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Standards for cryogenic valves
Do you know where I can get some documents of testing specification or US standards for cryogenic valves (DN 250)? Or could you give me some suggestion for that?
Recent material and fabrication developments in low-temperature regeneration
In the area of low-temperature regeneration, what are some recent material and fabrication developments?
Vendors for cryopreserved rat arteries
My department is starting up a microsurgery training lab as an adjunct to our resident curriculum. Instead of using live rats, we want to pursue the option of using cryopreserved rat arteries. I have been unsuccessful in finding animal/rodent vendors who deal in this. I basically found a lot of...
Source for pressure switch
Where can I find a pressure switch operating in the range 0.2 to 0.4 psi which is not affected by magnetic fields up to about 1000 Gauss?
Cryostat for storing fish samples at -20 degrees C
We are a small Food Chemistry Laboratory functioning within the Seychelles Bureau of Standards. We wish to purchase a cryostat for the purpose of storing fish samples at *-20ºC* prior to the analysis of Histamine in the tissue of Tuna by HPLC.
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Mixed Refrigerant Cycles
Most cryogenic refrigeration systems, both large scale systems and cryocoolers, use helium as a working fluid. There are a number of advantages to helium, not the least of which is that helium remains a fluid down to the lowest achievable temperatures. In order to freeze helium, pressures of over 20...
Fountain Pumps and He II Phase Separators
Helium II (He II), the second liquid phase of the 4He isotope described in this column in Cold Facts Spring 2010 (http://2csa.us/he2), can be modeled as consisting of two interpenetrating fluids. One, the superfluid component, has zero viscosity and entropy and the other, the normal fluid component, has nonzero viscosity...
Turboexpanders
A vital technology in the refrigerators and liquefiers described in Cold Facts Volume 31 Number 3 is that of turboexpanders. These devices are rotating machines in which the process fluid (e.g., helium) does work against the turboexpander while moving from high pressure to a lower pressure and thus is cooled....
Food Processing
Cryogenics and Food The industrial gas industry provides a host of products and services related to food. The various gases have useful and sometimes fascinating applications in food industry. “The food industry is not a homogenous industry. The needs of customers processing hamburger vs. poultry vs. strawberries vs. seafood, for...
Primary Standards
Elie K. Track Hypres, Inc. elie@hypres.com http://www.hypres.com/ Primary standards involve the exact definition and realization of units of measurement for various quantities, time, length, mass, voltage, resistance, current, etc. International agreements based on the latest scientific knowledge define those units, and their realizations vary depending on the unit itself. For...
Shrink Fitting
Robin A. Rhodes Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Shrink fitting, (or “compression fitting” as it is sometimes called), is a method used to insert a pin or bushing into a housing or other assembly requiring an extremely tight tolerance fit. It can be used as an alternative to...
Telecommunications
From the Winter 2004 issue of Cold Facts magazine The recent M-Calc IV — 4th Industry Assessment workshop discussing military and commercial applications for low-cost cryocoolers, held in November in San Diego, highlighted progress being made in cryogenics as applied in telecommunications. The reliability and long lifetime of projects now...
An Issue of Pressure and Flow Rate in a Supply Tank
Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow...
Using MLI on VJ Line Joints or Cryo Storage Tanks
When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help...
Separated layers of ice over a pipe
I want to know that why there are different layers of ice over a pipe carrying a cryogenic fluid, each layer separated with clear marks / lines? What do these layers signify?