Packing Liquid Silox

Table of Contents


Silox is a synthetic oil belonging to the group of polydimethyl siloxane. It is colourless and clear with a weak odour.


Silox can be used in all RITTER Drum-type Gas Meters. As opposed to water as a Packing Fluid, Silox can be used under 0 °C. It also has a lower evaporation rate in combination with a viscosity similar to water. Because of this, the Packing Liquid level remains stable over a longer period of time. This leads to an improvement in the repeatability of measurement results, and in a reduction in the required frequency of Packing Liquid level monitoring.

The use of Silox is further recommended when the gas should remain dry or when the gas reacts with water.

Not suitable for wet chlorine gas and alkanes (methane, ethane, butane, propane, pentanes).


  • Use under 0 °C (down to -40 °C)
  • Less evaporation than water due to its lower vapour pressure, resulting in greater stability of the Packing Fluid level and in more consistent measurement result
  • The gas remains dry
  • In general, a lower chemical reactivity than water


Chemical designationcyclic polydimethyl siloxane
Viscosity20 °C4 cSt (=mm2/sec)
25 °C4 cSt
Density15 °C0.96 g/ml
25 °C0.95 g/ml
50 °C0.93 g/ml
Vapour pressure20 °C0.16 mbar
50 °C38 mbar
Boiling Point205 °C
Pour point-40 °C
Flash point70 °C
Ignition point450 °C
AppearanceClear, odourless, colourless fluid

Material Safety Data Sheets

V 1.0 / Rev. 2024-05-22 / Subject to alterations.