Bladder type Surge vessel

Hello Bushra,

Could you please elaborate your query?

Whether there is air in the bladder or water in the bladder and air is in the area between the tank casing and a bladder, depends upon the type of hydropneumatic tank you are provided with. AS explained in the technote referenced it could be two ways depending upon what type of hydro tank you have selected for design i.e. air in the bladder or water in the bladder. 

See related forum discussion about same topic for your reference. 

Modelling a hydropnematic tank with water in bladder (Hammer connect edition)

My question is in general how to deiced wither to put air in side the bladder or water inside. Is there any specific recommendation for that? such as for drinking water bladder shall filled with water & air will be surrounded

Hello Bushra,

As mentioned in the "Bladder" section of the Hydropneumatic Tank Modeling Reference article, the choice of whether you have air-in-bladder or water-in-bladder is not a factor hydraulically for transient modeling in HAMMER, since there is still a certain volume of gas and a gas/pressure relationship that determines the change in pressure due to a change in volume and vice versa.

Since your question is not HAMMER/modeling specific, we may need to rely on other Community members to provide input based on their experiences. I am not personally certain if there are any guidelines for this decision based on the type of water or type of application. I would also recommend reading articles or other case studies on this subject for the pros and cons of each method (air vs. water). You would also want to consider any local regulations, standards and guidelines.

This page from the well-known tank manufacturer Charlatte shows both options and may help with your research.

Being more of an admin/engineer role than in the field but oversee my field guys, our water facilities utilize bladder tanks from Flexcon, Well X Trol, etc.  The bladder fills with water and expands in the chamber that is filled with air.  Most of the tanks are equipped with a shrader valve that allows for the operator to attach an air gauge to determine the pressure of the tank.  Most tanks are precharged from the factory at 35 psi and can vary some which may require adding or removing air to get to the precharge pressure.  Periodic check include checking the pressure not under pressure so typically you would disconnect it from the main pipeline, drain the water off and check.  Before you do, you can take a steel pipe or something hard to bang up and down the tank.  It should sound hollow near the top and solid at the bottom, if a tank is water logged, the tank will sound the same as the bottom. Chances are in that case that the diaphragm is cracked and if that is the case, the tank is disposed of.  Each tank should have an O&M manual to describe the checks you can do on the tank.  Hope this helps.

Being more of an admin/engineer role than in the field but oversee my field guys, our water facilities utilize bladder tanks from Flexcon, Well X Trol, etc.  The bladder fills with water and expands in the chamber that is filled with air.  Most of the tanks are equipped with a shrader valve that allows for the operator to attach an air gauge to determine the pressure of the tank.  Most tanks are precharged from the factory at 35 psi and can vary some which may require adding or removing air to get to the precharge pressure.  Periodic check include checking the pressure not under pressure so typically you would disconnect it from the main pipeline, drain the water off and check.  Before you do, you can take a steel pipe or something hard to bang up and down the tank.  It should sound hollow near the top and solid at the bottom, if a tank is water logged, the tank will sound the same as the bottom. Chances are in that case that the diaphragm is cracked and if that is the case, the tank is disposed of.  Each tank should have an O&M manual to describe the checks you can do on the tank.  Hope this helps.