Alternative Solutions
Competitive Solutions to Corrosion Under Pipe Supports (CUPS)
The challenge of Corrosion Under Pipe Supports (CUPS) has been a longstanding issue for the gas and petrochemical industries, with estimated annual costs reaching around $1.5 billion, as reported in a study by NACE (National Association of Corrosion Engineers). Beyond the financial implications, the potential risks to human life and safety are immeasurable. To address this problem, various solutions have been introduced to the market, each with its strengths, weaknesses, and costs. The SmartPad System distinguishes itself by offering a combination of benefits no other solution can match. These benefits include:
- Effective pipe external corrosion protection.
- Speedy installation, removal, and reinstallation.
- Allowing visual inspection for external corrosion at minimal cost.
- Drastically reducing total ownership cost.
The following is a discussion of some notable solutions to the CUPS problem available on the marketplace today, and such alternatives include:
- Welded Metallic Wear Pads
- Metallic Rods / Round Bar
- Plastic Rods
- Wraps, Liners, & Sheets
- Epoxied-On FRP Wear Pads
Each of these solutions comes with its own set of strengths and weaknesses, and their effectiveness can vary depending on the specific application and environmental conditions. It’s essential to evaluate these options carefully to determine the most suitable solution for addressing the CUPS problem in a given context. Here’s a closer look at their pros and cons:
Welded Metallic Wear Pads
Metallic wear pads, or wear plates, are saddle-shaped pads positioned underneath a pipe to cradle it. They can either be fully welded or tack-welded at the contact regions of the pipe, effectively shielding the pipe’s protective paint coating from friction. While they offer a potentially effective solution to specific challenges, they also have some drawbacks:
- Primarily Addressing Consequences: It’s essential to acknowledge that these metallic supports primarily address the consequences of corrosion rather than preventing its onset. They do protect the pipe’s paint coating from friction caused by pipe movement and vibration, and they essentially increase the pipe’s wall thickness by merely adding more material to it. However, the issue of galvanic corrosion caused by metal-to-metal contact still persists, and corrosion will form. This solution only delays the inevitable.
- Installation Challenges: The installation process presents obstacles, including the requirement for line shutdowns, welding permits, and the engagement of skilled welders, resulting in both production disruptions and increased installation costs.
- Safety Concerns: The entrapment of moisture in crevices between the pad and the pipe can foster the development of hidden corrosion cells that are challenging to identify, potentially leading to pipe failure and even more serious consequences. Such failures and their tragic consequences have been well-documented time and again by the U.S. Chemical Safety Board
Comparison
| Metallic Wear Pads | SmartPad System |
|---|---|
| Metal-to-Metal Contact | Eliminates Metal-to-Metal Contact |
| Installation Requires Experienced Welders | Lower Skilled Laborers Can Install with Minimal Training |
| Welding Permit Required | No Permits Required |
| Line Shutdown Probable | No Line Shutdown Needed |
| Faulty Installs Possible | Minimal Chances of Installation Failure |
| Costly Inspections | Visual Inspection Possible Any Time at Minimal Cost |
Metallic Rods / Round Bar
Metal round bars have been employed to elevate pipes above their supports, with the aim of improving airflow and reducing crevice corrosion. However, this approach comes with its own set of challenges:
- Point-Loading Stress: Metal round bars can point-load the pipe, concentrating stress at the contact points. This concentrated stress not only erodes the protective paint coating on the pipe but can also jeopardize the pipe’s own structural integrity.
- Galvanic Corrosion: The use of metal round bars doesn’t effectively address the concern of galvanic corrosion stemming from metal-to-metal contact, which remains a persistent problem with this approach.
Consequently, this solution can create more issues than it resolves.
