'L' stands
for LIQUID) is only under 200PSI, not the 3,000+ PSI used for gasses.
It makes a huge difference. That's the reason LP is preferred over
CNG.

I make my own beer, and I use beer gas in a cast steel cylinder to drive
it out of a spigot on my beer fridge. That's how I know about the
pressure certification requirement.

At probably 3000PSI.

...

On Tue, 01 Oct 2013 06:15:26 +0200, nestork wrote:

I don't know about the USA, but here in Canada, all cylinders designed to
store gas under pressure have to be pressure certified every 5 years.

Down here, these huge tanks (they're fifteen feet long) are certified
at the factory, AFAIK, and that's the end of it.

Every dozen (or so) years they replace the regulators.

And, every new delivery company runs a complete hour-long inspection
of the tank, fittings, and premises (inside & outside the house).

I doubt these things are exploding left and right, so, for safety,
that's apparently just fine.

I'll tell you the least of my worries is the tank causing a hazard.

I'd worry more about a thousand other items in the house, not the
least of which are my kid's friends.

On Tue, 01 Oct 2013 06:15:26 +0200, nestork wrote:

I make my own beer, and I use beer gas in a cast steel cylinder to drive
it out of a spigot on my beer fridge. That's how I know about the
pressure certification requirement.

I have a whole bunch of tanks, carbon dioxide, acetylene, oxygen,
scuba, etc., and I know all about the certification for those.

It's no big deal.

The only ones afraid of it are the ones who never had it done
(and those people are afraid of everything anyway).

On Tue, 01 Oct 2013 06:15:26 +0200, nestork wrote:

It just makes
economic horse sense to pay more for the materials if the labor costs are
the same regardless of what kind of quality you install.

In general, and this is a long shot because it's a general equation,
the crap that the construction guys puts in saves THEM a dollar a
job, but only saves you a total of 1 dollar, which you don't even
get to save because they typically charge you something like double
what it would cost you for the same materials.

So, as an algorithm, I do it myself, and I buy the best material.
If I pay someone to do it, they often buy the cheapest material,
or, charge me double than it would cost me for better material.

In the end, the DIY wins because they LEARN (if that's your shtick).
And, the DIY gets the absolute best materials.
At the lowest total costs.

The tradeoff is time. Lots of time in most cases.

On Tue, 01 Oct 2013 15:48:59 -0400, wrote:

On Tue, 1 Oct 2013 06:15:26 +0200, nestork
wrote:


Alex:

I don't know about the USA, but here in Canada, all cylinders designed
to store gas under pressure have to be pressure certified every 5
years.

This is the primary reason that most companies that use compressed
gasses in their business prefer to buy the gas but simply pay a damage
deposit on the cylinder so that ownership of the cylinder stays with the
company supplying the compressed gas. That's cuz whomever owns the
cylinder is responsible for paying to have it pressure certified
periodically.

Propane is a little different than compressed gas. LP (the 'L' stands
for LIQUID)

But what does the 'G' stand for in LPG?

Propane at room temperature and pressure is a gas. It changes to a
liquid when it's under pressure.

The rest of what you say may well be true.

is only under 200PSI, not the 3,000+ PSI used for gasses.
It makes a huge difference. That's the reason LP is preferred over
CNG.

I make my own beer, and I use beer gas in a cast steel cylinder to drive
it out of a spigot on my beer fridge. That's how I know about the
pressure certification requirement.

At probably 3000PSI.

When my friend was sick, they hired an LPN, a liquid petroleum nurse.
She would run all over the place.

On 10/2/2013 11:47 AM, micky wrote:
On Tue, 01 Oct 2013 15:48:59 -0400, wrote:

On Tue, 1 Oct 2013 06:15:26 +0200, nestork
wrote:


Alex:

I don't know about the USA, but here in Canada, all cylinders designed
to store gas under pressure have to be pressure certified every 5
years.

This is the primary reason that most companies that use compressed
gasses in their business prefer to buy the gas but simply pay a damage
deposit on the cylinder so that ownership of the cylinder stays with the
company supplying the compressed gas. That's cuz whomever owns the
cylinder is responsible for paying to have it pressure certified
periodically.

Propane is a little different than compressed gas. LP (the 'L' stands
for LIQUID)

But what does the 'G' stand for in LPG?

Propane at room temperature and pressure is a gas. It changes to a
liquid when it's under pressure.

The rest of what you say may well be true.

it's also called Liquified Petroleum Gas, which by definition is
petroleum gas stored as a liquid, and by definition, is not a gas.

propane in a tank is liquid, and thus there is very little 'gas' in the
tank, so the pressure is far less than a tank of only gas that is not
actually stored in a liquid state.

think of a dewar flask of liquid nitrogen. it's not pressurized at all,
and the nitrogen is changing from liquid to gas all the time if the
flask is opened, due to rising temp.

is only under 200PSI, not the 3,000+ PSI used for gasses.
It makes a huge difference. That's the reason LP is preferred over
CNG.

I make my own beer, and I use beer gas in a cast steel cylinder to drive
it out of a spigot on my beer fridge. That's how I know about the
pressure certification requirement.

At probably 3000PSI.

When my friend was sick, they hired an LPN, a liquid petroleum nurse.
She would run all over the place.

I make my own beer, and I use beer gas in a cast steel cylinder to drive
it out of a spigot on my beer fridge. That's how I know about the
pressure certification requirement.

What is "beer gas"? I know the results of drinking too much beer, but it doesn't come in any cast steeel cylindersg!!

