Test Case – Field Performance Evaluation of Pexgol

Field evaluation of Pexgol PE-Xa pipes under highly abrasive iron ore slurry conditions at Cauê Mine.

Estudo de Caso Nº

189 Cliente

Vale

Brazil

2025

Condições de Trabalho

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Solução Pexgol

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Aplicação

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Comprimento

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Categorias

Minério de Ferro, Mineração, Lama

Operational Test Parameters

Flow Rate: 700 tons per hour
Installed Pipe: Pexgol 500 mm – SDR 11
Wall Thickness: 45,4 mm
Replaced Pipeline: Steel pipe with polyurethane lining
Steel Thickness: 3/16” (4,95 mm)
Polyurethane lining thickness: 1/2”
Polyurethane properties: Tensile strength: 5800 PSI | Tear resistance: 480 PSI | Hardness: 85 Shore
Maximum Operating Pressure: 150 PSI
Operating Temperature: 33 °C
Slurry Composition: Iron ore slurry with 48–60% iron and silica content in water
Particle Size: D80 = 150 microns

Test Timeline

Start of Test: December 15, 2022
First Inspection: May 3, 2023
Second Inspection: December 2, 2025

The Challenge

The Cauê Mine, operated by Vale in Brazil, has a tailings transport pipeline several kilometers long with a diameter of 18 inches. The existing pipeline is constructed from carbon steel internally lined with polyurethane (PU).

Due to the highly abrasive nature of the iron ore slurry, the pipeline requires frequent and costly maintenance. This includes periodic replacement of full pipe sections or refurbishment of the internal polyurethane lining.

Given the significant capital investment required to replace the entire pipeline, Vale decided to first conduct a field performance test using Pexgol crosslinked polyethylene (PE-Xa) pipes. The objective was to evaluate the pipe’s resistance to abrasion and its operational performance under real operating conditions.

The test installation was performed in the Grinding Area (Milling Plant) of the Cauê Mine.

Test Objective

The objective of the test was to perform Non-Destructive Testing (NDT) on a 3,000 mm long Pexgol pipe section installed in the discharge pipeline of pumps BP-1920EE-05/06, responsible for feeding tank CX-1491EE-09. The installation took place on December 15, 2022, and the evaluation aimed to verify the pipe’s structural integrity and wear performance during operation. Additionally, the test provided technical support to the Cauê Mine engineering team in their evaluation process for potential pipeline replacement decisions.

Inspection and Testing Methodology

During the monitoring period, the following inspections and tests were performed:

Visual Inspection (VI)
Ultrasonic Thickness Measurement (UT)
These tests were conducted in the Grinding Plant area of the Cauê Mine to identify any operational deviations or anomalies during pipeline service. The inspections focused on detecting:
Premature wall thickness reduction
Material deformation
Operational anomalies that could compromise the pipeline integrity All inspections were conducted in accordance with SAT-3833 standard procedures and applicable technical reference documents.

Wear Rate Results

Average wear rate measured during inspections:

Point 01: 0.6 – 1.0 mm/year
Point 02: 0.9 – 1.3 mm/year
Point 03: 0.8 – 1.2 mm/year
Point 04: 0.4 – 0.8 mm/year

Conclusions

The ﬁeld test was considered successful, as the wear rate measured in the Pexgol pipe was lower than the expected wear behavior of the previously installed steel pipe with polyurethane lining, when considering the available wall thickness and operational conditions. No leaks, structural failures, or operational anomalies were observed during the testing period. Considering that the installed pipe is Pexgol SDR 11, capable of operating at 220 PSI, and accounting for an allowable 40% wall thickness wear, the estimated service life of the pipe under these operating conditions is approximately: 12 years. This result demonstrates the excellent abrasion resistance and operational reliability of Pexgol pipes for highly abrasive slurry transport applications in mining operations.