Pumps & Reservoirs

Introduction to Pumps and Reservoirs

A closed loop liquid cooling system utilizes a pump to circulate the coolant to the heat load and back to the cooling unit.

Various types of pumps are used in ELECTRO IMPULSE LAB,. INC. cooling units, depending on the coolant and the flow, pressure and temperature requirements of the application. Our cooling units generally use vane, gear, turbine or centrifugal pumps, whichever is best suited for the application. These pumps are designed for continuous duty at maximum rated pressure and, where necessary, are fitted with a bypass pressure relief valve to protect the pump and system from excessive pressures. Some coolants and applications require the use of special pumps such as wet motor designs, sealless magnetic drive pumps and pumps designed for extreme temperature ranges. Many types of pumps are available, including those designed for 50Hz, 400Hz, or for DC line voltages.

Higher pressure pumps may be required in some cases. This often depends on the characteristics of the piping between the recirculating cooler as well as the customer's equipment to be cooled. There are several factors which can lead to a large pressure drop (and hence the need for a higher pressure pump). Some of these factors include:

  • The recirculating fluid viscosity is greater than 20 centistokes.

  • The external interconnecting piping is improperly sized for the required flow rate.

  • There is a long length of interconnecting piping (i.e. a long distance between the cooling unit and the equipment to be cooled).

  • Other restrictions to fluid flow within the equipment to be cooled.

  • The equipment to be cooled is on a higher elevation than the cooler.

The inlet (or suction) of the pump is typically connected directly to a stainless steel reservoir with the following characteristics:

  • Full flow-through design.

  • Sealed from ambient air and protected from over pressure.

  • Allows for filling of the coolant.

  • Allows for purging of entrained air/gasses from the coolant.

  • Provides for a positive suction head to the pump inlet.

  • Allows for expansion of the coolant. Some of our special units may employ accumulators or other equipment, in addition to, or in place of the reservoir.

  • Has pressurizeable nitrogen blanket options.

Special Options

Instrumentation and Interlocks

Most ELECTRO IMPULSE LAB,. INC. cooling systems are supplied standard with a coolant supply pressure gauge, coolant supply temperature gauge, reservoir level gauge, over-temperature and low flow switches and front panel fault indication. There are many other optional choices available depending on customer requirements, such as:

  • Flow Meters

  • Resistivity/Conductivity Instruments

  • Computer Interfaces

  • Digital Displays

  • Reservoir Level Switches

Environmental Concerns

ELECTRO IMPULSE LAB,. INC. is concerned about using only environmentally friendly refrigerants in all new designs. We can also support older equipment. We employ licensed refrigeration technicians and refrigerant recovery equipment. We are pioneers in the use of environmentally friendly refrigerants and coolants.

Temperature Controls

Our refrigerated units feature a high accuracy solid state temperature control system. The refrigeration system uses hot gas bypass circuitry for excellent temperature control over varying heat loads.


We can provide active deionization equipment that will condition and maintain water solutions for high resistivity applications.

Filters and Strainers

We are specialists in filtration of flowing liquids. Coolants can pick up and carry particles of dirt, corrosion and other system impurities, which can not only damage the cooling system, but can also foul the user's equipment. Depending on requirements, filters and strainers can be provided. They can be fitted with filter differential gauges, switches, indicators and bypass loops, enabling the filter to be changed while the cooling unit continues to operate.

Outdoor/Weatherproof Units

Our optional outdoor and special application units are designed with all the necessary components, hardware and cabinetry to supply highly reliable systems capable of withstanding years of use in the extreme/special environments for which they are designed. We can provide systems for any application, including outdoor installations, harsh environments, or shipboard and airborne applications. Please contact us with your requirements, as we will be pleased to quote on special or unique requirements.

Multi-Path Outlet

We can provide units with multiple path outlets so that one cooling unit can cool multiple heat loads. The cooling system may be fitted with distribution manifolds, additional pumps and instrumentation and interlocks for each path as required by the customer.

Microprocessor Compatibility

The cooling unit operation is directed by a proven control system that can be integrated with microprocessor monitoring and control systems. Flow rate, refrigeration system operation and coolant temperature are precisely controlled to maintain cooling to specified limits.

Miscellaneous Options

  • Heater Packages

  • Auto Reservoir Fill

  • Extended Temp Range

  • Discrete Interlocks

  • Remote Controls

  • Seawater Compatible

  • High Ambient Temp Pkg.