Processing Magazine

Plastic ‘quick-connects’ expand lab- and industrial-equipment options

Plastic tube-fittings top metal quick-connects, author says, based on ergonomics, light weight and affordability

January 8, 2014

by Riley Phipps, Value Plastics, Inc., a Nordson Co.

Value PlasticsBased on 60 years of design evolution, and meeting stringent requirements for medical-device use, today’s plastic-tube connectors give equipment- and device-makers and users, lightweight, cost-efficient and reliable options for mission-critical applications.

In industry, and with lab and in-plant test and calibration instrumentation, plastic-tube connectors convey substances that flow, including liquids and gases, slurries, powders and masses of small solids. No longer just for medical equipment, plastic connectors are increasingly integrated into lab instruments and industrial equipment.

The food & beverage, pharma, oil and gas, alternative fuels, printing and semiconductor industries –– in production, packaging and material handling –– have embraced plastic-tube connectors as viable for liquid-filling equipment, fuel supplies, and low-pressure pneumatic and hydraulic systems.

Plastic connectors are light weight, and have chemical resistance and non-corrosive properties well-suited for industrial and lab equipment. Composites use makes them flexible in terms of configuration and ease of making connections. Cost is lower compared to metal connectors for quick and easy tubing connections for servicing equipment, changing consumables and equipment portability.

Choosing the type

Choosing a connection type depends on the expected frequency of connection/disconnection, servicing and safety needs, and user expertise.

When frequent maintenance and servicing is required, quick connects are preferred over general threaded fittings for fluid control, improving user-interface performance. They incorporate features that prevent spillage and minimize the potential of accidental misconnections or leakage.

Quick connects minimize service-related downtime via quick and easy access to fluid lines. Built-in shut-off valves can automatically close the line to stop fluid flow and prevent leakage during disconnect. Conversely, quick-connects can be equipped with open-flow valves that allow a consistent flow, with little flow-path impedance, to minimize media disturbance and maximize flow rates.

Many metal and plastic quick-connects, however, lack good ergonomics. It can be difficult to intuitively understand how one works and they can prove difficult to manipulate. Just making a basic disconnection can sometimes be a significant challenge, leading to safety risks and fumbling inefficiencies. These drawbacks have inhibited quick-connect usage and reduce their effectiveness.

A better way to go

The latest advances in plastic quick-connects deliver a significantly improved level of human-interface engineering, including ease of use and intuitive operation, compared to conventional metal and plastic quick-connects. These devices are equipped with simple thumb-latch and side-latch mechanisms, for one-hand connection and disconnection and easy handling in lab and industrial fluid management.

Dual-latch quick-connect interface – A versatile plastic quick-connect solution incorporates an intuitive dual-latch push-to-connect design, with large, ergonomic buttons that deliver an audible click on connection. Grips are for easy handling, even with gloves.

Incorporating such a design, the one series of quick connects includes 10 different color options, allowing for useful color-coding verification techniques. These male and female connectors are made from nylon and buna-N materials, which are autoclavable, ethylene oxide (EtO) compatible and gamma-radiation stable, and capable of a working pressure up to 30 psi. They also provide excellent chemical resistance and are great for higher temperature applications.

The new dual-latch-design quick-connect maximizes ease of handling and prevents misconnections.

Thumb-latch quick-connect interface – Features ergonomic grips and automatic shut-off valves for better connecting and disconnecting ease and optimum fluid control. One new design universally interchanges with other thumb-latch plastic connectors, and may be used with PVC, polyurethane, silicone and other types of flexible tubing.

These new thumb-latch quick-connects, produced in acetal and polypropylene for a variety of application uses, have single barbs capable of increased pull-off resistance when compared to multi-barb styles. With a secure seal and superior tubing retention, the prospect of leaks and accidental disconnection is minimized. In short, operator ease-of-use is enhanced, and the range of available options for laboratory and industrial equipment increased.

Side-latch quick-connect interface – Significantly improving on quick-connect intuitive-use, plastic side-latch designs work almost instinctively. One instance, available in nylon and for use in small-bore applications in many fluid delivery areas, is intuitively so from the minute it is picked up.

Audible clicks on connection, ergonomic shape and design simplicity – all reduce the likelihood of human error.

Quarter-turn lug-style interface – A popular connector in instrumentation applications, the mechanism produces an audible click and visible indication when the pair is fully connected. Interlocking teeth provide an inherently rugged connection, and the rotating collar allows for independent rotation to prevent tube twisting and kinking.
These connectors offer significant ease-of-use advantages over present commercially available lug-style connectors. Its ergonomic ten-point grip on both halves of the connector, and additional gripping area, allow for easier opening and closing of the connector, while two wings have been added to the male side to further facilitate connector operation. This connector offers a feature-rich quick-connect.

Final words

Although plastic quick-connects may not be applicable for all plant and laboratory uses — for high pressure pneumatics and hydraulics metal is generally required, for example, — their light weight, design flexibility and ergonomics makes them viable candidates for liquid-transfer and filling processes, operating and integrating portable instrumentation, and where fluid connections between flexible equipment are required. Cost considerations sometimes curtail use of metal quick connects. Plastic quick-connects, however, present a price-point significantly less than metal connectors.

These factors increasingly position plastic quick-connects as an attractive option for many critical applications in laboratory and industrial environments.

About Value Plastics, Inc., a Nordson Co.
Value Plastics manufactures and markets an innovative line of fluid-management components for flexible tubing. Products include quick-connect fittings, luer fittings, check valves and tube-to-tube and threaded fittings. Value Plastics products find global application in demanding research and specialty industrial applications.
About Nordson Corp.  
Nordson Corp. delivers precision technology solutions that increase throughput, productivity and up-time, enable new products and features, and decrease material usage. The company engineers, manufactures and markets products and systems used for dispensing adhesives, coatings, sealants, biomaterials and other materials, fluid management, testing and inspection, and UV curing and surface plasma treatment, all supported by application expertise and direct global sales and service. Nordson serves a wide variety of consumer non-durable, durable and technology end markets including packaging, nonwovens, electronics, medical, appliances, energy, transportation, building and construction, and general product assembly and finishing. Founded in 1954 and headquartered in Westlake, Ohio, the company has operations and support offices in more than 30 countries.
For more information, contact George Porter, VP of business development for Value Plastics; 3325 South Timberline Rd., Fort Collins, Colo. 80525; Phone 970-267-5200; email;