When you order a McDaniel fillable gauge you may choose to fill it yourself or you may order it factory-filled with the liquid of your choice. Thus you can maximize inventory utility and minimize inventory cost.

   Glycerin filling  has a lower operating temperature limit of 32ºF (0ºC)
undiluted.  The mixture of distilled water in proportions up to 35% will lower the limit commensurately, to -40ºF (-40ºC).

   Silicon can extend the lower temperature limit to -60ºF(-50ºC).

   The maximum temperature limit is not determined by the fluid but by the gauge's synthetic case seal.  At elevated temperatures the seal may bake and lose elasticity.

Warning: Glycerin filled gauges should not be used in applications involving strong oxidizing agents such as chlorine, nitric acid or hydrogen peroxide. (Refer to ASME B40.1)