Surge Vessel

ERGIL Surge Vessels is a powerful and user-friendly control system that protects your pipeline systems against waterhammer & pressure transient.

Why do you need surge vessels in your applications?

Surge vessels are important assets in the water treatment process,though incorrect maintenance and management can lead to issues in pipelines costs and the water industry millions every year, causing burst pipes, structural damage, negative pressures and colossal water wastage. Negative pressure directly contravenes Drinking Water Inspectorate (DWI) legislation due to the risk of contamination.


 Negative pressure causes lots of water waste and money                                       Negative pressure failure in pipeline causes oil waste and pollution 

What is a surge vessel?

A surge vessel or water hammer is a standpipe or storage reservoir at the downstream end of a closed aqueduct or feeder or a dam or barrage pipe to absorb sudden rises of pressure, as well as to quickly  provide extra water during brief drop in pressure.


Reowned company understanding of surge system design
Ensures compliance with Product Equipment Directive & ASME regulations
Reduces water leakage
Pipeline fatigue and bursts analyzes
Minimizes risk of contamination in potable water pipes caused by negative pressures
Accommodates variable pumping regimes without dumping compressed air
Improves your company’s environmental social responsiblity and public image
What types of surge vessels ERGIL manufacture?

An Äager Brand, ERGIL is a global specialist in designing, engineering and manufacturing surge vessels with an extensive experience. ERGIL manufactures two types of surge vessei which are categorized as Bladder type and Compressor type  for the water pipeline, desalination plants, crude oil pipelines and other applications. ERGIL provides surge vessels in horizontal and vertical types are avaliable and orifice plates, butterfly valves, level instruments, pipeline etc. are provided as required.

Bladder Type Surge Vessel

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

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 required elasticity to push the water into the system following a pump trip, 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 correct 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 or Hypalon Rubbers, or expanded to fit the whole vessel. The bladders are complying with a flange at the top as per client’s vessel details.

Features & Specifications:

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
Design code: ASME and others
Capacities are available from 3000lt to 70000lt
Service Pressures Range: up to 25bar

How does the surge occur?

Surge is expected when pumping water; it can occur when the flow rate of pumps at a pumping station is altered, valves opened/closed along the pipeline, or uncontrolled pump-trips due to power cuts. These can lead to extreme pressures fluctuations which, if not controlled, can lead to disastrous consequences including burst pipes, unnecessary water loss, and supply disruptions. Negative pressures are far more prevalent than high pressures, considerably more destructive, as well as contravening Drinking Water compliance on potable water systems. 100% leakage reduction of any pumping main is impossible until potential surge pressures in the pumping main are reviewed.

ERGIL Surge Vessels  are perfection of 35 years of experience. We developed cost-effective surge control system that provides one of the best internally designed bladder pressure control system.  

Surge Vessel Instrumentation

Fig.3. Intstrumentation of Bladder Type Surge Vessel is indicated 

Fig.4. Completed Bladder Type Surge Vessel (Horizontal)


First of all, the hydraulic analysis (pre-charge either compressed air or nitrogen) will give the result of value adjusted to the pre-charge of pressure. Then, the water will go inside the vessel under static conditions and start to compress once the gate valve is opened. Thus, the water will entire the vessel and led further compress the pre-charged gas until a balance between the liquid and the compressed gas is reached.  Right after a pump trip, the pressure in the pressure line will start to reduce and the elastic energy inside the vessel will led the discharge of water from the vessel into the line. This situation prevents risky low pressure along the pipe. In the pipeline, pressure might become too low and the flow will reverse. Then the water will go into the vessel via reduced diameter (drilled non return valve or bypass) if hydraulically required. Before the static state is reached, several oscillations may occur.


Pressure Vessels
Pressure Vessels
Pressure Vessels

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