Knowledge Kit
Bespoke Foam Pigs for Large-Bore Pipelines with Over 100 Bends
Project Overview
Royal Poly Products was engaged to design and manufacture a bespoke foam pig capable of navigating over 100 consecutive 90-degree, small radius bends in an onshore large-bore pipeline system. The challenge was not just mechanical but strategic: these pigs needed to function across multiple operational phases — flooding, hydrotesting, and dewatering — while remaining inside the pipeline for extended periods.
- Core breakage under pressure
- Foam degradation over extended dwell times
- Ineffective dewatering due to pig distortion
This risk was unacceptable for the client, especially with the pig needing to be pushed back from the receiver to the launcher using dry air after hydrotest completion — a rare and reverse operation.
Innovation in Design
Royal Poly Products engineered a proprietary full-foam structural core, avoiding the use of conventional soft inserts while retaining the necessary flexibility to handle tight bends. Key design elements included:
- Special Density Foam Core: Constructed using a medium-density polyurethane foam that provided structural resilience without compromising bendability.
- Monolithic Adhesion Strategy: The core and outer foam structure were bonded using a proprietary technique ensuring uniform stress distribution, avoiding internal shear or delamination.
- Failure-Mode Simulation: Before manufacture, the pig design was simulated using FEA software to evaluate deflection, compression, and torsional response across multiple bend scenarios. This enabled:
- Establishing safe pressure limits for pig movement
- Defining maximum allowable velocity
- Ensuring integrity throughout bidirectional travel
Execution & Results
- The pigs successfully traversed over 100 bends during the initial flooding run, displacing air with water in a single pass.
- After hydrotesting, the pigs were reversed through the pipeline using dry air, achieving bulk dewatering without structural degradation.
- The pigs remained intact, and their performance was validated visually and dimensionally post-operation.
Why It Stands Out
Royal Poly Products custom-designed and manufactured a high-density, fully coated polyurethane foam pig, optimised for:
- Bidirectional pigging in a large-bore pipeline without foam failure
- Use of simulation to set pigging parameters, a capability usually not offered by manufacturers
- A new standard in collaboration between pig manufacturers and pigging contractors
- Client feedback highlighted Royal’s engineering depth, agility, and problem-solving mindset
Client Quote
“This was more than just pig supply — it was a true engineering partnership. Royal Poly Products enabled us to predict outcomes, reduce risk, and execute flawlessly across three pipeline operations using the same tool.”
Key Takeaways
- Foam pigs don’t need soft cores to be flexible — they need the right engineering.
- Bidirectional pigging can be safe and effective with smart core design.
- Simulations in pig design can save cost, prevent failure, and ensure project success.