DESCRIPTION
EUROSAFE Bladder Type Foam Proportioning Unit (Bladder Tank) is provided for accurate foam proportioning of the foam concentrate with the fire- water over a wide range of flow.
WORKING PRINCIPLE
EUROSAFE Bladder tanks consist of the following main components i.e. Foam Vessel, Foam Bladder, Foam Proportioner, Water Piping, Foam Piping, Vent & Drain Valves and Level Indicator.
During operation the water is charged into the bladder tank between the vessel wall and the bladder to the inlet water pressure. Bladder transfers this water pressure to the foam concentrate stored inside the bladder, this causes pressurisation of the foam concentrate.
Pressurized foam concentrate is delivered to the foam concentrate inlet of the foam proportioner. A foam concentrate orifice is provided for accurate mixing of the foam concentrate into the fire-water.
The metering pressure drop is created in the foam proportioner which causes the foam concentrate to flow into the fire water stream.
INSTALLATION
- Unpack the materials and identify the materials as per the packing list.
- Check the material for the physical fitness and for any mechanical damage if any.Check the foundation dimensions as per the foundation drawing.Lift the foam vessel and place on the foundation.Carry out the grouting and anchoring of the bladder tank supports as per the standard engineering practice.Install the foam proportioner in the piping (Ignore if already installed).Install the water piping and the valves (Ignore if already installed).Install the foam piping and the valves (Ignore if already installed).
FIRST FILLING OF FOAM CONCENTRATE
- Ensure that all the valves on the bladder tank are in closed position.
- Open Valve V4 (bladder vent valve) & V3 (vessel vent valve).
- Open Valve V6 (vessel drain valve).
- Connect the water supply to Valve V6 (vessel drain valve).
- Open the valve V6 (vessel drain valve) to charge the water on the outside of the bladder and inside of the vessel wall (water filling pressure should not be greater than 3 psi)
- Charge the water until discharge of water is observed through valve V3 (vessel vent valve).
- Close the Valve V6 (vessel drain valve).
- Connect the foam filling pump discharge pipe to Valve V7B (bladder drain valve).
- Open the Valve V7A & V7B (bladder drain valve) to charge the foam con- centrate in the foambladder.
- During filling operation if foam concentrate discharge is observed through valve V4 (bladder vent valve), open the valve partially V6 (vessel drain valve) to drain the water from the bladder tank during the filling opera- tion.
- Continue the filling operation till the required quantity of the foam concen- trate is filled into the bladder tank.
- After filling, close the valve V7A, V7B, V3 & V4.
- Open the Valve V6 (vessel drain valve) to charge the water in the bladder tank.
- Open the Valve V4 (Bladder Vent Valve) to vent the air in the bladder. Close the valve on the discharge of the foam concentrate from Valve V4 (bladder vent valve).Close the Valve V6 (vessel drain valve).
- Disconnect the water supply from the Valve V6 (vessel drain valve).
OPERATION
MANUAL OPERATION WITHOUT FOAM CONCENTRATE CONTROL VALVE
- Open the main water supply isolation valve to the Bladder tank provided on the water inlet side of the foam proportioner.
- Open Valve V1 (water charging valve) to charge the water in the bladder tank.Open Valve V2 (foam supply valve) to supply the foam concentrate to the foam proportioner / ratio controller.Foam proportioner / ratio controller will deliver the foam solution to the foam system.
AUTOMATIC OPERATION WITH FOAM CONCENTRATE CONTROL VALVE
- Open the main water supply isolation valve to the Bladder tank provided on the water inlet side of the foam proportioner.
- Valve V1 (water charging valve) shall be in open position.Valve V2 (foam supply valve) will be automatically opened once the hy- draulic cylinders get operated which will supply foam concentrate to the foam proportioner.Foam proportioner / ratio controller will deliver the foam solution to the foam system.
AFTER OPERATION
- Close the valve V2 (foam supply valve) to stop the foam concentrate supply to the foamproportioner.
- Flush the foam solution piping till discharge of water is observed through the discharge device.
- Close the main water supply isolation valve.
- Open the valve V3 (vessel vent valve) to depressurise the bladder tank.
REFILLING OF FOAM CONCENTRATE
- Ensure that all the valves on the bladder tank are in closed position.
- Open valve V3 (vessel vent valve) and valve V4 (bladder vent valve).
- Connect the foam filling pump to the valve V7B (bladder drain valve).
- Open the valve V7A & V7B (bladder drain valve) to charge the foam con- centrate in the foambladder.
- It is always advised to keep the bladder tank filled to its rated capacity at all times
CONCENTRATE LEVEL CHECK
- Open the valve V3 (vessel vent valve) and V4 (bladder vent valve).
- Open the valve V6 (vessel drain valve) to drain the water from outside of the bladder.
- Open the valve V7A (bladder drain valve)
- Open the valve V8 (level indicator valve) to check the level of the foam concentrate in the bladder tank.
- Close the valve V8 (level indicator valve) and open the valve V7B (level in- dicator drain valve) to drain the foam concentrate from the level indicator.
- Connect the water charging connection to valve V6 (vessel drain valve).
- Charge the water in the bladder tank till water discharge is observed through valve V3 (vessel vent valve).
- Close valve V6 (vessel drain valve) and valve V3 (vessel vent valve).
- Disconnect the water charging connection from valve V6 (vessel drain valve).
MAINTENANCE
- Check the operation position of the valves on a weekly basis.
- Operate the system with water on quarterly basis.
- Operate the system with foam on semi-annual basis.
NOTICE
Since the lack of a bladder or its damages determines a decrease of performance of the foam fire fighting system sereved by the bladder tank, it is highly recommended that the end user always keeps a spare bladder readily available for replacement within 24 hours.
CAUTION
- To avoid damaging the bladder, DO NOT perform welding on the tank bo- dy.
- Do not carry out the hydrostatic test with bladder mounted inside the tank, as it may damage the elastomeric bladder.
- To avoid bladder damages the installation of a strainer upstream of the tank is recommended.
- Lifting lugs are designed to lift the tank empty.