Ontwerpgedrag van Blow off Valve in het Local Government Information Model

Question

<\/HEAD> Het ESRI Local Government Information Model verwacht dat blow offs zich bevinden in hun wControlValve feature class, wat betekent dat ze een drukregelmechanisme hebben (automatisch, niet handmatig bediend). In ons District worden blow offs handmatig bediend voor spoeling. Ze verschillen van luchtontlastingskleppen, die 2automatisch2 zijn.<\/P> Vanuit het perspectief van geometrische netwerkanalyse, moeten 2blow offs2 en de klep die we handmatig openen om stroming door de uitlaat toe te laten gescheiden worden in het schema? Bijvoorbeeld voor spoelvolgorde-analyse?<\/P> Momenteel wordt het blow off 2apparaat2 in de put weergegeven door een enkele GIS asset. Dit omvat de uitlaat en een geïntegreerde klep die handmatig<\/EM> bediend moet worden. Deze klep is gespecificeerd als een Ball valve in onze District-standaarden, maar sommige oude blow offs hebben geïntegreerde gate valves.<\/P> Om rekening te houden met de handmatige bediening van de klep en de automatische werking van de blow off-uitlaat, moeten we de huidige blow offs migreren naar zowel de wControlValve feature class als piControlValveType 2Blowoff2, en naar de wSystemValve feature class als ValveType 2Ball2? We zouden waarschijnlijk de SystemValve willen markeren als een blowoff valve, net zoals de Hydrant valves momenteel gemarkeerd zijn in de LGIM.<\/P> Dit kan nog steeds topologiefouten veroorzaken, omdat ze geometrisch samenvallen. Kunnen we dit oplossen door elke ControlValve blow off 0.1' te verplaatsen in tegengestelde richting van de dichtstbijzijnde hoofdleiding? Dan zouden ze altijd 2downstream2 van de klep zijn, automatisch werken, maar geen stroming ontvangen tenzij de 2upstream2 SystemValve geopend is.<\/SPAN><\/P><\/P>Alle feedback over hoe andere waterbedrijven hiermee omgaan wordt gewaardeerd.<\/SPAN><\/P><\/P>Dank u,<\/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?