• Pump start-up scenario (HAMMER) with air valve at highest point

    Good morning, I'm modelling a pumped sewer with a double acting air valve at the highest point and a final free discharge (D2A element) in HAMMER. When running a pump start scenario, the last stretch of the pipe is obviously empty (the water previously…
  • Does Hammer calculate the head loss across an air valve when a headloss coefficient is provided as input?

    Hello, Does Hammer calculate the head loss across an air valve when a headloss coefficient is provided as input? InfoSurge can calculate this headloss across an air valve, and it would be great if Hammer can have this capability. In my model, it is…
  • Modelling Combination Air Valves

    I'm modelling an existing pipeline using Hammer Connect Edition 10.03.05.05 with 2" combination air valves (see linked data sheet below). /cfs-file/__key/communityserver-discussions-components-files/5925/Air-Valve-Data-Sheet.pdf Are these air valves…
  • inserimento air valve dopo evento transitorio arresto pompa (ho bisogno di aiuto)

    buongiorno, dopo tante domande siamo quasi arrivati alla fine del problema. Dopo aver calcolato un'analisi transitoria di arresto di una pompa con numero di giri variabile ho problemi relativi alla cavitazione e quindi ho inserito dove ho questi problemi…
  • Hammer - Air Valves continuously intake air

    Hi All, I am not sure if I am interpreting my results correctly and would like to hear second opinion. I am modelling a sewage rising main in Hammer 10.03.. The rising main is approx. 3.3km long and the pipe material is mostly OD 160mm HDPE SDR17…
  • Complex Parallel Force main Modeling

    I have a rather complex force main system we are trying to model and I just want some help confirming that it is set up appropriately. A short summary is this: - Parallel 30” and 24” force mains from a lift station to a WWTP - Trying to model full and…
  • System Disconnection at Air Valve

    I have a water force main in WaterCAD that I am modelling, and I have a high point along the main. To get the pump to recognize the high point, I have placed an air valve right before this junction at the same elevation with the 'Treat as Junction' field…
  • Is air valve sizing/placement dependent upon material of the pipeline?

    Hi, We had a problem in our distribution network of increased pipe breaks, when a large portion of the pipelines was changed from Asbestos Cement to HDPE. With AC, there was no pipe break recorded for over maybe 10 years. With HDPE we started getting…
  • Syphon breaker modeling in hammer

    How to model a syphon breaker in hammer , a syphon breaker valve is located at high point and open only when the flow is reversed to admit air to the system
  • STEADY STATE, AIR VALVE,HYDROPNEUMATIC TANK (BLADDER), Sudden closure of NRV

    1. How to perform steady state condition in Hammer & how could it be reported? 2. While performing the analysis considering Hydropneumatic tank keeping the Junction as true, pipeline experience negative pressure. But, if the same same option is changed…
  • AIR VAVLES

    If I used VACUUM BREAKER to protect My pipe from negative Protection Due to Pump Shut Down ... How can i know the Amount Of Air what entered the pipe ?? And How Can i KNOW that this amount of Air has got out from my Pipe and can it get out through the…
  • "Base" "Cannot solve network hydraulic equations." HAMMER

    Hi I have a question... I'm simulating a line of driving with a pumping system and then occurs by gravity to reach a storage tank therefore the there are sudden change in elevations therefore placed air ejector valves. but at the time of model does…
  • Negative Pressures in Pipe

    My model consists of a reservoir from a higher elevation supplying water to two tanks at a lower elevation. The pipe leading to the tanks keeps going to a negative pressure despite the inclusion of air valves. How can I correct this?
  • How to relate double/triple acting air valve to the ones in reality for surge analysis?

    Hi all, I have some questions about configuring air valves in the model for transient analysis for pump shutdown events. Double acting air valves: In reality, the double acting air valve in reality acts like the below picture to my understanding…
  • RE: Unexplainable Results of Modeling AVs in Hammer

    Hi Ahmed, Re: "may I consider this velocity as a software related assumption, and simply ignore the velocity diagram as long as the pressure envelope along the pipeline is acceptable?" This is something that you will need to decide based on the assumptions…
  • RE: Unexplainable Results of Modeling AVs in Hammer

    The velocity profile shows the maximum (red line) and minimum (green line) velocity over the length of the profile. If you have the calculation option set to generate animation data, you can navigate through time and see the "current" HGL (black line…
  • RE: Static Head and Hydraulic Grade - pumping over high point.

    Here are some related articles on the use of the air valve node element in this situation (item 2 in Tom's list): SewerCAD: http://communities.bentley.com/Products/Hydraulics___Hydrology/w/Hydraulics_and_Hydrology__Wiki/modeling-force-mains-with-air…
  • Re: HOW MODEL COMBINATION AIR VALVES?

    Cesar, The benefit of using a modeling program such as HAMMER is that you can try out all the different types of equipment (and configuration of said equipment, such as the air inflow/outflow orifices sizes) and compare the results to see which…
  • Re: How should i enter data for air valves?

    Why do you think the results are not real? I would recommend animating your profile path to see if air pocket collapse is occuring - this phenomenon can indeed cause a very high upsurge. I cannot say for sure if your data was entered correctly…
  • Re: HOW MODEL COMBINATION AIR VALVES?

    If someone wants to model only the cascading flow downstream of an air-valve; that is, the transitional pressure to gravity type flow that might set up in a gravity trunk main or a sewer forcemain, they should take a look at the new WaterGEMS/WaterCAD…
  • Re: Vacuum pressures

    Hello Mohamad, Air valves are usually installed at high points in system and sometimes serve two purposes. First, they will release trapped air that accumulates at high points. Also they can open up to admit air into the system during a transient event…
  • Re: HOW MODEL COMBINATION AIR VALVES?

    Cesar, Could you describe the situation you are trying to model? Perhaps a pump shutdown? What is at the downstream end of your system? (reservoir? Demand?) Do you have any storage tanks? If you are modeling a pump shutdown scenario, you…
  • Re: Submerged Orifice(s) in PIping - WaterCAD V8i

    The intermediate high points are important when you first get the flow moving (for example, the pump would 'see' a high point when it is first pushing water over that point). After that though, it becomes a bit tricky. If you have vacuum breakers at…
  • Re: Air Valves - Vacuum Breaker Problem In Hammer

    Hello, As far as I know, there is no way to change this. Air valves in HAMMER will "open" when the hydraulic grade drops below the physical elevation of the air valve (the "elevation" field in the physical section of the properties). Like you said…
  • Re: How should i enter data for air valves?

    Hello Cesar, I assume you're referring to Bentley HAMMER V8i. When using an air valve, you must be careful to size it such that air pocket collapse doesn't cause worse pressures than without the valve at all. Animate your profile path in…