PRODUCTS & SERVICES
Spotlight on Pumps and Valves
Metering pumps
Miniature metering pumps are suited for precise, fixed-displacement, low-pressure OEM applications. Requiring only 2 3/8 in. of panel space, the pumps feature displacement ranges of 0–50 and 0–100 µl/stroke. The moulded components are fitted with a matched ceramic piston and liner housed in a fluorocarbon cylinder to enhance chemical resistance. Fluid Metering Inc., Syosset, NY, USA.
Needle valves
Subminiature precision needle valves are designed to enable precise, sensitive, and repeatable flow control in pneumatic and fluid systems. The NV-30 series valves feature a needle with a 7- to 8-turn flow-control adjustment and maximum flow that is approximately equal to a 0.025-in. orifice. Constructed of nickel-plated brass, the corrosion-resistant components come with 1/16- or 1/8-in. barbed fittings. Designed for precision gas metering and circuit speed or sequencing control, the valves are suited for use in medical instrumentation, laboratory analysis equipment, and gas analyzers. Airtrol Components Inc., New Berlin, WI, USA.
Pinch valves
Pinch valves with a brightly coloured on-off rocker switch are suited for use with soft-wall flexible tubing. The valves can pinch closed tubing at pressures from 0 to 60 psi for extended periods of time; models with higher or lower pinching forces are available. The valves can be supplied with an adjustable flow control needle. Both the On/Off Rocker and On/Off Flow Control models are available for 2.4 to 9.6-mm-OD tubing. Z-Man Corp., Grand Rapids, MI, USA.
Diaphragm valve
Limit stops are desirable on diaphragm valves to prevent overclosure and to increase diaphragm life. Designed as an alternative to valves with a rising-spindle design, a company has developed a rising handwheel and bonnet assembly in which the limit stop is completely enclosed. This prevents the setting from being changed once it has been adjusted to the desired position. The bonnet accommodates rubber screw-type and PTFE bayonet diaphragms. The assembly is constructed from stainless steel CF8. Anderson GmbH & Co. KG, Dortmund, Germany.
Ceramic components
Because of the tight manufacturing tolerances that can be achieved, ceramic metering valves and pumps are suited for precise flow measurement in blood analysis equipment, dialysis machines, and related medical devices. Ceramic-based components exhibit greater resistance to wear and corrosion than parts made from stainless steel, titanium, and other alloys, according to the company. Only USP Class VI materials are used in the fabrication of parts intended for use in medical devices. Coors Ceramics Co., Golden, CO, USA.
Standard and custom valves
More than 35 standard valves are available in a variety of configurations for fluid-transfer applications. The range of products, many with proprietary design elements, includes normally closed, dual, and low-pressure check valves. In-line, antisiphon, and aspiration models are also offered. The company can supply custom designs with alternate connections and pressure ratings.
B. Braun Medical, Melsungen, Germany.
Piston pump
A rocking piston pump produces up to 8 bar pressure and 75 L/min of free air displacement. The oil-free pump is suited for use in the device industry and other sectors in which a continuous supply of clean air is required and oil-mist contamination is undesirable. A forced-air cooling system built into the pump redirects crankcase pressure to cooling ports in the cast alloy head. Charles Austen Pumps Ltd., Byfleet, Surrey, UK.
Safety valve
Designed to protect vacuum systems in the event of a power outage, a safety valve isolates the vacuum system and vents the mechanical pump. The Vacuum Sentry can prevent time-consuming and costly cleanup of vacuum lines that have been compromised by oil streaming back from the pump. A small orifice in the valve vents the mechanical pump and restores atmospheric pressure to enable trouble-free restarting once the power returns. MKS Instruments S.A., Le Bourget, France.
Check valve
By minimizing the number of connections required during fluid transfer operations, a three-way check valve reduces the risk of contamination. Fluid aspiration and injection can be performed without adjusting the valve or removing the syringe. Suited for use with infusion pumps and syringes to administer liquids, the check valve resists stress cracking and is compatible with adhesives and welding processes. The material meets USP Class VI criteria, and the company's quality systems are certified to EN 46001. Filtertek S.A., Plailly, France.
Rotary vane pump
Rotary vane pumps are traditionally used for evacuating, transporting, and compressing air or other gasses. A company has succeeded in adapting this technology to the conveyance of liquids, enabling practically pulse-free pumping of a variety of fluid media. The compact, low-noise pump has a maximum capacity of 2 L at pressures up to 2 bar. All hydraulic parameters including viscosity, speed, and pump gap are adjustable. ASF Thomas Industries GmbH, Puchheim, Germany.
