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Hydropneumatic Control System

Finding a Fluid Control Solution

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Fluid Transport System Issues

The first step in finding a fluid control solution is understanding the problem.

Air-Over-Water or Bladder Type

Determine which control system is best-suited for your protection.

PULSCO will recommend which type of system is best for your specific application and project. In direct contrast, some manufacturers recommend only bladder systems or only Air-Over-Water systems, often citing misinformation as fact.

Material Selection

PULSCO has assisted with Hydropneumatic Control System material selection since 1922. We select materials based on code and regulatory requirements that assure optimum performance. Each material has been selected for specific applications and environments.

Cost of Ownership

PULSCO designs our Hydropneumatic Control Systems to protect capital equipment, save system manpower, and save money longterm.

Surge and Pressure Control Systems

Often times users are unsure of the problems inherent in their fluid transport systems.

Bladder and Air-Over-Water Control Systems solve an array of fluid transmission and delivery challenges. Water Hammer, also referred to as surge or shock, is a pressure transient event that is caused by sudden changes in flow conditions. These damaging shock waves and pressure transients are often due to pump start up, sudden pump shut down or valve closures.

PULSCO works with its customers to determine the best system to meet their needs. We account for dependability, safety, and cost efficiency for our surge suppression and pressure control systems.

Eliminate Water Hammer

Protect Pipeline from Failure

Maintain System Control

Protect Pump and Valve from Damage

Minimize Pump Cycling

Reduce Pump Wear and Premature Failure

Air-Over-Water Surge Control Systems
Bladder Surge Control Systems
Air-Over-Water Pressure Control Systems
Bladder Pressure Systems
Nimbus Air Compressor for Air-Over-Water Surge/Pressure Systems
Aeolus Air Control Center - Air Compressor for Air-Over-Water Surge and Pressure Systems
Skypark Series Controller for Surge and Pressure Control Systems
Bladder Monitoring Device for Bladder Surge/Pressure Systems
ShockTracker for Hydropneumatic Control Systems

Issues with Fluid Transport Systems

Pressure surges and water hammer are the biggest problem in water transmission, water distribution and sewage force main systems. Surge Control Systems are designed to eliminate water hammer that results from pump start up, sudden pump shut down or valve closures.

Surge Control Systems

Surge Control Systems include an ASME steel tank filled with water and compressed air connected to a water trunk line through a nozzle containing an energy dissipater.

The Surge Control System resists water entering the tank, but allows exiting water to easily flow out. This reduces the shock pressure wave to a manageable level.

A shock absorber and water accumulator eliminates or reduces water hammer.

Surge Analysis

PULSCO’s Surge Analysts are experienced in modeling systems for a large variety of fluids and pipelines, including all pumps and valves for transmission and distribution. Proposed solutions take into account short term and long term plans by owners and planned operation.


Water/Wastewater Systems
Booster Pump Stations
Sewage Force Mains
Hydrocarbons Distribution

Issues with Fluid Transport Systems

PULSCO’s Hydropneumatic Pressure Control Systems are designed to provide a volume of fluid to a system within a specified pressure range. These systems are often used to provide a continuous source of pressure to treatment plants, annular monitoring systems, rural neighborhoods, and other distribution lines.

The system is used to minimize pump cycling and provide high pressure water for various applications. It performs as a pressurized accumulator delivering product on demand.

Pressure Control Systems

PULSCO’s Hydropneumatic Pressure Control System will increase the life of the system and save the cost of electro-energy to drive the large pumps.

The equipment that maintains system water pressure within a defined operating range by starting and stopping pressurization pumps and adding/venting air from a tank system to keep up with the demand.

Continual pump cycling increases the risk of pump failure and unscheduled downtime for maintenance service. PULSCO pressure systems reduce pump wear and premature failure.

Pressure Analysis

Pressure systems increase pump life by reducing pump cycle times and act as an alternative to significantly larger elevated storage tanks.

With the PULSCO Pressure Control System installed, the pumps work to refill the pressure tank. The pressure tank provides the fluid and pressure to the system. When the tank’s fluid volume reaches a low set point, the pressure control panel calls for the pump to turn on. When the tank is refilled, the pressure control panel triggers the pump to turn off.

Given a desired pump cycle time, maximum demand of the system, and specified pressure range, PULSCO can size and design a complete pressure control system.


Water Treatment Plants
Rural Community Water Supplies
Fire Suppression, Mining Equipment
Industrial Applications
Hydrocarbons/Fuel Farms/Off-Shore

Can be designed for any volume

Air-Over-Water systems can be designed for any volume, where the tank size limited only by shipping restrictions and site limitations. The air compressor provides a local source of compressed air to recharge the tank when needed. The system is controlled automatically using a controller and other system components.

Monitoring equipment recommended

Air-Over-Water systems appurtenances and controls automatically adjust the level to keep it in the intended range, making the system more resistant to the effect of small leaks in valves, or joint connections.

Routine Maintenance

The air compressor and instrumentation needs to be maintained in good condition, and the solenoid valves should be activated periodically. Typical maintenance on the Air-Over-Water equipment can be performed without isolating the tank.

Better suited for smaller spaces

Bladder systems are recommended for smaller tank volumes or at sites that have limited access to power or onsite maintenance personnel. A flexible bladder membrane maintains the separation of gas and fluid, preventing gas from being absorbed into the fluid.

Monitoring equipment recommended

While not necessarily required, it is recommended that monitoring instrumentation be installed to improve maintenance and assist in troubleshooting. It is important to confirm adequate volume of air is in the tank to protect the system.

Routine Maintenance

Bladder systems have fewer components to install and maintain. Once the system has been confirmed to be running properly, minimal human interaction is required for operation. Tanks must be isolated during bladder changes.

Tank Material Selection

Carbon Steel

Stainless Steel

Bladder Material Selection


Flexible Vinyl (PVC)

Applications | Water & Potable Water

Any Size Bladder


Flexible Vinyl (PVC)

Applications | Water, Sewage & Ammonia

Any Size Bladder



Applications | Water, Sewage, Petroleum & Liquid Propane Gas

Any Size Bladder



Applications | Water, Potable Water, Sewage, Petroleum & Liquid Propane Gas

Any Size Bladder


PP/EPDM Based Thermoplastic

Applications | Water, Sewage, Petroleum, Liquid Propane Gas & Ammonia

Bladder Size | Less than 6,000 Gallons



Applications | Water, Potable Water & Sewage

Bladder Size | Less than 500 Gallons

Cost of Ownership

The cost of a system is dependent upon the size and pressure rating of the tank, the operating pressure of the system, and the instrumentation and controls. As a general rule, cost of ownership favors Bladder Systems for volumes up to 2,000 gallons, and favor Air-Over-Water systems for volumes greater than 6,000 gallons.

Direct Costs


Indirect Savings

The benefits from having an optimally designed system are considered indirect savings.

Failure Prevention
Reduced System Downtime
Reduced System Maintenance

Cost of Ownership Graph - Air-Over-Water vs Bladder Hydro System

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