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jon_banquer[_2_] jon_banquer[_2_] is offline
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Default Nat gas pressure drop vs. pipe length

On Jan 8, 8:38*pm, "Existential Angst" wrote:
"jon_banquer" wrote in message

...
On Jan 8, 7:02 pm, "Existential Angst" wrote:









"jon_banquer" wrote in message


....
On Jan 8, 6:13 pm, "Existential Angst" wrote:


"jon_banquer" wrote in message


....
On Jan 8, 5:43 pm, "Existential Angst" wrote:


OK, took delivery of a 15,000 W tri-fuel generator, with a Honda GX690
motor, 690 cc, about 22 hp.
Couldn't get it to run off propane, cuz their regulator (that attaches
to
the tank itself) seems to be faulty. Haven't tried gasoline yet.


So I was able to kluge together a nat gas connection, some distance
away,
via a 50 ft coil of 3/8 id air hose.... yeah, I know, I know, chill,
it
was
just a test.....


Generator ran fine, and I was a little surprised, given the narrow id
and
rel. long hose length. Under no-load conditions.


So here's the Q:
With typical natural gas pressure (I'm sposing 5-7" water), how much
actual load (hp) can be powered with 1/2" black pipe, of negligible
length?
Or, per actual sq in of pipe cross section. And then, how would that
power
capacity drop off with pipe length?


This will affect the size of the piping, and poss. the location of the
unit.
Tomorrow, I will wire up some temp. elec connections, and load as many
heaters etc as I can, to see if I can detect some fuel-bottleneck
under
heavy load, thru 50 ft of 3/8" hose. If there is no perceptible
bottleneck,
then long-ish lengths of 1/2" pipe should be fine, 50 ft max.


Just wondering what I should expect.
--
EA


You have a picture or a link. I want to see what it looks like.
=================================================


http://www.generatorsales.com/order/...Generator.asp?....


additionally modified by them for gasoline, as well. No other options,
except for the propane regulator hose.


Looking at the specs, they specify a 3/8" connection, quite a bit
smaller
than 3/4"
Altho, that diaphram pressure reg. you see attached to the base actually
has
a 3/4" thread, which the company bushes down to 3/8 -- but I think that
3/8"
is just for the propane, and you would use the un-bushed 3/4 for nat
gas....
Now ahm gettin it.... LOL


Note the small overall size of the unit...If you re-locate the pressure
reg,
the actual footprint of the unit is 30 L x 21 H x 16 D -- small indeed.
"Only" 245#, but goddamm, a heavy 245..... holy ****....
Much lower power Generacs et al are the size of a goddamm garden shed!!
And
not honda powered, either.


So it seems I will have to go with 3/4" pipe, which I thought I might
avoid.
So be it.
Let the next storm/outtage come!!
--
EA


Looks like a really nice unit to me. People swear by Honda engines for
generators, compressors, etc. I've never pulled one apart to see for
myself. I don't like Honda's car engines because if you overheat them
they have no material in the head and the head warps. Very easy to do
if an electric fan breaks or shorts. As soon as you notice it, it's
too late. I stick with GM / GMC trucks now. Obviously this isn't an
issue here. Just wondering what makes the Honda engines for this stuff
so good that people rave about them. Probably cast and machined very
well with a lot of attention to detail.
================================================== =====


That, and that the other engines that Generac et al uses are crappy, lot
of
complaints.
Briggs&Stratton generators ought to have an OK engine, don't know about
Kohler and other brands.


What I think is happening is this:
When you buy a generator as a deducated standby back up generator for a
house, these companies are *banking* on the fact that in the next 10
years,
you will run the generator a whole 50 hours. So that's what they build the
engine for. And mebbe not even that.


Otoh, if you buy a *multi-purpose* unit like mine, they proly account for
the fact that you will be beating the **** out of the unit with lots of
use,
and make it stronger. Ergo, the Honder engine.


This Maine company doesn't manufacture stuff per se, they put these units
together from various suppliers, seems to be OK.
They also modify the Black Max 8,750 W unit for tri-fuel, that you find at
Sam's club (gasoline only) -- which also has a Honda engine.


Generac et al has a lot of bells and whistles, but not intrinsic quality,
as
per the above.
I just went for simple and lotsa power. They're all goddamm noisy, until
you get to water cooled units, Onans, etc. Much bigger $$ tho.
Even a lower rpm jobby air cooled jobby cost substantially more money. Run
of the mill are all 3600 rpm.
--
EA


I agree with your assessment. Sure looks to me like you did your
homework and ended up with quality.
================================================== =

Well, time will tell on the quality. *I chose that company because they
seemed like, well, a *real company* , as opposed to some fukn investment
scheme of a bunch of CPAs and lawyers. *You can actually talk to good ole
boys there.

Much of that homework was a number of very good threads on alt.home.repair
on the whole back up power issue, ranging from types of generators, to
battery/inverter backup, to car-inverter backup. *All have some level of
viability, and I keep a big-azz marine battery/1500W inverter in m'truck
(for other purposes), which, in a pinch, could provide not even 1 kW of
power, but enough for basic basics. *The alternator is the real bottleneck.
We talked about high-output alternators as well, but anything really
practical, power-wise, gets into $$.

That marine battery really came in handy, the other day. *For some reason,
the truck batt was deader'n'a doornail, so basically, I was able to give
myself a jump!!! *Hilarious....

Also, those ahr threads showed that what seems like a good idea, a slam
dunk, often is not.

I think a great solution to power back up would be an option for vehicles
for an *additional* super-high output alternator, that could be "levered in"
to the belt system, when it's needed. *But then, this adds year-round weight
to the car, and it is still gas-dependent. *But mebbe the better option for
some. *And hybrids almost have this solution *built-in*!! *Just not the
right voltages.

Ultimately, a noisy genset is Da Bomb, raw watts-wise, and nat gas makes it
an even more usable strategy, esp. for long outages, or, in Sandy's case,
where gas lines were city-blocks long. *The problem with nat gas is the pita
installation. But another very real advantage to nat gas is not having to
worry about carburetor problems, or old/bad gas, or varnishing. *That
reliability factor is a big biggie.

But a good nat gas installation can equal, double, or even triple the cost
of the unit itself, for a non-diy-er. *Even for a diy-er, it's a fair-sized
pita -- for something that you may NEVER use!!! *Dats the kicker.....

So I most likely over-bought, but with the shop and all, and with Sandy (and
Irene, and that 2011 Halloween nightmare ) just scaring the effing bejeezus
out of me, the peace of mind will hopefully be worth it.
They are saying Sandy knocked out power for 8 million people, many of them
for WEEKS, and that Halloween snowstorm knocked out power for a few million,
and many in CT were without power for a MONTH, in NJ for a cupla weeks.
Just too much bull**** around here now.... We're even having *tornadoes*
touch down!!!! * goodgawd....
--
EA


Huge price savings over the diesel units. Much lighter. Are you going
to try and run your garage shop with it or just your house?