In heavy-duty hydraulic press operations, uptime is the metric that matters most. As presses age, standard NBR/fabric V-packing installations begin to fail in three predictable ways: extrusion, wear and abrasion, and low-pressure leakage.
Extrusion is the most common; as bronze bushings wear and the extrusion gap grows, NBR/fabric female adapters can no longer bridge the gap under pressure, and packing extrudes into the clearance.
A ram worn to an hourglass profile makes the problem worse. Wear and abrasion follow a similar pattern, as scoring, pitting, and corrosion on the ram act as an abrasive on every cycle that standard intermediates resist poorly
Low-pressure leakage is a separate issue: on the positioning stroke, the ram runs with little or no pressure, fluid bypasses the stack, and the ram weeps oil. Because it stems from a design gap rather than packing wear, this failure mode is often misdiagnosed.
For one operator running an aging press fleet, these failure modes had become a steady drain on production: seal replacements were running at a rate of roughly one per month, with downtime exposure estimated at $600,000 annually and reliability continuing to decline.
Working with the customer's engineering team, System Seals developed Elite V-Packing, a diagnostics-driven, application-specific sealing platform rather than a standardized catalog configuration.
The Challenge: To design a V-packing system
Design a V-packing system that could address extrusion, wear and abrasion, and low-pressure leakage in an aging press fleet, without relying on a one-size-fits-all catalog configuration.
The Solution:
System Seals engineered each configuration around the actual wear patterns, load profiles, and failure data of the specific press, then refined it using extracted seal analysis over successive service intervals.
The resulting stack has three functional positions: a POM or PA female adapter at the base, stiffer than standard NBR/fabric, with a centering guide ring profile that splits into wedges to handle worn bores and hourglass-worn rams; H-polyurethane intermediates at the center, which hold up better against abrasion than NBR/fabric and can be configured with thinner V-rings where low-pressure leakage is the dominant issue; and a proprietary W-profile male adapter at the top, which acts as an active sealing lip adding sealing force independent of system pressure.
- Female Adapter: Standard NBR/fabric is replaced with a stiffer POM or PA adapter for extrusion resistance. A Centering Guide Ring profile splits into wedges that expand under pressure to handle worn bores and hourglass rams.
- Intermediate Sealing Elements: H-Polyurethane intermediates replace NBR/fabric and hold up far better against abrasion. Where low-pressure leakage is the issue, one heavy-duty ring can be swapped for thinner V-rings that seal at lower pressures.
- Male Adapter: A proprietary W-profile replaces the flat standard design. It works as an active sealing lip that adds sealing force at the top of the stack, independent of system pressure.
The Result:
Elite V-Packing reduced annual seal replacement events from twelve to four, a 67% reduction, and extended service intervals roughly threefold, from monthly to quarterly.
The customer recovered an estimated $400,000 in uptime value annually, alongside improved resistance to scoring and surface damage and more consistent sealing under variable and peak loads.