On Wed, 02 Oct 2013 12:10:54 -0700, wrote:

I make my own beer
That's how I know about the pressure certification requirement.

Does anyone know how often a 1,000 gallon propane tank is pressure certified?

How long do these huge propane tanks "typically" last anyway?

And how often, after their made, are they tested for pressure?

Zero? Once every 20 years?

Any idea? Any experience?

On Wed, 02 Oct 2013 12:00:07 -0700, chaniarts wrote:

propane in a tank is liquid, and thus there is very little 'gas' in the
tank, so the pressure is far less than a tank of only gas that is not
actually stored in a liquid state.

Googling for how much pressure is in a propane tank, I find this blurb:

"The pressure in a propane tank varies with the temperature of the
liquid in it. Volume is not a factor. At -44°F the pressure is 0 psi.
As the temperature increases from there, so does the pressure. At 0°F
you have about 28 psi, at 32°F about 60 psi.
At 72°F about 130 psi and at 100°F close to 200 psi."

So, these huge steel things are only holding a couple hundred PSI.

How often are they 'pressure certified' anyway?

When do you normally 'expire' a propane tank anyway?

20 years? 40 years? 100 years?

On Wed, 02 Oct 2013 14:47:15 -0400, micky
wrote:

On Tue, 01 Oct 2013 15:48:59 -0400, wrote:

On Tue, 1 Oct 2013 06:15:26 +0200, nestork
wrote:


Alex:

I don't know about the USA, but here in Canada, all cylinders designed
to store gas under pressure have to be pressure certified every 5
years.

This is the primary reason that most companies that use compressed
gasses in their business prefer to buy the gas but simply pay a damage
deposit on the cylinder so that ownership of the cylinder stays with the
company supplying the compressed gas. That's cuz whomever owns the
cylinder is responsible for paying to have it pressure certified
periodically.

Propane is a little different than compressed gas. LP (the 'L' stands
for LIQUID)

But what does the 'G' stand for in LPG?

Government?

Propane at room temperature and pressure is a gas. It changes to a
liquid when it's under pressure.

Or cold enough.

The rest of what you say may well be true.

It is.

is only under 200PSI, not the 3,000+ PSI used for gasses.
It makes a huge difference. That's the reason LP is preferred over
CNG.

I make my own beer, and I use beer gas in a cast steel cylinder to drive
it out of a spigot on my beer fridge. That's how I know about the
pressure certification requirement.

At probably 3000PSI.

When my friend was sick, they hired an LPN, a liquid petroleum nurse.
She would run all over the place.

Probably stunk like rotten eggs, too.

On Wed, 02 Oct 2013 12:00:07 -0700, chaniarts
wrote:

On 10/2/2013 11:47 AM, micky wrote:
On Tue, 01 Oct 2013 15:48:59 -0400, wrote:

On Tue, 1 Oct 2013 06:15:26 +0200, nestork
wrote:


Alex:

I don't know about the USA, but here in Canada, all cylinders designed
to store gas under pressure have to be pressure certified every 5
years.

This is the primary reason that most companies that use compressed
gasses in their business prefer to buy the gas but simply pay a damage
deposit on the cylinder so that ownership of the cylinder stays with the
company supplying the compressed gas. That's cuz whomever owns the
cylinder is responsible for paying to have it pressure certified
periodically.

Propane is a little different than compressed gas. LP (the 'L' stands
for LIQUID)

But what does the 'G' stand for in LPG?

Propane at room temperature and pressure is a gas. It changes to a
liquid when it's under pressure.

The rest of what you say may well be true.

it's also called Liquified Petroleum Gas, which by definition is
petroleum gas stored as a liquid, and by definition, is not a gas.

propane in a tank is liquid, and thus there is very little 'gas' in the
tank, so the pressure is far less than a tank of only gas that is not
actually stored in a liquid state.

think of a dewar flask of liquid nitrogen. it's not pressurized at all,
and the nitrogen is changing from liquid to gas all the time if the
flask is opened, due to rising temp.

Right but if that Dewar is sealed, the pressure will increase
dramatically. LP has a fairly high boiling point and can exist as a
liquid at room temperature at a fairly low pressure. If you're really
interested in this stuff you can look up the "phase diagrams" of
various chemicals. I'd look up Nitrogen now but I'm waiting to board
a flight and disconnected.

On 10/2/2013 4:48 PM, Alex Gunderson wrote:


So, these huge steel things are only holding a couple hundred PSI.

How often are they 'pressure certified' anyway?

When do you normally 'expire' a propane tank anyway?

20 years? 40 years? 100 years?


The 20# tanks for a grill are dated and expire or have to be tested
after 12 years.

Large tanks must conform to certain specifications of ASME
(Amer.Soc.Mech.Eng) but I don't know about testing. Most pressure
vessels are checked for corrosion using ultrasonic instruments.

On 10/2/2013 6:41 PM, wrote:

Propane is a little different than compressed gas. LP (the 'L' stands
for LIQUID)

But what does the 'G' stand for in LPG?

Government?
CY: yeah, but it's compressed government.


Propane at room temperature and pressure is a gas. It changes to a
liquid when it's under pressure.

Or cold enough.
CY: Ha, you're going to educate usenet readers?


The rest of what you say may well be true.

It is.
CY: We knew that.


is only under 200PSI, not the 3,000+ PSI used for gasses.
It makes a huge difference. That's the reason LP is preferred over
CNG.

CY: Lot of tanks that CNG gets....


When my friend was sick, they hired an LPN, a liquid petroleum nurse.
She would run all over the place.

Probably stunk like rotten eggs, too.

CY: Only if she was properly odorized.




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