Early Detection of Weak Spots in Glass Reinforced Plastic Pipelines

We are seeking cost-effective and innovative solutions to perform the detection of weak spot and joints of GRP pipelines in desalination plants, without disrupting the water treatment process. We welcome any of the following approaches or other innovative methods that meet our objectives:

1. Non-invasive and non-destructive methods (e.g., ultrasonic testing, thermography and radiography) to inspect pipelines externally, combined with instrumentation, drones or robotic platforms to enable safe access to hard-to-reach areas.
2. Methods capable of remote inspection, such as acoustic testing and transient pressure monitoring.
3. Methods that allow large area inspections from a distance given the large quantity of GRP pipelines in desalination plant, preferably those enabling inspection of elevated pipelines without requiring scaffolding or Mobile Elevated Work Platforms.
4. While external inspection methods are preferred, solutions may include in-line inspection method, provided they do not compromise water quality.

Successful implementation of these solutions could yield the following benefits:

1. Safeguarding of plant operations by prevention of catastrophic failures.
2. Decreased operational costs by optimising maintenance schedules and reducing emergency repairs.
3. Improved safety by preventing hazardous pipe failures and reducing the work at height needed to inspect pipelines.
4. Improved plant reliability by ensuring consistent water supply.
5. Extended lifespan of GRP pipeline infrastructure by more accurately identifying area of weakness thereby delaying the need for costly replacements.

A. Operational Requirements

1. The proposed methods must be non-destructive and shall not compromise the structural integrity of existing pipelines.
2. The solution should ideally operate without interrupting treatment processes and require minimal modifications to existing pipelines and fixtures.
3. Process water quality standards must be maintained throughout the inspection activities, with no contamination or degradation permitted.
4. The preferred inspection method should enable long-distance, remote or autonomous monitoring, which may include the use of extenders, drones or robotic platforms, thereby eliminating the need for scaffolding or Mobile Elevated Work Platforms when inspecting elevated pipelines.
5. Results can be easily interpreted and shared with plant personnel, without requiring the procurement of specialised equipment or external services.

B. Implementation Context

1. The solution shall be applicable across pipe diameters ranging from 150mm and 2,400mm, though we would consider multiple solutions for different pipe diameter ranges. The following pipeline sections would be available for pilot testing:
   1. Up to 100 m of GRP pipeline, 2,400 mm in diameter, serving as the header for the ultrafiltration flushing lines.
   2. Up to 100 m of GRP pipeline, 2,200 mm in diameter, serving as the header for the seawater RO system feed.
   3. Up to 100 m of GRP pipeline, 350 mm in diameter, serving the disc filter backwash line.
   4. Several pipe joints identified as susceptible to single-point failures.
2. The solution shall be applicable to pipelines that are typically filled, with operating pressures ranging from 2 to 6 bars across treatment processes. The solution must not require the pipelines to be drained.
3. For pipelines exceeding 1,200mm in diameter, there are access manholes for the insertion of devices. These manholes are typically either 500mm or 800mm in diameter.
4. Smaller pipes typically lack direct access points, though it may be possible to insert devices through flanges designed for analysers and gauges.
5. Photo examples of pipeline defects and various pipeline configurations found in PUB desalination plants are shared under the Resource section below.

By the end of the pilot, the project should aim to develop and demonstrate an effective inspection system for detecting weak spots and joints in GRP pipelines for at least one desalination plant. The demonstration must validate the following:

1. The solution can accurately detect weak spots and joints in GRP pipelines and provide an assessment of their severity.
2. The inspection system must be capable of operating without disrupting the water treatment process and maintain compliance with all relevant water quality standards.
3. The solution must demonstrate the ability to inspect elevated sections up to 6 metres high, without requiring scaffolding or Mobile Elevated Work Platforms.
4. After the completion of inspection, a report detailing the detected weak points and joints shall be produced.

The pilot project is to be completed within a period of 18 months.

The suggested project scope and timeline are outlined below, noting that specific timelines and activities may vary depending on the technology type and maturity. You may propose alternative timelines and activities.

Milestone 1: System Development and Laboratory Testing (3-4 months)

1. Develop and calibrate the inspection system
2. Validate detection capabilities on test specimens with known defects
3. Establish inspection protocols and reporting framework

Milestone 2: Initial Field Trials (4-5 months)

1. Deploy the system in an identified section of the desalination plant
2. Refine inspection procedures and data analysis methods
3. Validate system performance against conventional inspection methods

Milestone 3: Extended Field Implementation (2-3 months)

1. Conduct inspections across various pipeline configurations
2. Analyse inspection data and prepare reports
3. Evaluate system performance and operational efficiency

If the pilot demonstrates successful outcomes, PUB would be interested in implementing the solution through a service model. Solution providers which are not based in Singapore would need to set up operations in Singapore or partner with a Singapore-based contractor to deliver the service.