Local Government Information ModelにおけるBlow off Valveの設計動作

Question

<\/HEAD> ESRI Local Government Information Modelでは、blow offsはwControlValveフィーチャクラスに含まれることが期待されており、これは圧力制御機構を持つ（手動操作ではなく自動である）ことを意味します。私たちのDistrictでは、blow offsは洗浄のために手動で操作されます。これらは「automatic」であるair-release valvesとは異なります。<\/P> 幾何学的ネットワーク解析の観点から、「blow offs」と流出口を通じて流れを許可するために手動で開くバルブはスキーマ上で分けるべきでしょうか？例えば、洗浄シーケンス解析のために？<\/P> 現在、vault内のblow off「デバイス」は単一のGIS資産として表現されています。これには流出口と手動で操作しなければならない統合バルブが含まれます。このバルブは私たちのDistrict標準ではBall valveとして仕様されていますが、古いblow offsには統合されたgate valvesもあります。<\/P> バルブの手動操作とblow off出口の自動操作を考慮するために、現在のblow offsをwControlValveフィーチャクラスのpiControlValveType「Blowoff」として、またwSystemValveフィーチャクラスのValveType「Ball」として移行すべきでしょうか？SystemValveをblowoff valveとしてフラグ付けしたいと思います。これはLGIMで現在Hydrant valvesがフラグ付けされている方法に似ています。<\/P> これでも幾何学的に重複しているためトポロジーエラーが発生する可能性があります。これを解決するために、すべてのControlValve blow offを最寄りのmainとは反対方向に0.1フィート移動させることは可能でしょうか？そうすれば常にバルブの「下流」に位置し、自動的に作動しますが、「上流」のSystemValveが開かれない限り流れは受けません。<\/SPAN><\/P><\/P>他の水道事業体がこれをどのように扱っているかについてのフィードバックをいただけると幸いです。<\/SPAN><\/P><\/P>よろしくお願いいたします。<\/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?