Fire Hose Testing
Ernie
in our local dept. We currently test all hose on an annual basis. All hose
is tested at 200 psi static pressure. Here is the discussion: If you are
testing two different diameter hose lines at the same time connected to a
wye, a) is the pressure going to be higher in the smaller diameter line? b)
or is the test pressure going to be the same? Is there any documentation to
support either a or b?
Thanks for any help.
J. R. Ford
wrote:
If both hoses are capped the pressure will eventually equalize. You
would need to have a gate or nozzle and a gauged fitting on the end of
the hose with the lower test pressure. The wye can then be gated to
the point where the ball of the valve is just slightly cracked. Then
slightly open the valve or nozzle on the end of the hose to maintain
the desired pressure. It will take a little juggling but can be don
and would probably save some time once you have the hang of it.
Tom Wilson
Ernie <e.re...@worldnet.att.net> wrote in message
news:HaHH4.3491$YB4.2...@bgtnsc05-news.ops.worldnet.att.net...
> Perhaps someone in this group could help settle a disagreement we are
having
> in our local dept. We currently test all hose on an annual basis. All
hose
> is tested at 200 psi static pressure. Here is the discussion: If you are
> testing two different diameter hose lines at the same time connected to a
> wye, a) is the pressure going to be higher in the smaller diameter line?
b)
> or is the test pressure going to be the same? Is there any documentation
to
> support either a or b?
>
> Thanks for any help.
>
pressure behind the pump is relative.
Arvid F Sorsdahl
hose to reach the static pressure but only a second or two. For proof put a
gauge on the end of each hose.
Bbarryfire
all directions in a closed system with no flow the only thing you are
changing with different hose sizes is the shape of the container.
Arvid F Sorsdahl
the large hose will reach maximum pressure first----if the two hose lays are the
same length.---sort of splitting hairs---for all practical applications the
pressures will be the same.
Scott Aleckson
> Perhaps someone in this group could help settle a disagreement we are having
> in our local dept. We currently test all hose on an annual basis. All hose
> is tested at 200 psi static pressure. Here is the discussion: If you are
> testing two different diameter hose lines at the same time connected to a
> wye, a) is the pressure going to be higher in the smaller diameter line? b)
> or is the test pressure going to be the same? Is there any documentation to
> support either a or b?
>
> Thanks for any help.
As for your question, the pressures will be equal during a static test. There
is no water flowing and pressure will be equal throughout the system. The
documentation on this hydraulic principle is readily available in your IFSTA
manuals on Pumping Apparatus, Water Supply, and Fire Streams, just to name a
couple sources.
The more important point you bring up is that you need to check NFPA 1962 (Use,
Care, and Service Testing of Fire Hose Including Couplings and Nozzles) and test
your hose to the required pressures. Only supply lines (LDH) get tested to 200
psi. A test to 200 psi on attack lines is inadequate as you may easily be
operating above this pressure on a fire scene. You should be testing to at
least 300 psi on your attack lines and most newer hose is recommended to be
tested at even higher pressures. Check with your hose manufacturer for the
correct testing pressures and reference NFPA 1962 as well.
Sean Bennett
Our Service uses non percolating rubber lined hoses, varying in size from
38mm (1 1/2 inch) to 90mm (3 1/2 inch).
This hose has differing pressure classes:
1. L -Low, - Max working pressure - 1000 kpa (140 psi),
2. M - Medium, - Max working pressure - 1400 kpa (200 psi), and
3. H - High, - Max working pressure - 2100 kpa (300 psi).
All hose is marked with a letter denoting which class it belongs in eg "M"
for Medium. Any hose that does not have a class indicator, is classed as a
Low pressure hose. Most of the hose we now use is "H" Class. When tested,
hoses are pressurised to their maximum working pressure for a period of not
less than 3 minutes.
As stated in other responses, one of the characteristics of the centrifugal
pump is that "at any given speed, when there is no flow the pressure is at a
maximum". Therefore the pressure will be the same in the attached hose with
the ends capped (a closed branch/nozzle).
According to our regulating standards, we can test up to 3 lengths of hose
on one line, or two lengths of hose on two lines, simultaneously. And
really, it should not matter if the hoses are of differing Internal
Diameters (ID) as long as they were of the same class.
You should check with your regulating authorities and hose manufacturers for
the correct pressure testing procedures and pressures for your particular
brand of delivery lay flat hose.
Wishing you all the best,
Benno
A
"Ernie" <e.re...@worldnet.att.net> wrote in message
news:HaHH4.3491$YB4.2...@bgtnsc05-news.ops.worldnet.att.net...
Ernie
useful.
Thanks again.
"Sean Bennett" <ben...@powerup.com.au> wrote in message
news:38efee4a@grissom...
John T. Stevenson
>testing two different diameter hose lines at the same time connected to a
>wye, a) is the pressure going to be higher in the smaller diameter line? b)
>or is the test pressure going to be the same? Is there any documentation
to
>support either a or b?
We are talking static pressure, so it will be the same throughout.
You can probably find some indirect documentation for this in the IFSTA book
on Water Systems - it isn't speaking specifically of hose, but of water
pressure in general.
John Stevenson
Captain
Port Everglades
Timhoerner
the setup regardless of hose size.
Burton W. Phelps
throughout (no water flowing).
J. R. Ford <jrf...@atlascomm.net> wrote in message
news:0uhuesoqp45j9uevq...@4ax.com...
> On Sat, 08 Apr 2000 14:16:07 GMT, "Ernie" <e.re...@worldnet.att.net>
> wrote:
>
> >Perhaps someone in this group could help settle a disagreement we are
having
> >in our local dept. We currently test all hose on an annual basis. All
hose
> >is tested at 200 psi static pressure. Here is the discussion: If you
are
> >testing two different diameter hose lines at the same time connected to a
> >wye, a) is the pressure going to be higher in the smaller diameter line?
b)
> >or is the test pressure going to be the same? Is there any documentation
to
> >support either a or b?
> >
Alan Beem
would assume that you are not doing during pressure testing) pressure will
be equal in all directions.
You can probably find written documentation proving this in any High School
level physics book.
"Burton W. Phelps" <inc...@crosslink.net> wrote in message
news:95537810...@pizza.crosslink.net...
Gerard & ciedre
>the large hose will reach maximum pressure first----if the two hose lays are the
>same length.---sort of splitting hairs---for all practical applications the
>pressures will be the same.
>
is 1 vessel with 2 "legs" on it, if there were more pressure in the
large hose, it would push the excess pressure towards the smaller
hose.. and since pressure loss is directly related to volume, the
amount would not even be registrable.. what would be more noticably
would be and slope of elevation the hose is on...