On 06-Sep-17 05:57 PM, Moritz wrote:
Hi all.
I'm back from vacation and see that there was a huge progress in the
proposal.
And there seems to be a consensus for grouping all things where
firefighters can attach their pump under emergency=fire_hydrant.
Where there is a dedicated pipe/hydrant. Where there is a 'Static Water
Supply' then there are usually no formal fittings of any description.
But I think there are some issues left:
# Fire Water wells
A pipe connected not to a pond but to the groundwater.
Should be
water_source=groundwater
How to tag the water level (distance between water level and ground
level)?
water_level=6 (in meters) ?
Also there are water wells which have a water level below approx 8 m
and due to physics there is an additional pump needed. This pump is
integrated in the
water well at water level and is either driven by electricity or
external applied water pressure.
Humm water level is usually taken as the height reached by the water,
from the bottom of a well/dam/tank.
If you are sucking then you might get to the bottom .. so you would need
equipment to get to the very base of the water.
Must be a better term for this parameter? You want the dimension from
the pump point to the minimum (most distant height) water level.
The pressure tag is not suitable for it as the water does not need to
be sucked out and the pressure is not known.
But the information is important for fire fighters to know which
additional equipment they need.
pump_type=bilge_pump|electric_pump|none ?
# Water tanks
water_source=water_tank
The capacity of the water_tank should also be attached to the hydrant.
water_volume=small|medium|large|# (small 75–150 m^3, medium) 150–300
m^3 and large>300 m^3 or numeric value).
# Fire water pond
water_volume=# (numeric value in m^3).
Around me capacity is stated in litres? So this could be a optional unit.
I'd rather not see a small|medium|large value. But I suppose some one
will want it, though the numbers for hte differences will probably be
argued over. Place the numeric value first and state it as a preference?
# fire_hydrant:class=*
Should be clarified what AA, A, B, C means.
Cheers
Moritz
Am 2017-09-06 00:24, schrieb Viking:
Hi all.
@Marc
and is this tag well used? I am not able to judge whether values are
realistic
Well, as in every tag, there are wrong values. But now, with a more
clear description on the wiki, there will be less errors and future
corrections will be possible.
Anyway all values of fire_hydrant:diameter=# should go in the new tag
diameter=#, or whatever else we choose.
what do others think? if somebody find it is not appropriate, I
think that it would be desirable to split out the "meaning change"
to validate the rest of the proposal.
At this point, after the discussion of pros and cons, I think that the
"meaning change" has no more sense.
@Francois:
fire_hydrant:count=# --> devices=#
+1 I'm against grouping more than one hydrant one a node, but if we
want to keep this possibility, devices=# for me is better.
A pressurized hydrant : emergency=fire_hydrant + optional
water_source=network + even more optional pressure=*
A pillar connected to a water tank where water can be pumped from :
emergency=fire_hydrant + water_source=water_tank + pressure=0
A pipe going permanently in a river or a pond where water can be
pumped from :
emergency=fire_hydrant + water_source=pond + pressure=0
+1
@Martin:
unfortunately this is not yet defined unambiguously
In hydraulics in general, the diameter is the nominal one [0] that is
related but not equal to the inner diameter. On hydrants in
particular, the number that is die-casted on them, is the nominal
diameter of the undergound junction towards the water network.
Also couplings diameters are always nominal diameters of the threads
[1].
Maybe it is enough to document on the wiki that when diameter=* is
used for hydrants, it is referred to nominal diameter?
Not sure about pressure=0 though, shouldn't that be 1? The wiki
mentions also "suction" for dry hydrants
In hydraulics, pressure normally is measured relatively to atmospheric
pressure. So 0 is correct. However, to avoid misunderstandings, we can
keep pressure=suction for these cases.
Best regards,
Alberto
[0] https://en.wikipedia.org/wiki/Nominal_Pipe_Size
[1] https://en.wikipedia.org/wiki/ISO_metric_screw_thread
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