Cryogenic  Pumps 

Cryogenic pumps are designed to move coolants and cryogenic liquids. They are built to withstand and operate in extremely cold temperatures. Cryogenic pumps feature hermetically sealed designs to minimize heat leakage from the motor or contamination by process fluids into the cryogenic fluid. Long shaft cryogenic pumps are designed with the pump motor and mounting flange separated from the pump impeller by a long shaft. The pump impeller is submerged in the cryogen or freezing liquid. This minimizes the leaking of heat from the motor into the frozen or freezing cryogenic fluid. Long shaft cryogenic pumps may be welded or bolted to a variety of cryogenic equipment, including dewars and cryostats.

A dewar is a specially insulated container designed to store liquefied gases, such as the liquid nitrogen used as a coolant in cryogenic applications. A cryostat is a device used to maintain the temperature of the coolant. A centrifugal pump is typically used to transfer cryogenic liquids between a storage tank or tanker car because of their ability to produce and maintain a high flow rate. Cryogenic pumps may also be submersible. A submersible cryogenic pump is frequently used in applications where heat leak is not the most important factor. Submersible cryogenic pumps are used as pumps in vehicles that use liquefied natural gas or in the liquid hydrogen propellant system in a rocket.

Cryogenic pumps for use in extremely cold environments are usually constructed with a vacuum housing to provide a barrier between the motor and the cryogenic fluid. Cryogenic pumps are used to circulate coolant in a variety of applications, including cooling high temperature superconducting cables or magnets, for cooling synchrotron beamline crystals, and as pumps in prototype slush hydrogen applications.