Pressure tanks are important components of pressurised booster supply systems where automatic pumped water supply is provided by means of pressure switch controlled pumps. The tanks have two functions; to cushion pressure surges as the pump starts and stops and also to provide a drainage supply into the system to control pump cycling
VAREM pressure tanks have been specially designed for pressurised booster installations and are also suitable for fire fighting and irrigation systems. The design incorporates a replaceable butyl rubber membrane which offers the following features:-
VAREM pressure tanks are quality products approved by a number of international standards organizations. They are the ideal solution for all pressured water supply installations and if properly selected will provide many years of maintenance free operation.
Pressure Tank Sizing Guide
Correct tank sizing is important and is determined by the system flow rate and pump start and stop pressure settings
Sizing must be based upon the system flow at which the maximum cycle frequency occurs. As a rule of thumb this can be taken as 65% of the flow at pump stop pressure.
Required draining volume is then the maximum cycle frequency flow divided by twice the specified maximum number of cycles per hour. Generally 60 cycles per hour is considered acceptable. Tank size selected is then that nearest to the volume required. Drainage volume is as follows:-
|Tank Pre-charge (Bar)||1.35||1.65||1.85||2.35||2.35||2.83||3.85||4.85|
|Pump Start Pressure (Bar)||1.5||1.8||2.0||2.5||2.5||3.0||4.0||5.0|
|Pump Stop Pressure (Bar)||2.5||3.0||3.5||4.0||4.5||4.5||6.0||7.5|
|Tank Model||Drainage Volume (Litres)|
|KS (24 Litres)||6||7||7||7||8||6||7||7|
Note that when specifying pressure systems the following is important:
Pump Stop Pressure = 4.5, Bar Stop Flow = 11m3/hr
Pump Start Pressure = 2.5 Bar Start Flow = 16m3/hr
System flow at maximum cycle frequency = 65% of Pump Stop Flow = 0.65x11=7.2m3 /hr or 7200l/hr Max Cycle frequency = 60cycles/hr therefore required drainage volume = 7200/60x2=60 litres
From table 100 litre tank has drainage volume of 34 litres at defined pressures. 300 litre tank has drainage volume of 103 litres at defined pressures.
Therefore select either 2x100 litre tanks (68 litres drainage volume) or 1x300 litre tank (103 litres drainage volume).
|Max Pressure (Bar)||8|
|Dimensions (mm) - DN||360|
|Dimensions (mm) - H||335|
|Dimensions (mm) - H1||-|
|Gross Weight (kg)||6|
|Pack Volume (m3)||0.047|