The P3100/P3200 deadweight tester user manual refers to ST-55 fluid as "Shell Spindle Oil 22, our reference 55-655." We more commonly refer to it as ST-55 oil. Historically it has also been called Tellus 22, Morlina S2 or EL 22 or Fluid 22.
ST-55 is almost always used with liquid deadweight testers, especially current models. Density is 879 kg/m3. Viscosity is 55 cSt at 20C, 22 cSt at 40C. Surface tension is 0.0283 N/m @20C.st
Part Number: 3905893
Description: ST-55 Operating Fluid (Oil), Quart
Price: Send by email
Notes: 1 quart is equal to 0.95 liter. The reservoir of a P3100 deadweight tester has a usable volume of about 400 cubic centimeters (25 cubic inches), or about 0.4 liters or 13.5 US fluid ounces or 0.4 US quart.
MSDS sheet is here,
EL DWT Fluid-22 (ST-55, 55-655, PA9152, DW6293)
Sample certificate of analysis link is below that shows shelf life of 4-years.
Fill date and lot number are shown on label.
Official information, quotations and terms and conditions can be obtained from our Orders group at 1.877.355.3225 or orders@flukecal.com
Purchase order may be faxed to 1.425.446.5716 or emailed to orders@flukecal.com
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