• STREETER BOOK WORKED EXAMPLE AND HAMMER RESULTS-DIFFERENCES IN MAXIMUM TRANSIENT PRESSURE

    Hello, I found the example 3-1 on the Streeter book "Fluid Transients" (2004) it consist in a pipeline of 600 m length, 0.5 m diameter, Darcy friction factor 0.018, reservoir with 150 m hydraulic grade and a valve that close in 2,3 seconds, following…
  • Behavior of pump in the case of Valve closure is not clear

    I am modelling a system, and one of the scenarios is an emergency shutdown of the flow control valve (FCV) downstream of the pump as shown in the following image: the FCV is modelled as a throttle control valve (TCV) with the properties of the original…
  • MODEL VALVE IN HAMMER

    Hi community, I am a new user of HAMMER software, and I need to study what happens in an upstream pipe of 2.5 m of diameter when a valve is closed suddenly, I have tried to find tutorials on youtube and there are a couple, the majority related with pump…
  • I am New to Water hammer. I want to model water hammer due to valve closure.

    I am New to Water hammer. I want to model water hammer due to valve closure. The pressure line of DN600 is a sub header from a DN1200 pressure main of 6bar. As I didn't know how to introduce pressure without a source, I made the model considering a pump;…
  • Hammer - Issue with results from valve closure on pumping system

    Hi, We have modelled a transient scenario, where a variable speed pump is operating at a fixed head, and 12 downstream isolation valves simultaneously closing linearly over 60 seconds, reducing the flow by 95% (one branch remains open passing 5% of…
  • Modelling of Valve Closure effect

    Hi Guys, I created a model to find best valve closure time in normal operation of a gravity pipeline. I got strange result. Level difference between reservoir and valve is 10m but I got maximum transient pressure of 250m if valve is closed in 2 stage…
  • Valve Closure Modeling - HAMMER

    Hello Forum, I'm working on a model where the transient scenario is developed by a PRV closure. I entered the Operating Rule (A linear closure for now in 0.6 s) and established a User Defined valve because I have the Characteristic Curve. The problem…
  • Water Distribution Network _ Valve Closure

    I have a large water distribution network which is mainly a 600mm water pipeline that feeds 10 different areas (districts) as shown in the attached screenshot. I am doing transient analysis to find out an optimized closure times for the flow control…
  • Re: Top Feed Gravity Dischare Tank

    Hi, I would suggest ending the system at the inlet of the tank using a discharge to atmopshere node element, since the tank itself and downstream elements won't be effected by the valve closure. The Discharge to Atmosphere node can be configured as…
  • problem w/ TCV during transient analysis

    i defined an operational pattern for a TCV to simulate gradual valve throttling, but the transient model yields unexpected results. The pattern starts at 0% relative closure and gradually (in one second intervals) ramps closed (in 10% increments), so…
  • Distribution Sytem Wide Hammer and Transient Analysis of RPZ

    I am attempting to set up a model to demonstrate how a RPZ (Reduced Pressure Principle Backflow Preventer) will respond to Hammer. For those unfamiliar with the operation of an RPZ, I have attached a document which outlines this very well. …
  • Control valve response to transient event

    Is there a way to model the response of a control valve to a transient event beyond manually inputting the transient operational pattern? An example would be what happens to a PSV when the transient pressure drops below the pressure set point.
  • Unusual Flow Results

    I'm getting some unusual results and am unable to find a solution. I'm trying to better calibrate our model near an area where 2 pressure zones meet. I've performed a fire flow analysis and tried to confirm the pressures and flow in that area. A flow…
  • Re: Valve closure (transient) modelling in Hammer

    Hello Sukru, The reason why you see those fields in the Lesson2_WaterGEMS.wtg file is because that file is configured to have user defined initial conditions specified. This is designated by the setting of "true" for the attribute called "Specify…
  • Re: Air valve size

    Hello Mohsen, Without seeing the model or full animation of the profile path, it's hard for me to tell. Generally speaking, air valves can only provide protection against subatmospheric pressure in the direct vicinity of that air valve. So, if the…
  • Re: Modeling a 1.5 second valve closure at Airplane Fueling Nozzle?

    Hello, The pumps are going to operate based on the system conditions (where the pump curve intersects the system head curve.) So, you'll need to "model what you've got" to get the right pump operating point. Meaning, if there aren't FCVs in reality…
  • Re: Modelling with TCV

    Sovan, The table you mentioned defines the valve characteristics, not the closure pattern. Be sure to also define the operating rule, which is the pattern of closure over time. You can also find some advice on modeling TCV closure here: …
  • Valve closure modeling in Hammer

    Hi I am trying to simulate a pumping main from a low elevation sump to a high elevation sump (HES). To simplify the system practically i am planning on using a altitude valve at the HES, so when the HES is filling to top level the altitude valve will…
  • Re: Relative Closure

    Hello, The relative closure is in reference to whatever you'd like it to be. To explain this a bit: basically when you define a custom valve characteristics curve, it is a table of relative closure versus relative discharge coefficient. The relative…