[Tagging] Fire hydrants vs suction_point

[Warin]

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
>>
>>
>>
>>
>>
>> ---
>> Questa e-mail è stata controllata per individuare virus con Avast 
>> antivirus.
>> https://www.avast.com/antivirus
>>
>>