In addition to increased safety, Pyplok® weldless installations offer substantial cost savings over traditional welding methods. Pyplok® systems have been tested rigorously across all industries for which they have been employed, and time and time again it has shown to be superior to welded systems in durability and time and costs saved.
Pyplok® is a 360° radial swage mechanically attached fitting which connects pipe and tube for a leak free, cold connection. The system is fast, reliable, permanent and tamperproof. It’s ideal for use in new build and maintenance work where fire hazards exist, and a clean piping connection is required. Learn more about Pyplok® here.
Pyplok® recently conducted a test at an Alusa/Petrobras site in Comperj across two identical steam lines to compare conventional hot processes to its mechanical cold compression system.
Both lines underwent the same preparation, assembly, and hydrostatic testing, and were subject to identical conditions, to ensure consistent results.
We selected two lines from the project of the same material, diameter, number of joints, and geometry of the spool to compare both processes. Pipe preparation, coupling, and assembly of the two spools were made in the same conditions, at a work bench, by the same team, to avoid any influence in results due to the human factor. The two lines were accompanied by a dimensional inspector and were subjected to hydrostatic tests according to project specifications.
In a conventional welding process, fittings require positioning, tacking, and then welding. Post welding die penetration inspections must be performed prior to hydrostatic testing. The Pyplok® cold compression process uses a swaging tool to compress fittings, eliminating the need for welding and die penetration inspection. Pyplok® saves your operation all costs associated with qualified welders, hot work permits, fire watch, flushing and purging, gas freeing, and radiography.
Overall, the line installed using the Pyplok® weldless cold swaging system was completed using far fewer man-hours and incurring far fewer extra costs. The system performed just as well as the line installed via traditional welding but was up and running in a fraction of the time and of the budget.
| Phase | Time (in min) using manual hot welding process | Time (in min) using Pyplok® cold compression process |
| Preparation of pipe, including cutting plan and connection cleaning (resource: 2 pipe fitters) | 75 | 60 |
| Spool coupling with Pyplok® machine (resource: 2 pipe fitters; 1 operator) | N/A | 38 |
| Connection coupling using hot welding process (resource: 1 pipe fitter; 2 welders) | 105 | N/A |
| Welding connections (resource: 1 welder) | 21 | N/A |
| Visual inspection (resource: 1 end inspector) | 15 | N/A |
| Die penetration inspection (resource: 1 end inspector) | 15 | N/A |
| Dimensional inspection (resource: 1 dimensional inspector) | = | = |
| Hydrostatic testing | = | = |
| Total number of joints | 12 | 12 |
| Total time | 231 | 98 |
| Average time per joint | 19.25 | 8.2 |
The times for dimensional inspection and hydrostatic testing are the same in both cases and are not considered in the execution time for the spool.
The lines were subjected to hydrostatic testing to 23.1 kg/cm2 (31.5 Bar) without leaks. A bench test was performed on a test piece, using the same spool material, having a fitting compressed over two nipples. Pressure tested to 250 kg/cm2 with no leaks.
A pneumatic test was performed on the spool assembled using Pyplok® system and no leaks were detected in 1″-AV-2400-442-Ce-IQ.
The result of this case study was that the Pyplok® system proved to be a more cost-effective solution than traditional hot work system for on-site pipework fabrication and repairs.
Mechanically attached systems using Pyplok® fittings are ideal for joining small diameter pipes, usually between ¼″ and 4″, made of carbon steel, stainless steel, duplex, super duplex, copper nickel, titanium, and other nonferrous metals. Pyplok® fittings can be used on high-pressure applications such as hydraulic, gas, oil, compressed air, and steam limited to 205° C. This cold compression work process is invaluable for applications where hot work, or welding, is too expensive, too dangerous, or otherwise logistically impossible, such as in classified areas.