Comparison
| Metallic Round Bar | SmartPad System |
|---|---|
| Metal-to-Metal Contact | Eliminates Metal-to-Metal Contact |
| Point-Loading Damages Pipe Structure & Paint Coating | Saddle Shape Protects Pipe Structure & Paint Coating |
| Installation Could Require Experienced Welders | Lower Skilled Laborers Can Install with Minimal Training |
| Welding Permit Required | No Permits Required |
| Line Shutdown Probable | No Line Shutdown Needed |
| Faulty Installs Possible | Minimal Chances of Installation Failure |
Plastic Rods
Plastic round bars, or half-round rods, are commonly used to elevate pipes above their supports, promoting better airflow and mitigating crevice corrosion in piping systems. As they are made from non-metal materials, these round bars prevent galvanic corrosion resulting from metal-to-metal contact, making them a viable option to protect piping systems from corrosion at the pipe support points. However, plastic rods, like their metallic counterparts, come with their unique challenges and potential drawbacks:
- Increased Stress: Despite their non-metallic nature, plastic round bars can lead to heightened stress at contact regions due to point-loading. This concentrated stress has the potential to damage the structural integrity of both the pipes they are designed to protect and their structure.
- Friction & Paint Erosion: Pipe movement and vibration can generate significant friction between the pipe and plastic rod, despite the rods’ slick surface. This friction, coupled with the enormous stress caused by the pipe’s weight on a small surface area of the rod, leads to erosion of the pipe’s protective paint coating. This erosion exposes the pipe’s bare surface to corrosive agents, potentially exacerbating corrosion issues.
- Risk of Breakage & Detachment: Plastic rods may occasionally break off or detach from their locations, especially if manufactured from inexpensive materials or installed improperly. Such occurrences leave pipes vulnerable and unprotected. Failures are more prevalent when supporting large and heavy pipes, pipes experiencing extreme temperatures or temperature changes, or pipes undergoing significant movement or vibration. Despite being made from resilient material, the relatively small size of these rods and the necessity to drill bolt holes for most installations can weaken their structural resiliency.
Plastic Rod Failure
Comparison
| Plastic Rods | SmartPad System |
|---|---|
| Point-Loading Damages Pipe Structure & Paint Coating | Saddle Shape Protects Pipe Structure & Paint Coating |
| Installation Requires Experienced Craftsman | Lower Skilled Laborers Can Install with Minimal Training |
| Faulty Installs Possible | Minimal Chances of Installation Failure |
| Rods Can Fail or Break Off | Shape & Design Makes Them Structurally Resilient |
Wraps, Liners, and Sheets
The use of rubberlike materials, including Neoprene, HDPE, PTFE, and similar flat sheet materials, is a common method to isolate metallic pipes from supporting structures and the environment, preventing galvanic corrosion. However, this approach presents drawbacks and challenges:
- Slippage and Displacement: These sheets may slide off or become displaced over time, potentially exposing the metallic pipe to its metallic supporting structures.
- Tearing and Damage: High friction forces or other mechanical stresses can cause tearing or damage to these sheets, diminishing their effectiveness or rendering them useless in protecting pipes against external corrosion.
- Limited Durability: The thickness of these materials may result in limited durability, especially in challenging industrial environments. Frequent replacements may be necessary to maintain their effectiveness as protective barriers against metal-to-metal contact, which would significantly increase overall ownership costs.
Comparison
| Wraps, Liners, & Sheets | SmartPad System |
|---|---|
| Thin Sheets with No Airflow Improvement | The pipe crevice region is completely protected by a pad/gasket |
| Can Be Torn or Shredded | Made From Resilient FRP that will Last 30 Years or More |
| Can Fall or Break Off | Strapping System Ensures Pads Stay on Pipes During Lifecycle |
Epoxied-On FRP Wear Pads
Exploring the strengths and weaknesses of epoxied-on FRP wear pads, which bear a strong resemblance to the RedLineIPS SmartPads, provides valuable insights into this specific corrosion protection solution. Epoxied-on or glued-on FRP wear pads have proven effective in addressing Corrosion Under Pipe Supports (CUPS). Here’s a brief examination of their strengths:
- Effective Separation and Support: FRP pads excel at efficiently separating and supporting the contact region of a pipe, preventing direct metal-to-metal contact that can lead to galvanic corrosion.
- No Point Loading: Their saddle-shaped structure eliminates point loading, ensuring even distribution of stress on the pipe. This prevents structural damage over time and protects the pipe’s protective paint coating, which prevents corrosion from forming.
- Simplified Installation: They neither require welding or welding permits nor do they necessitate line shutdowns, simplifying the installation process.
Drawbacks of Epoxied-On FRP Wear Pads
While FRP epoxied-on wear pads are a recognized solution for Corrosion Under Pipe Supports (CUPS), they come with certain drawbacks, particularly when compared to the RedLineIPS SmartPad System, as follows:
- Installation Time: The installation process can be time-consuming, taking an hour or more for each pad.
