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9 www.nordsonefd.com Should You Replace Your Current Dispense Valve System? In the middle of coping with day-to-day production challenges, it can be difficult to calculate just how much poor valve performance is really c…

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8. Are You Cutting Corners on Your Dispense Tips?

9. Is Your Current Valve Setup Trapping Air?

Entrapped air can cause oozing and variations in shot size. Be sure to purge all air

and fluid lines whenever setting up a system, refilling the fluid tank, or performing

maintenance.Otherrecommendationsinclude:

 • Keepingairlinesshorterthan5feettoreducetheriskoftrappedairand

improve valve response time.

 • Tipselectionisveryimportant,andcanhelppreventairentrapment.When

using metal tips, use 21 gauge (0.020”) or larger if the application permits,

as they will allow small air bubbles to purge through.

 • Taperedpolyethylenetipsareagoodchoiceinanysize.Theyallowfluidto

flow freely through the tip to purge and prevent air bubbles from collecting.

Tapered tips typically range from 14 gauge to 27 gauge.

 • Useavalvecontrollerwithapurgefunctionthatallowstheusertobleed

any air in the system quickly and easily.

 • Useafluidtankwithaconstant-bleedairregulatortopreventfluctuations

in pressure and shot size.

 • Installafilter/regulatorbetweentheplantairsupplyandthedispensevalve

to remove any residual moisture from the system – this is especially import-

ant when working with cyanoacrylates.

“Flash” inside hub of low-quality

tip restricts fluid flow.

High-quality tip provides unob-

structed fluid path.

Tips should be selected based on the

specific fluid and application.

Correct tip selection is very important to dispense valve performance. The best

choice is using a tip with the largest possible internal opening for the intended appli-

cation. This will prevent air bubbles from forming.

Tip quality has a surprisingly large effect on the accuracy and uniformity of fluid

deposits – especially in critical applications where very small deposits are required.

Trying to save a few cents on lower-quality tips may result in costing more in the

long run once factors such as fluid waste and additional operating time are factored.

Even the most precise dispensing system will not produce consistent results if the

tip – the last path the fluid travels before it reaches the part – is obstructed by debris

from the molding or machining process.

Which of these components would you rather use?

9 www.nordsonefd.com

Should You Replace Your Current Dispense Valve System?

In the middle of coping with day-to-day production challenges, it can be difficult to calculate just how

much poor valve performance is really costing you.

However, doing so could save you money, increase production, reduce bottlenecks, and improve the

overall quality of your products. It may be worth tracking valve-related problems for a week or so, then

converting them into a yearly expenditure.

Some key points to analyze:

 • Howmuchtimeandlaborareyouspendingonvalvesetup?

 • Howmucharevalve-relateddowntimeandmaintenancelaborcostingyouperyear?

 • Ismostofyourvalvemaintenancescheduled,ordoyourvalvesbreakdownunexpectedly?

 • Ifyourcurrentvalvesmakeithardtocontrolshotsize,howmuchareyouspendingonvalve-

related rework, rejects, and cleanup?

 • Areyourdispensingstationscausingabottleneck?

 • Areyouwastingexpensiveassemblyfluid?

 • Doyouhaveanyvalve-relatedsafetyissues–spills,fumes,storage/disposalofhazardouswaste?

Depending on the responses you come up with, the most cost-effective solution may be to install a

more accurate and reliable dispense valve system.

In many instances, the savings will pay for the new equipment in a surprisingly short time and continue

to reduce operating expenses year after year.

10. How Often Do Your Valves Require Maintenance?

All valves will eventually require maintenance, but some designs require more

frequent repair than others. Here are some things to consider:

 • Howoftenismaintenancerequired?Whileawell-engineeredvalvedesign

will go tens of millions of cycles without any degradation in performance or

accuracy, others may require maintenance after they have been shut down

over the weekend, or even at the start of every shift.

 • Ifvalvemaintenanceisrequired,canitbeperformedonsite,ordoesthe

valve have to be returned to the manufacturer?

 • Ifservicecanbeperformedonsite,howcomplicatedisit?Canyousimply

removethefluidheadwithoutdismountingthevalve?Ordoesthevalve

have to be removed from the mounting fixture and taken apart? With some

high-performance designs, routine maintenance is as simple as replacing the

dispense tip.

 • Sparepartsprovidedbylocalmachineshopsmaynotalwaysbereadily

available. This delay could lead to line downtime when replacement parts

are needed. Using engineered products that have an abundant supply of

replacement parts can add significant value.

If you’re spending too much time and money keeping your valves up and

running, it might be worth looking at a more reliable, low-maintenance design.

Required maintenance can greatly vary

between valve systems.

Thanks for Reading!

We hope you found this information helpful.

If you are not satisfied with the performance of your current dispense valve system, we invite you to discuss

your application with one of our experienced Product Application Specialists.

EFD offers dispensing solutions for the following applications:

There is no cost or obligation for this service, and your information will be treated as confidential. Qualified

applications may be eligible to try an EFD dispense valve system under our no cost-evaluation program.

For more information, visit Nordson EFD on the web at www.nordsonefd.com, www.facebook.com/NordsonEFD

or www.linkedin.com/company/nordson-efd or contact us at info@nordsonefd.com,

+1 401.431.7000 or 800.556.3484.

• Catheters

• Pacemakers

• Contactlensesandpackages

• Vialfilling

• Syringelubrication

• Stentcoating

• Membranes

• Surgicalanddentaltools

• Diagnosticequipment

• Respirationdevices

• Defibrillators

• Hearingaids

• Pillsandmedicines

• NeedleBonding

• BloodCollectionTubes