Conventional welded piping involves several fabrication and inspection stages, including joint preparation, fit-up, tack welding, welding, visual inspection and dye penetrant testing. These activities can increase fabrication time, labour requirements and the overall duration of piping installation.Pyplok® is a mechanical pipe connection system that uses a hydraulically powered tool to radially swage a fitting onto the pipe. The connection is formed without welding or heat generation, offering potential advantages in installation speed, workplace safety and access to confined or restricted areas.
A comparative study conducted by ALUSA Engineering assessed Pyplok® against conventional welded piping using two lines with identical materials, diameters, joint counts and spool geometries. Both spools were prepared and assembled under the same conditions by the same team to minimise the influence of human factors and support a fair comparison.
In the study:
| Conventional Welding | Pyplok® | |
|---|---|---|
|
No of Joints |
12 |
12 |
|
Total execution time |
231 min |
98 min |
|
Average time per joint |
19.25 min |
8.2 min |
|
Total Fabrication Cost |
R$ 10,217.28 |
R$ 4,284.72 |
the reported execution time was therefore approximately 59% lower for Pyplok® in this particular test, while the reported fabrication cost was approximately 58% lower.
What is Pyplok®?
Pyplok® is a 360° radial-swaged mechanical fitting system designed to create permanent pipe and tube connections without welding. During installation, a hydraulically powered compression tool radially swages the fitting onto the pipe, forming a mechanically retained and sealed connection.The fitting incorporates O-ring sealing elements to provide sealing and environmental protection. According to the product description, an inner primary seal provides high-pressure sealing, while an outer environmental seal helps prevent fluids and contaminants from entering the interface between the fitting and the tube.Using a cold-work installation process, Pyplok® eliminates the heat generation associated with conventional welding. This makes it an alternative for industrial piping applications where non-welded connections can offer installation and operational advantages.
Key Characteristics
1. Non-welded connection – Creates a mechanical connection without welding.
2. Cold-work installation – No heat is generated during the joining process.
3. Hydraulically powered tool – Uses a dedicated tool to install the fitting.
4. 360° radial swaging – Applies radial compression around the fitting to form the connection.
5. Permanent mechanical joint – Designed to provide a lasting connection once installed.
6. O-ring sealing – Incorporates sealing elements for pressure sealing and environmental protection.
7. Industrial applications – Suitable for a range of industrial piping applications, subject to system requirements and product specifications.
8. Material options – Available in carbon steel, stainless steel, copper-nickel (Cu-Ni), Duplex and Super Duplex, depending on the specific product configuration.
Steps in Joining Pipes
| Conventional Welding Connection | Pyplok |
|---|---|
|
|
Design Conditions
| Parameter | Test Condition |
|---|---|
|
Application |
Boiler water for steam generation |
|
Design Temperature |
223° C |
|
Design Pressure |
15.1 kg/cm² (14.8 bar) |
|
Hydrostatic Test Pressure |
23.1 kg/cm² (31.5 bar) |
|
Insulation |
38mm |
|
Operating Temperature |
193° C |
|
Operating Pressure |
12.6 kg/cm² (12.4 bar) |
Installation Time Comparison
| Fabrication Activity | Welding | Pyplok® |
|---|---|---|
| Pipe preparation, cutting plan & connection cleaning | 75 min | 60 min |
| Pyplok® fitting compression | — | 38 min |
| Coupling using ER welding process | 105 min | — |
| Welding connections | 21 min | — |
| Visual inspection | 15 min | — |
| Dye penetrant inspection | 15 min | — |
| Dimensional inspection | Equal | Equal |
| Hydrostatic testing | Equal | Equal |
| Total execution time | 231 min | 98 min |
| Number of joints | 12 | 12 |
| Average time/joint | 19.25 min | 8.2 min |
The study reported 231 minutes for conventional welding compared with 98 minutes for Pyplok®, resulting in a reduction of approximately 133 minutes for the 12-joint spool.What this means
For the particular test:
Welding: 19.25 minutes/joint
Pyplok®: 8.2 minutes/joint
That represents approximately 2.35× faster execution per joint in the test.
Fabrication Cost Comparison
| Fabrication Phase | Welding Cost (R$) | Pyplok® Cost (R$) |
|---|---|---|
| Pipe preparation, cutting plan & cleaning | 2,751.00 | 2,200.80 |
| Pyplok® compression | — | 1,393.84 |
| Pyplok® operator | — | 690.08 |
| Coupling using ER welding | 3,851.40 | — |
| Welder – coupling | 2,339.40 | — |
| Welding connections | 467.88 | — |
| Visual inspection | 403.8 | — |
| Dye penetrant inspection | 403.8 | — |
| Total | 10,217.28 | 4,284.72 |
Reported Result
| Metric | Result |
|---|---|
| Welding fabrication cost | R$10,217.28 |
| Pyplok® fabrication cost | R$4,284.72 |
| Difference | R$5,932.56 |
| Approx. reduction | 58.10% |
The study reported a total fabrication cost of R $10,217.28 for the welded system compared with R$ 4,284.72 for Pyplok®.
Manpower and Process Requirements
| Welding requires | Pyplok requires |
|---|---|
|
|
The study therefore identifies the elimination of welding and weld inspection stages as one of the significant contributors to the reduction in execution time and cost
Testing and Leak Performance
The ALUSA test lines were subjected to a hydrostatic test at 23.1 kg/cm² (31.5 bar) without leaks. A separate bench test using the same material as the spool was performed at 250 kg/cm², with no leaks reported. A pneumatic test was also performed on the Pyplok® spool, with no leaks detected.
Key Advantages Identified in the Study
No Hot Work
Pyplok® is installed using a cold compression process and does not generate welding heat during installation. The source document specifically identifies this as advantageous in flammable environments such as refineries.
Faster Installation
The ALUSA comparison recorded 98 minutes vs 231 minutes for 12 joints.
Reduced fabrication activities
Welding, visual weld inspection and dye penetrant inspection were eliminated from the Pyplok® process examined in the study.
Lower reported fabrication cost
The ALUSA study recorded a fabrication cost of R$ 4,284.72 vs R$ 10,217.28.
Reduced shutdown time potential
The document identifies rapid installation as a means of reducing shutdown duration.
Portable installation equipment
The study identifies portability of the equipment as an advantage.
Where Pyplok® Can Provide Value
The document identifies applications across industries including: Marine & Offshore Navy Oil & Gas Petrochemical Steel Mining Industrial applicationsIt also describes applications involving gases, oil, compressed air and steam, subject to the applicable system limitations and specifications.
Conclusion
The comparative study conducted by ALUSA Engineering highlights the potential of Pyplok® to reduce fabrication time and costs for small-diameter piping connections compared with conventional welding.
For the 12-joint spool evaluated, the results were as follows:
Fabrication time: Reduced from 231 minutes to 98 minutes.
Fabrication cost: Reduced from R$10,217 to R$4,285.Under the specific test conditions, the study demonstrated approximately 59% less fabrication time and 58% lower fabrication costs using Pyplok®.
Beyond these time and cost savings, Pyplok®'s cold-work installation process eliminates welding heat and removes several welding-related steps from the fabrication sequence.
These advantages may be particularly valuable in applications where hot-work restrictions, shutdown duration, limited access or faster installation are key considerations.
Pyplok® is more than an alternative pipe fitting; it offers a different approach to joining piping systems, with the potential to simplify fabrication, streamline installation and facilitate future maintenance.
