VERYCLEAN VAPOR DEGRASER (VD) MANUFACTURES   various types of VDs FOR solvents  used in VDs. There are two types of VDs. One is a vapor immersion unit which usually has two solvent-filled sumps (the boil sump and the cold sump which is filled with clean, distilled condensate solvent and is often used for rinsing). An ultrasonics-equipped degreaser is a version of a vapor immersion type degreaser. The other type of degreaser is a vapor/spray unit in which the solvent is boiled in the very bottom of a one-sump degreaser. There is a perforated metal stand just above the boiling solvent. A metal basket filled with dirty parts is usually placed on this stand. The basket or parts are not immersed in solvent. Instead the vapor made by the boiling solvent encompasses the parts completely and removes the oils and soils. The oils and soils, now diluted into the condensing liquid, will drip back into the boiling solvent below. There is a manual spray wand, which is sprayed under the cooling coils, directly on hard-to-remove soil.

Near the top of the either type of degreaser is a set of cooling coils, that catches the vapor before it escapes from the unit. It cools and condenses it back to its liquid form and flows it back to a clean condensate tank and finally it goes back to the boil sump or the rinse tank. Since oil and grease boil at a higher temperature than for chlorinated solvents, the vapor caused by the now oil mixed solvent, only vaporizes the clean chlorinated solvent not the dirty oil, if the temperature settings are correctly set. Therefore only clean vapor is used to clean parts.

There are 3 standard chlorinated degreaser type solvents – trichloroethylene(TCE), methylene chloride and perchloroethylene (perc). There are other new VD solvents which are more expensive but have certain characteristics which require their use in some cleaning situations. By the way, chlorinated solvents (and the newer vapor degreaser solvents) have no flash point so they are not flammable. Non vapor degreasing solvents like acetone, xylene, methyl ethyl ketone, alcohols, etc. should not be used in heated tanks that are not explosion proof like VDs. All are flammable.