- Installer Skill Dependency: Achieving a successful installation requires a high level of installer skill, making the process costlier and also sensitive to errors.
- Dependency on Epoxy: The use of epoxy to fasten the FRP wear pad to the pipe introduces several challenges
- Applying epoxy demands skill, patience, and precision, with the risk of over-application or under-application being significant.
- Epoxy application is challenging in hot weather and nearly impossible in regions with very low temperatures.
- Epoxy application necessitates paint touch-up after installation, adding to the overall expense.
- Cure time of 24 hours requires a return visit to remove zip ties, with even more additional costs if man-lifts are needed for access.
- Surface Roughening: The installation process requires roughening the pipe’s surface for proper epoxy adhesion, compromising the pipe’s protective paint coating.
- Limitation on Uneven Surfaces: These pads cannot be used on existing pipes with uneven surfaces, potentially caused by previous corrosion treatment. The epoxy requires an even surface for proper adhesion of the epoxy to the pipe.
To learn more about FRP Wear Pads –
FRP Wear Pad Failure
Comparison
| FRP Wear Pads | SmartPad System |
|---|---|
| 30-60 Minute Installation Time | 2-4 Minute Installation Time |
| Requires Additional 24 Hour Cure Time | No Cure Time |
| Epoxy is Messy in Summer & Not Usable in Harsh Winters | No Use of Epoxy |
| Requires Perimeter Bead to Seal Pad to Pipe | One Step Installation |
| Requires Paint Touch-Up After Installation | No Paint Touch-Up Needed |
| Not Suitable for Pipes Previously Treated for Corrosion | Suitable for New, Existing, & Treated Pipes |
| Faulty Installs Possible | Minimal Chances of Installation Failure |
| Installer Experience is Critical | Lower Skilled Laborers Can Install with Minimal Training |
RedLineIPS SmartPad System vs. Alternative Solutions
| Metallic Wear Pads | Metal Round Bar | Plastic Round Bar | Rubber/Plastic Liners | Epoxied-On FRP Wear Pads | SmartPad System | |
|---|---|---|---|---|---|---|
| Eliminates Crevice Corrosion? | Yes | Yes | Yes | Yes* | Yes | Yes |
| Eliminates Galvanic Corrosion? | No | No | Yes | Yes* | Yes | Yes |
| Prevents Metal-to-Metal Contact? | No | No | Yes | Yes* | Yes | Yes |
| Saddle Shape Cradles Pipe to Alleviate Stress? | Yes | No | No | No | Yes | Yes |
| Eliminates Point-Loaded Stress? | Yes | No | No | Yes | Yes | Yes |
| Strong Structural Resilency? | Yes | Yes | No | No | Yes | Yes |
| Works with Pipes Previously Treated for Corrosion? | Yes | Yes | Yes | Yes | No | Yes |
| Minimal Installation Training Needed? | No | No | Yes | No | No | Yes |
| Minimal Possibility of Faulty Installation? | No | No | No | No | No | Yes |
| Welding or Welding Permits Not Required? | No | No | Yes | Yes | Yes | Yes |
| Epoxy Not Required? | Yes | Yes | Yes | Yes | No | Yes |
| Eliminates Line Shutdown Requirement? | No | No | Yes | Yes | Yes | Yes |
| Eliminates Need for Paint Touchup? | No | No | No | No | Yes | Yes |
| Minimal Corrosion Inspection Cost? | No | Yes | Yes | No | No | Yes |
| Average Installation Time? (Minutes) | 60 | 30 | 5 | 5 | 15 | 2 |
| * Yes, for a limited time, until torn or shifts out of position | ||||||
SmartPad System vs. FRP Wear Pad Installation Comparison
To witness a side-by-side installation comparison between our SmartPad System and epoxied-on FRP wear pads, please refer to the video. The test demonstrated that installing a SmartPad took less than two (2) minutes compared to the twelve (12) minutes required for an epoxied-on wear pad, even when conducted on a brand new pipe by an experienced installer. On average, contractors typically bill clients an average of 1 to 1 ½ hours per FRP wear pad installation, accounting for surface preparation and paint touch-ups.
View the SmartPad System’s operational advantages –