Top 5 Seal Failures in Nordson® Systems and How to Prevent Them

Nordson® hot melt and fluid dispensing systems, such as the popular ProBlue® series, are widely used in packaging, labeling, and product assembly. However, like all precision equipment, their performance heavily depends on the integrity of internal seals. A failed seal can lead to downtime, product contamination, and costly repairs.

In this article, we’ll cover the top 5 seal failures in Nordson® systems, what causes them, and most importantly, how to prevent them with proper maintenance and quality replacement seals.

1. Pump Shaft Seal Failure

     Common Symptoms:

• Hot melt leakage around the pump housing
• Fluctuating pressure or flow rate
• Unexpected system shutdowns

     Causes:

• Worn or degraded seal material (common in high-temp operations)
• Improper seal installation
• Excessive backpressure or pump overload

     Prevention:

• Use high-temperature resistant seals like Viton® or PTFE composite seals
• Always follow OEM torque specs during installation
• Replace seals proactively based on operating hours

2. Heated Hose Seal Leakage

     Common Symptoms:

• Hot melt dripping from hose fittings
• Burnt glue odor or smoking
• Inconsistent adhesive application

     Causes:

• Thermal cycling leading to seal hardening or cracking
• Over-tightening of hose fittings
• Chemical degradation from incompatible adhesives

     Prevention:

• Choose seals rated for thermal cycling (e.g., silicone + PTFE hybrid seals)
• Inspect hoses during each maintenance cycle
• Ensure compatibility of seal materials with specific adhesives used

3. Tank Lid or Cover Gasket Failure

     Common Symptoms:

• Glue fumes escaping from the tank
• Burn the residue near the lid
• Reduced pressure build-up in the system

     Causes:

• Compression set of the rubber gasket over time
• Improper lid closure or misalignment
• Use of substandard aftermarket gaskets

      Prevention:

• Replace gaskets regularly using OEM-grade or equivalent gaskets
• Use reinforced fiber or graphite composite gaskets for better durability
• Ensure uniform lid tightening using a cross-pattern method

4. Nozzle Seal Wear

     Common Symptoms:

• Dripping nozzles or poor shut-off
• Uneven or messy glue lines
• Manual cleaning is needed more frequently

     Causes:

• Abrasive fillers in adhesives
• Incorrect nozzle disassembly/reassembly
• Seals are not rated for cycling frequency

      Prevention:

• Use PTFE or ceramic-reinforced seals for longer nozzle life
• Clean nozzles with approved tools only
• Train operators on correct maintenance procedures

5. Filter Housing Seal Leakage

     Common Symptoms:

• Melt leakage near the filter area
• Reduced flow or clogged system
• Difficulty maintaining system pressure

     Causes:

• Hardened O-rings or seals from heat exposure
• Seal incompatibility with filtering adhesive
• Incorrect installation

      Prevention:

• Choose FKM (Viton®) or HNBR seals for high-temperature stability
• Replace seals when replacing filters (don’t reuse)
• Store spare seals in a cool, dry environment to prevent premature aging

Bonus Tips: How to Extend Seal Life in Nordson® Systems

1. Schedule monthly seal inspections on ProBlue and similar units
2. Maintain stable operating temperatures—avoid frequent overheating
3. Use compatible aftermarket replacement seals from trusted manufacturers
4. Train staff on correct assembly/disassembly techniques to prevent seal damage
5. Log service history and track MTBF (mean time between failures) of seals

High-Performance Seal Replacements for Nordson® Equipment

At XHH seals, we offer precision-engineered replacement seals and gaskets compatible with Nordson® ProBlue, DuraBlue®, VersaBlue®, and other hot melt dispensing systems. Our seals are manufactured using high-grade materials like:

• PTFE, Viton®, FKM, HNBR, and UHMWPE
• Customized O-rings, flat gaskets, and dynamic seals
• Exact-fit alternatives to OEM parts at competitive pricing

? Contact us at [xhh@xhh-smartech.com] to get a quote or request a compatibility guide.

Frequently Asked Questions (FAQs)

Q1: Can I replace Nordson® seals with aftermarket alternatives?

Yes, as long as the replacements match OEM specifications and use equivalent or superior materials.

Q2: How often should seals be replaced in ProBlue® systems?

Typically, every 3–6 months, depending on usage, adhesive type, and operating temperature.

Q3: What are the signs of seal degradation?

Leaks, odor, inconsistent adhesive flow, and increased maintenance frequency are common indicators.

Final Thoughts

Seal failures in Nordson® systems are common but avoidable with the right knowledge and replacement parts. Regular maintenance and investing in high-quality seals will improve uptime, reduce costs, and prolong the life of your hot melt system.