BUSINESS ENQUIRY

Corrosion Under Pipe Support in Singapore: Detection, Risks & Prevention Strategies

Sub-surface corrosion of the under-supporting pipes in Singapore is a severe but unnoticeable hazard to piping systems in offshore platforms, refineries, marine terminals, and petrochemical plants. This type of deterioration is referred to as CUPS (or Touch Point Corrosion), and it takes place when moisture, salt deposits, and debris is trapped between pipes and their supporting structures, and this process increases the speed of the oxidation process and has been seen to be invisible to the naked eye.
Since Singapore is a tropical area of high humidity with a marine environment having a high salinity, pipe support corrosion inspection in Singapore is required to maintain asset integrity, safety in operation, and regulatory compliance.

What is Corrosion Under Pipe Support (CUPS)?

CUPS means localized metal loss that takes place at the pipe/support interface. This is a natural trap of the corrosive agents, and so, it is one of the hardest damage mechanisms to control in industrial plants.

Common Causes:

  • Water and salt deposition: Stagnant moisture forms an incessant electrolyte in corrosion.
  • Coating breakdown: The protective paint is worn out at support points by friction due to thermal expansion.
  • Crevice Corrosion: The slot between the pipe and the beam is a classic crevice, which enhances the rate of chemical attack.
  • Lack of Ventilation: Support designs that don’t allow for evaporation keep the metal perpetually damp.
Undetected corrosion concealed beneath supports may cause unpredictable leakages, disastrous structural collapse, and costly emergency closure.

Why CUPS is a Major Concern in Singapore

The industrial environment of Singapore is very vulnerable because of its geographical position. Humidity and salty air are the main features of the region i.e. every slight rupture in the coat of a pipe may turn into a well in several months.

High-risk environments include:

  • Onshore rigs and offshore piping.
  • Jurong Island Refineries/ Petrochemical plants.
  • Tuas marine terminals and shipyards.
  • FPSO units (Floating Production Storage and Offloading).
Periodic inspection of pipeline corrosion in Singapore is not a preference of safety- it is a prerequisite of the integrity of assets.

Where Corrosion Under Pipe Supports Occurs

Corrosion Under Pipe Support (CUPS) is a localized risk that flourishes at any place where the pipe is in contact with a second surface. These points of contact, commonly known as touch points, form micro-crevices that serve as sources of attraction for moisture and industrial contaminants. The high humidity of Singapore means that these spaces do not have the opportunity to dry out, and thus, in some of the most important industrial places, the metal is lost more rapidly:

Oil, Gas & Petrochemical Facilities

Refineries use process piping that is frequently stacked closely on racks of pipes a story high. The inspection of corrosion of refinery pipeline pays attention to the so-called touch points where the pipes are lying on I-beams or are fastened by saddle clamps.

Marine & Offshore Structures

The most aggressive cause of CUPS is saltwater exposure. The inspection of offshore piping corrosion is important in the prevention of seawater cooling lines breakdown or dangerous process leakages on FPSOs.

Industrial & Power Facilities

Turbine cooling systems and boiler feed lines are vulnerable to CUPS, particularly in high-vibration locations that may greatly speed up the coating wear.

Inspection Methods for Detecting CUPS

The main problem is that it is difficult to detect corrosion without having to lift a live pipe. In Standard Non-Destructive Testing Pte. Ltd. (SNDT), we use modern technologies in order to look beneath the surface.

1. Ultrasonic Testing (UT) & Phased Array (PAUT)

Pipe supports Ultrasonic testing is an ultrasonic sound testing method to determine the wall thickness. Best PAUT may offer a cross-sectional image of the profile of corrosion that may be utilized to measure the depth with accuracy.

2. Guided Wave Ultrasonic Testing (GWUT)

The final screening tool is GWUT (or Long-range UT). It is an echo of sound that travels the full length of the pipe, enabling the inspectors to identify corrosion at various support points at the same time without the need of stripping off the insulation or lifting the pipe.

3. Eddy Current Testing (ECT)

ECT is very useful in revealing surface-breaking cracks and coating corrosion in conductive materials and is normally utilized as a supporting indicator for non-ferrous piping.

4. Corrosion Mapping

Technicians make a heat map of the wall thickness of pipes using robotic scanners. This is a digital record, which is required in reliability-centred maintenance (RCM) and future trend analysis.

