BOC Edwards is launching a new range of single-stage and two-stage liquid ring vacuum pumps for the evacuation of wet and dry gases. The single-stage pumps offer pumping speeds up to 11,000m3/h for an ultimate vacuum down to 40mbar absolute. The two-stage equipment, which offers greater efficiency at low-end pressures, has pumping speeds up to 5,000m3/h and an ultimate vacuum capability of 33mbar absolute. Liquid ring is a proven, reliable vacuum pump technology, suitable for continuous operation from atmosphere down to 33mbar absolute. It offers the capability to handle condensable vapours and even slugs of liquid entrained in the incoming gas stream, without risk of damage. This makes it a good choice for applications such as vacuum distillation, filtration and drying, where it can be used to scrub wet gas streams. The pumps are available in a choice of materials including cast iron and stainless steel as standard. Specials such as Hastelloy, titanium, duplex stainless steel and aluminium bronze are also available. Liquid ring pumps can use a wide range seal liquids including ethylene glycol, water, sodium hydroxide, toluene, benzene, isopropyl alcohol, enabling chemical compatibility with most processes.