With pumping speeds from 170 to 900 L/min, a line of oil-free pumps for vacuum ovens and dryers contain pistons that are suitable for roughings and backing of turbo, cryo, and ion pumps. The piston-type pumps provide pressure of over 20 mTorr; do not need oil, diaphragms, or cooling water; and do not need maintenance for the first 20,000 hours. An optional soft-start speed control automatically slows the pumps when gas loads are small and increases speed if the pressure starts to rise. Vacuum Research Corp., 2419 Smallman St., Pittsburgh, PA 15222.
Dry vacuum pumps
High-flow dry vacuum pumps are available in pumping speeds of 3.1 and 7.1 cu ft/min and offer a vacuum level of up to 60 Torr, making them suitable for aspirating sticky and viscous substances. Two models are available, with the largest weighing 22.5 lb and having a footprint of
Manufactured with a snap-and-clasp press-on head, a miniature diaphragm pump is suitable for use in gas analyzer, air monitoring systems, blood pressure monitoring devices, nebulizers, and anesthesia equipment. The measurements of the 3013 pump are
Diaphragm air pump
A single-head diaphragm air pump provides free flows to 35 L/min, pressures to 22 psi, and vacuums to 21 in.Hg. The T2-01 pump operates with a high-efficiency dynamic valve design that uses 20% less power than other units in its performance range, according to the manufacturer. The pump, which has no exposed moving parts, is suitable for use in portable air and gas applications. Multihead configurations that provide up to 120 L/min free flow and vacuums to 25 Torr are also available. T-Squared Manufacturing Corp., 1275 Bloomfield Ave., Unit 3-50A, Fairfield, NJ 07004.
Designed to be completely maintenance free, a line of pumps can be located wherever fluidic requirements dictate, regardless of maintenance accessibility. The pumps offer space and weight savings and up to 10 times the life cycle of conventional syringe pumps, according to the manufacturer. LPV-series pumps are available in custom and 50-, 250-, 750-µl configurations. The coefficient of variation is 0.04% at full stroke. The Lee Co., 2 Pettipaug Rd., Westbrook, CT 06498-0424.
Oil-free vacuum pump
Combining a structured, molded diaphragm; high-speed check valves; and a brushless dc motor, an oil-free vacuum pump eliminates EMI/RFI present in brush-type motors. The N813AN pump provides a 13 L/min flow rate with an end vacuum of less than 0.5 mbar. The low vacuum range makes the two-stage, dry diaphragm pump suitable for use in portable medical and roughing applications. Chemical-resistant versions and versions with different flow rates are also available. KNF Neuberger Inc., 2 Black Forest Rd., Trenton, NJ 08691-1810.
A multichannel dispensing system uses a single motor drive to control multiple fluid channels. The Multiplex dispensing system is digitally programmable for dispense rate and volume and delivers a pulse-free linear profile with 40,000:1 resolution. The self-priming ceramic piston/cylinder pump modules use industry-standard fluid fittings and are interchangeable. Applications include diagnostic reagent striping, microtiter plate dispensing, form-fill-seal applications, and sterile bottle, vial, and syringe filling. IVEK Corp., Fairbanks Rd., North Springfield, VT 05150.
Offering up to 32 channels on a single drive, a pump provides near pulseless flows at rates from 0.6 to 28 ml/min. The PumpPro MPL pump features an updated pump head that allows for greater flow rate control and improved tube life, according to the manufacturer. Additionally, a 30-turn occlusion knob allows for fine adjustment of flow rate on each channel and can be locked to maintain the setting and prevent accidental tampering. The occlusion adjustment is separated from the tube-loading lever and remains constant when tubes are changed. Watson-Marlow Inc., 220 Ballardvale St., Wilmington, MA 01887.
Specifically designed to handle highly corrosive liquids, a high-purity Teflon metering pump can handle liquids as hot as 250°F. The Model SV104, a self-contained unit, has a solid-state speed controller that provides variable flow adjustment from 100 to 800 ml. The pump is self-priming, maintains a constant flow within 2% under stable voltage and pressure, and has a maximum outlet pressure of 15 psi at a flow rate of 100 ml/min. Valcor Scientific, 2 Lawrence Rd., Springfield, NJ 07081.
A sealless, magnetic-coupled, corrosion-resistant centrifugal pump is designed for applications requiring both low flow and the development of pressure. The Model 320 can handle a flow of up to 3.3 gpm with pressures of up to 17.3 psi. The pump has the durability of a centrifugal pump, making it suitable for continuous duty, according to the manufacturer. March Manufacturing Company, Inc., 1819 Pickwick Ave., Glenview, IL 60025.
Miniature self-priming 5-µl micropumps are designed to handle programmed, precision-controlled microdispensing of high-purity or aggressive fluids. The pumps can be factory set to handle discrete fixed output flows at volumes of 3 to 8 µl per solenoid actuation. It provides an inert fluid path for precise, repeatable dispensing with an accuracy of 0.5 µl. The pump can also provide a continuous pulsating flow to replace maintenance-intensive peristaltic pumps. Bio-Chem Valve Inc., 85 Fulton St., Boonton, NJ 07005.
Offering two pump heads that can by used in both series or parallel, 5-in.-long lightweight pumps can produce up to 20 L/min at free flow. The Dual Head C Micro Air pumps can attain a maximum pressure of 28 psi and a vacuum rate of 26 in.Hg in series performance. The pumps can attain a maximum pressure of 13 psi and a vacuum rate of 23 in.Hg in parallel performance. Sensidyne Inc., 16333 Bay Vista Dr., Clearwater, FL 33760.
Miniature diaphragm pumps
An oilless miniature diaphragm pump series provides pressures of up to 7.1 psi with open airflow of 1.18 L/min. The 3D-series pumps have a chemical-resistant valve, diaphragm, and head assembly and will mount on any plane. Stroke options are available for performance modification; dc voltage options are available in iron or ironless core motors. Suitable applications include air samplers, gas detection systems, blood pressure and respirator monitors, and portable aspirators. Gast Manufacturing Inc., P.O. Box 97, Benton Harbor, MI 49023-0097.