Risks of Ignoring Corrosion Under Pipe Supports

  • Pipeline spillages: Pits may easily develop into pinholes.
  • Structural failure: Badly strengthened pipes can bulge under the weight of their contents.
  • Environmental fines: Hazardous spills lead to high NEA fines and prosecution in Singapore.
  • Unexpected outages: Repairing one support point in case of failure may be ten times more expensive than planned repair.

Prevention & Mitigation Strategies

  • Protective Coatings: Coatings that are high-performance, epoxy or glass-flake-epoxy, and intended to be used in immersion service.
  • Better Design: The use of non-metallic composite pipe shoes with half-round rods to reduce the number of contacts and avoid stagnation of water.
  • Protective Wraps: Coating the supports with hulls made of fiberglass composite to form a non-corrosive barrier.
  • Routine Monitoring: Risk-Based Inspection (RBI) program focused on the lines with high risks.

Compliance & Industry Standards

In Singapore, professional inspections should be based on international codes so that they can be legally recognized:
  • Standard API 570: Piping inspection, repair, and alteration standard.
  • ASME B31.3: Process piping code.
  • ISO 9001 & SAC-SINGLAS: Assuring the quality of the competence of the provider of NDT services.

FAQs: Corrosion Under Pipe Support (CUPS) in Singapore

Q1. What is Corrosion Under Pipe Support (CUPS)?
Ans: CUPS is a localized corrosion that takes place at the point of contact (touch point) between a pipe and the support. It commonly occurs due to moisture, salt and debris accumulating in the gap, forming a corrosive microclimate that corrosively attacks the metal.
Q2. What makes CUPS a high-risk in Singapore?
Ans: Singapore has a tropical climate that is characterized by a lot of humidity and rainfall. Used together with the salty air of our industrialized coastal areas (such as Jurong Island and Tuas), it forms the ideal electrolyte to undergo rapid oxidation at the pipe touchpoints.
Q3. Is it possible to recognize CUPS without raising the pipe?
Ans: Yes. Recent Advanced NDT techniques, such as Guided Wave Ultrasonic Testing (GWUT) and Medium Range UT (MRUT), enable the inspector to screen corrosion at support points whilst the pipe is in operation and on its support.
Q4. What is the best NDT approach to CUPS?
Ans: This is determined by the size of the pipes and access. Guided Wave (LRUT) is ideal in long-range screening, whereas Phased Array Ultrasonic Testing (PAUT) or EMAT (Electromagnetic Acoustic Transducers) can be used to locate a specific touchpoint to map it with high-resolution images without the use of a liquid couplant.
Q5. Can CUPS be prevented by design?
Ans: Absolutely. The prevention methods entail the implementation of non-metallic pipe shoes, installation of the composite wear pads, and provision of the pipe supports to facilitate good drainage to avoid the accumulation of water.
Q6. What are the symptoms of CUPS on the visual assessment?
Ans: CUPS can be invisible, but indications of it may be seen through rust streaking (under the support) or bulging of the pipe (as a result of rust expansion) or by coating failure visible at the point of contact.
Q7. What is the recommended frequency of inspection of pipe supports in a refinery?
Ans: This is normally dictated by a Risk-Based Inspection (RBI) plan. Corrosive environments that have very high-risk lines (containing hazardous fluid or high-pressure fluid) are usually inspected every 3 to 5 years.

Conclusion

This offshore, marine, petrochemical, and industrial piping issue, corrosion under pipe support, is a major concern of integrity as reported in Singapore. The damage is usually hidden, thus it may be left to develop before a disastrous leakage or structural failure.
 
Certified inspectors of Standard Non-Destructive Testing Pte. Ltd. (SNDT) can identify CUPS in its early stages by using superior inspection procedures like Guided Wave Testing, PAUT, and Corrosion Mapping. Regular inspection and preventive maintenance is a foolproof approaches that is not only the means to save your critical infrastructure, but also ensures safety compliance and considerably lowers the chances of unplanned downtime.
 
Next Step: Does it have any piping pieces that are not visible but have not been evaluated in the recent past? Contact SNDT today to have a professional CUPS Risk Assessment carried out to ensure your assets remain safe and functional.