Pumps and Valves 15047

Originally Published MPMN March 2005

SPOTLIGHT

Pumps and Valves

Check valves

A manufacturer of disposable fluid-control products offers a line of check valves in a variety of styles. In-line back valves feature a preloaded normally closed silicone diaphragm that allows flow in a single direction. Available in different materials, one-way pressure-activated antisiphon valves have a variety of fluid-control applications. Bidirectional luer-activated designs, including needle-free devices, provide consistency in performance and a clear visualization of the fluid path. The devices are made in a Class 100,000 cleanroom using high-speed automation for high-volume output at a low cost. All materials are latex- and DEHP-free and ISO 13485:2003 compliant. NP Medical Inc., Clinton, MA www.npmedical.com

 

Diaphragm pumps

Miniature diaphragm pumps are suitable for applications requiring high-accuracy dosing of low-viscosity liquids. The SMF 2 pumps have a rated fluid flow of up to 52.5 ml/min and a maximum pressure of 1.16 psig. The flow per stroke ranges from 0.10 to 0.25 ml. Measuring 3.35 in. in length and weighing 6.4 oz, the long-lasting pumps offer quiet operation and low power consumption. Flow repeatability of 5% or better is achieved through the use of a microprocessor-based electronic oscillator board with eight preset frequencies. Ac-powered pumps are available for users with their own electronics. In both 12- and 24-V dc versions, an ethylene-propylene diene methylene terpolymer valve and diaphragm materials are standard. The devices are self-priming and run dry safely. Rietschle Thomas, Sheboygan, WI www.rtpumps.com

Pinch valves

A line of dual-acting, pneumatically actuated pinch valves includes both normally opened and closed versions. The devices accept tubing with outer diameters ranging from 0.125 to 1.000 in. Strong pinching forces also allow the valves to accept a variety of flexible tubing up to 70A durometer. The units have no wetted parts and feature snap-in tube loading for quick changeout of disposable tube sets. Splash seals guard against spills, prevent contaminants from entering the valves, and enable them to be cleaned without being disassembled. The valves have a life span of more than a million cycles and generate no heat. Custom designs and value-added assembly services are also provided. Acro Associates Inc., Concord, CA
www.acroassociates.com

Flow-control valves

A company has added two products that combine needle- and check-valve flow controls to its line of valves. The JFC-4 and JFC-5 are used to control airflow from air cylinders. This operation controls the speed at which the piston strokes, either while extending or retracting. The J-Series of products allow free flow from the inlet to the outlet, which passes the needle and check valves. In reverse flow, from the outlet to the inlet, the check valve is sealed. Therefore, the flow goes through the metered passage, which is controlled by the tapered-adjustment needle valve. Clippard Instrument Laboratory Inc., Cincinnati, OH www.clippard.com

Linear diaphragm pumps

Linear diaphragm pumps provide a constant flow of low-pressure air. The Hiblow electromagnetically operated diaphragm pumps achieve airflows starting around 10 L/min and rising to 250 L/min, with pressure up to 0.5 bar. Generating noise levels as low as 28 dBA, they are compact and vibration and maintenance free. The units feature a service life of more than 25,000 hours, making them suitable for applications in pressure therapy devices and therapeutic equipment. Charles Austen Pumps Ltd., Byfleet, Surrey, UK www.charlesausten.com

Metering pumps

A line of high-pressure metering pumps is designed for applications requiring extremely precise, continuous pulse-free fluid flow. The QX series includes four models with a maximum pressure rating of 500, 1500, 6000, and 20,000 psi, respectively. The units can be operated via a computer interface using a front-panel touchscreen display or the firm's PumpWorks software, which runs up to eight pumps. Both methods give users complete control over flow rates, pressure, and other operating parameters. Flow rates range from 0.004 to 500 cm3/min. Made of Hastelloy or stainless steel, the devices feature an optional washout system to minimize corrosion and extend seal life. Vindum Engineering, San Ramon, CA www.vindum.com

Solenoid valves and accessories

A company offers a line of 10- and 15-mm solenoid valves, bodies, and manifolds. The two- and three-way normally open and closed valves feature a variety of voltages, including 12 and 24 V dc, and a low-watt 24 V dc. Flying lead, spade, line, and 90° connectors provide connection versatility. Providing added flexibility, single bases also feature 2.5-mm porting options. Single- to 12-station manifolds are available. Pneumadyne Inc., Plymouth, MN www.pneumadyne.com

Metering pump

A ISO 9001-certified company offers a pump that achieves precision ultralow-volume submicroliter dispensing. The Model SMTRH uses the firm's patented CeramPump valveless-piston pumping principle and has a fluid path of zirconium and ceramic. The device is driven by a precision stepper motor and dispenses between 500 nl and 5 µl. The piston-stroke displacement is adjusted using an easy-grip flow control ring graduated in 450 divisions. The low-dead-volume pump head design ensures maximum bubble clearing, and provides a typical stroke-to-stroke precision of 1% or better. Stepper motor controllers featuring quick-start and intelligent programmable control capabilities are also available. Fluid Metering Inc., Syosset, NY www.fmipump.com

Ball valves

A line of ball valves includes an actuator that provides a systems approach to piping-system design. Complementing the modularity and flexibility of the company's 546 series of valves, the EA 21 electric actuator features integrated emergency manual override and automatic adjustment of voltage and frequency for on-and-off or process control applications. Available with universal voltage adjustment of 100 to 230 V ac or a 24-V ac/dc power module, it achieves 250,000 cycles. Cycle-time adjustment and monitoring, current monitoring, cycle counting, and position feedback for 4- 20-mA inputs are among the offerings. Measuring 3¼8 to 2 in., the valves include Models 131 in polypropylene, 132 in polyvinylidene, and 133 in PVC and CPVC. George Fischer Inc., Tustin, CA www.us.piping.georgefischer.com
 

Single-piston pump

A single-piston pump offers process development versatility for liquid-metering applications. The 2-1 Development Unit achieves flow rates of up to 50 ml/min and is rated for pressures up to 125 psi. Options include an enclosed or tethered control box. The device can be operated with the built-in analog control knob, the users' own analog signals, or ASCII commands via RS-485/232 communications. It works in forward and reverse modes and does not lose prime. Sliding ceramic plates internally seal the pump's liquid path, eliminating the need for valves to control flow. Encynova, Broomfield, CO www.encynova.com

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