Whatman™ VACU-GUARD™ 150 Vacuum Protection Filters
By Whatman/Cytiva
VACU-GUARD 150 is an in-line capsule device designed to protect vacuum pumps and minimize harmful pump exhaust fumes. Useful also as a back up between a cold trap and the pump to protect against vapors if the cold trap fails.
The devices contain a choice of chemical trap with the additional feature of a hydrophobic PTFE membrane that retains 99.99% of airborne particles 0.1 µm and aqueous aerosols. Solvent solutions with low surface tension will pass through this filter. Chemical trap options include the following:
Activated carbon, produced from lignite coal and acid washed after steam activation, creates pores of molecular dimensions within the carbon particle and produces a material with extremely high internal porosity and surface area. Activated carbon is a powerful absorbent ideally suited to remove impurities and odors from gases. Mesh size is 12 x 20.
Molecular sieve, a crystalline alkali metal aluminosilicate with a three-dimensional interconnecting network structure of silica and alumina tetrahedral. Widely used for the removal of water from gases and will absorb molecules with a size of less than 4A. Use with organic and alkaline air streams. Mesh size is 8 x 12.
Desiccant. Anhydrous calcium sulfate is prepared from natural gypsum and impregnated with calcium chloride. The desiccant is neutral, stable and chemically inactive toward reagents other than water. Suitable for use with high velocity acidic air streams. It can dry gases flowing at high speed because of its superior absorption of water and does not shrink, expand or disintegrate in use. With the addition of calcium chloride, the desiccant changes from blue to pink as the limit of absorption is reached. Mesh size is 8.