Blow off Valve entworfenes Verhalten im Local Government Information Model

Question

<\/HEAD> Das ESRI Local Government Information Model erwartet, dass blow offs in ihrer wControlValve Feature-Klasse sind, was bedeutet, dass sie einen Druckregelmechanismus haben (automatisch, nicht manuell bedient). In unserem District werden blow offs manuell zum Spülen betrieben. Sie unterscheiden sich von air-release valves, die "automatisch" sind.<\/P> Aus der Sicht der geometrischen Netzwerkanalyse sollten "blow offs" und das Ventil, das wir manuell öffnen, um den Durchfluss durch den Auslass zu ermöglichen, im Schema getrennt werden? Zum Beispiel für die Analyse der Spülsequenz?<\/P> Derzeit wird das blow off "Gerät" im Schacht durch ein einzelnes GIS-Asset dargestellt. Dies umfasst den Auslass und ein integriertes Ventil, das manuell<\/EM> bedient werden muss. Dieses Ventil ist in unseren District-Standards als Kugelhahn spezifiziert, aber einige alte blow offs haben integrierte Schieberventile.<\/P> Um die manuelle Bedienung des Ventils und die automatische Bedienung des blow off Auslasses zu berücksichtigen, sollten wir die aktuellen blow offs sowohl in die wControlValve Feature-Klasse als piControlValveType "Blowoff" als auch in die wSystemValve Feature-Klasse als ValveType "Ball" migrieren? Wir würden wahrscheinlich das SystemValve als blowoff valve kennzeichnen wollen, ähnlich wie die Hydrant valves derzeit im LGIM gekennzeichnet sind.<\/P> Dies könnte immer noch Topologiefehler verursachen, da sie geometrisch übereinstimmen. Könnten wir dies berücksichtigen, indem wir jeden ControlValve blow off 0,1' entgegengesetzt zur Richtung des nächstgelegenen Hauptrohrs verschieben? Dann wären sie immer "downstream" des Ventils, würden automatisch arbeiten, erhielten aber keinen Durchfluss, es sei denn, das "upstream" SystemValve wird geöffnet.<\/SPAN><\/P><\/P>Jegliches Feedback dazu, wie andere water utilities dies handhaben, wäre sehr willkommen.<\/SPAN><\/P><\/P>Vielen Dank,<\/SPAN><\/P><\/P>Joe Bryant<\/SPAN><\/P>GIS Specialist<\/SPAN><\/P>Carmichael Water District<\/SPAN><\/P><\/BODY><\/HTML>

JoeBryant2 · Answer

Thanks for your assistance, Michael (and Maria).

Currently we don't need much detail - the location of the vault lid, which dead end it is attached to, and the fact that it is a "blow off" seems to be sufficient. We wouldn't ever replace just the valve part of the blow off if it was faulty - we would replace the whole device. Our current spec calls for the blow-off device to have an integral ball valve that we manually open for flushing (it is normally closed; not automatic or pressure controlled). We do have older blow offs with gate valves, but the valve type is not information we are using currently. I assume the guys can tell in the field what type of valve they are operating for flushing and can adjust to prevent water hammer. I also assume you wouldn't ever "throttle" a blow off - you'd want it full-open for flushing. But again, there could be exceptions.

We are not currently linking these blow off assets from the GIS to a separate asset management system, but may do so in the future, although it would probably just be from newly stocked and installed assets forward. And again, there would likely be one single inventory number for the blow off device with an integrated ball valve as that is how they are ordered.

In our LGIM migration we decided we want to stick to the schema as close as possible so that most templates are "plug and play". Currently we decided to use the wControlValve feature class with a type of "blow off" to be consistent. But we could create a new wSystemValve type in the future as you mentioned.

I think I understand that the geometric network won't be affected by either choice, as it is best practice to only assign "sources" and not "sinks" in a pressurized pipe network. I am mainly wondering how these blow offs are being accounted for in hydraulic modelling applications like Innovyse InfoWaterPro. I would like to be able to run analysis to improve our unidirectional flushing methods in the future. The QRY for flushing devices would be slightly simpler if the hydrants and the blow offs were in the same feature class. But if this is accounted for we will adjust our model to fit.

Thanks again.

MikeMillerGIS · Answer

Joe,

What level of detail do you need on your manual blows?  Do you need to know they type of valve?  Do you need to map the valve to your CMMS?  Could you add a new type of Manual Blow off to the control valves and would this be enough?  I do not feel we ever properly models blow offs as there are regional differences and variations of the devices.  It would be good to understand all the different variations so we can include these in the utility network model we are working on.

Anonymous User · Answer

Michael Miller‌, would you know what other utilities are doing in this case?