Enhancing Process Reliability: How Instarmac Group PLC Eliminated Frequent Downtime with the Vortex Clear Action Gate

Introduction

Instarmac Group PLC is a market-leading specialist in the manufacture of cement and bitumen-based products for the construction and highway repair/maintenance industries. A core product in their portfolio is an instant road repair material, which relies on a precise and demanding production process.

The process involves the lean phase vacuum transfer of "skim" bitumen-coated limestone, ranging from 3mm to 10mm in size. This sticky material is moved from an external bulk hopper to an internal receiving weigh hopper in batches of up to one tonne. Following this transfer, the material is discharged into a heated mixer, where pigment powders and additional liquid bitumen are added to create the final product. A critical component in this system is the valve on the outlet of the vacuum hopper, which must operate reliably under challenging conditions.

Challenge

Instarmac was using an inflatable seal butterfly valve at the vacuum hopper's outlet. This component became a source of significant operational inefficiency and frequent maintenance challenges. The sticky nature of the bitumen-coated limestone, combined with the material headload, presented several problems for the butterfly valve:

• Operational Failure: The valve frequently failed to open against the weight of the material, causing process interruptions. When it did actuate, the disc’s movement would compact the sticky material, obstructing flow from the hopper.
• Sealing Integrity: Material would become trapped between the valve’s blade and its inflatable seal. This prevented the valve from closing properly, which compromised the vacuum pressure essential for the transfer process and caused limit switches to fail, disrupting system automation.
• Mechanical Stress: The repeated struggles to actuate under load led to severe mechanical failures, including twisted and snapped valve shafts.

These issues resulted in a predictable failure cycle, requiring maintenance intervention approximately every 12 weeks. This recurring downtime led to lost production time, increased labour costs, and the expense of replacement parts.

Solution

To address these persistent challenges, Instarmac implemented the Vortex Clear Action Gate. The first gate was installed at the beginning of 2024 to replace the problematic butterfly valve.

The Clear Action Gate is engineered specifically for applications involving differential pressure and difficult-to-handle materials. Its design directly counters the issues Instarmac faced:

• Positive Seal and Actuation: The gate utilises "live loaded," wear-compensating hard polymer seals. These seals are shielded from the material flow and maintain a positive seal against pressure. The blade slides without obstruction, eliminating the material compaction issues associated with the butterfly valve’s rotational disc.
• Material Handling: The design eliminates metal-on-metal contact, preventing the galling and seizing that can occur with abrasive or sticky substances. As the blade closes, its self-cleaning action forces material away from the sealing surfaces and back into the process line, ensuring a complete and reliable closure every cycle.
• Durability: The component was supplied with a special service inlet customised for the application, ensuring seamless integration and optimal performance within Instarmac's existing system.

The immediate and consistent success of the initial installation prompted Instarmac to purchase two additional Clear Action Gates in the second quarter of 2024, standardising the solution across their lines.

Results

The transition to the Vortex Clear Action Gate delivered substantial and immediate improvements to Instarmac's production process.

• Elimination of Downtime: Since the installation of the first unit, there have been zero operational issues. The 12-week failure cycle that had defined the previous setup was completely eliminated.
• Increased Reliability: The Clear Action Gate consistently opens and closes against the full headload of sticky material without fail. This has resolved all previous issues related to material compaction, incomplete sealing, and mechanical stress.
• Improved Process Efficiency: With a reliable, dust-tight seal, the vacuum transfer system now operates at optimal efficiency. The dependable actuation and position confirmation from the gate's limit switches have enhanced the automation and control of the entire batching process. This has resulted in a significant reduction in maintenance labour and component replacement costs.

Conclusion

The recurring operational failures and maintenance demands of the inflatable seal butterfly valve presented a significant obstacle to Instarmac Group PLC's production efficiency. By implementing the Vortex Clear Action Gate, the company found a durable, long-term solution that directly addressed the core challenges of handling a sticky, abrasive material under pressure.

The investment has delivered a clear return by eliminating chronic downtime and its associated costs. The successful integration of the Clear Action Gate demonstrates the value of specifying components engineered for demanding applications, affirming the gate's superior performance and reliability.

Contact Us today to see how we can help solve your material handling issues!