Modeling Open surge tank

Question

Good Morning 
 
 I have such surge tank to be used in my system at high point. how can i model such type in water hammer?? 
 
 PDF 
 At th begining the tank will be filled from the bypass pipe from 216m where the check valve is closed. during transient vacum cused by downsugbcheck valve will be opened and water start drop to the system to reduce the negative pressure ( it is a one way surge ) 
 
 Please advise with the appropriate way of modeling 
 
 Many thanks & Regards 
 
 bushra

Jesse Dringoli · Answer

Hi Bushra, 
 You can model this in HAMMER using the surge tank element configured as one-way (by selecting "true" for the property "has check valve?".) 
 With this, the hydraulic grade at the surge tank can be greater than the water surface elevation, as the inlet check valve and bypass float valve will be closed. When the HGL below the water surface elevation during a transient event, the check valve will open and water will flow from the surge tank into the system. 
 See more in the following article in our Wiki: Modeling Reference - Surge Tanks