Bladder Type Surge Vessel

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Bladder Type Surge Vessel

ERGIL Bladder Surge Vessel (also called hammer tank, hydropneumatic surge control vessel, or expansion tank) is designed to control the surge with a butyl rubber inside the vessel. In order to provide the required elasticity to push the water into the system following a pump trip, the calculation of pre-charge pressure will be vital. If there is no contact between the compressed air and the water, there will be no dissolution. In this way, there will be no need for a permanent regulation system including compressors, etc. When the vessel has been stimulated and corrected the pre-charge has been introduced, the vessel will operate automatically, depressurizing once called upon and refilling with the return waves until naturally reaching its steady-state balance.

The internal bladder is often made from high tensile rubber with or without reinforcements, in Neoprene, Nitrile (Buna-N), Food Grade Butyl,  Hypalon rubber, or expanded to fit the whole vessel. The bladders are complying with a flange at the top as per the customer’s vessel details.

Pressure Vacuum Valve production certificates


Vertical or horizontal types are available.
A bladder is fixed to the outlet/inlet connection orifice located on the bottom or the side of the vessel.
The bladder is designed so it can expand to the full size of the vessel. This allows for greater drawdown volumes and less stress on the bladder.
The air is trapped in the space between the outside of the bladder and the wall of the vessel. Therefore the liquid is not in contact with the steel walls of the vessel.
Depending on the level of cubage in the tank it is possible to design by using minimum 3,  maximum 4 legs as optional.
Service Pressures Range: up to 25bar
Capacities are available from 3000lt to 70000lt

Surge Vessel Models