Let's know the operation and characteristics of slotted mechanical pipe systems for air conditioning.
By Luis Henao*
If you do not know the slotted systems of mechanical joining of pipes, it is likely that you do not know the positive benefits that can result in your final result. The method of joining by grooved pipes has been changing the way the contractor does business over the course of more than 95 years, however, this method of joining pipes is still not fully known, or is misunderstood in certain sectors of the commercial construction segment. Look at any of the fire protection systems in commercial buildings and you will realize that slotted systems are the preferred joining method, but look at HVAC systems, and you will often find alternate methods of joining.
For those HVAC systems that employ alternating methods of joining, there is an opportunity to save time and potentially increase profitability by using slotted mechanical systems where possible. Contractors using slotted mechanical systems are able to complete new projects or refurbishment work more quickly, while helping to maintain worker safety and contributing to the building's overall sustainability goals. The multiple benefits that are obtained through the use of slotted pipes can easily become a competitive advantage, an advantage absolutely worthy of the attention of a contractor.
Introduction to slotted pipes
The pipe joining method is an important factor when designing and installing a system. Before choosing the joining method, it is important to take into account several factors, including installation conditions, project schedule, available job skills, and tool requirements, as well as take into account other design and construction considerations.
Each of these elements impacts on which pipe method is the most suitable. The main methods of joining carbon steel and stainless steel pipes in the commercial HVAC market are welding, flange, threading and, of course, grooving. As each project has its own particular set of challenges, it is necessary that each one takes into account the best possible solution for that application. In the case of HVAC systems, the opportunities to use slotted systems are numerous, but the concept/methodology and the benefits they can provide are not as widely known.
A slotted pipe joint is made up of four elements: the slotted pipe, the packing, the coupling segments, and the nuts and bolts. Slotted pipe joints can employ one of two basic coupling styles: flexible or rigid. Flexible couplings allow for a limited amount of angular and longitudinal movement, while rigid ones have angled bolt closures that produce a rigid joint and allow no movement between the ends of the tubes. There are benefits to both rigid and flexible styles: rigid couplings can be used where immobility is necessary at the pipe joint, similar to a flanged or welded joint.
Flexible couplings are capable of handling thermal expansion and contraction of the pipe, differential settlement between structures, attenuate vibrations in the pipe and accommodate seismic movement, and as such, are ideal wherever movement is likely, such as joints around equipment connections, changes in direction, and building expansion/seismic joints.
Shrinking construction programs
Nowadays, the schedules and times in construction projects are increasingly tight, which is why the management of the same and the fulfillment of critical dates are not only a priority, but also critical elements directly related to the success and profitability of the project. The ease and speed with which slotted mechanical piping systems are installed is how the contractor obtains a positive impact on the final result of the project and thus obtains a competitive advantage.
Slotted pipe joints are easy to assemble. They do not need flame, heat, or specialized tools, and some manufacturers provide slotted couplings that have no torque requirements. Standard slotted couplings can be up to five times faster to assemble than welded joints and up to three times faster than flanged joints.
Although the initial cost of the materials of a slotted mechanical pipe system may be higher than other methods of joining pipes, slotted systems serve to decrease the total cost of installation because they reduce the working time, which turns out to be the main variable cost in the field.
Greater safety in the works
The slotted pipe is not only easy and quick to install, but also, it is much safer than any other method of joining. Slotted mechanical piping systems are installed without the need for flame, and this eliminates fire hazards typically associated with welding. Welding is one of the most dangerous industrial activities, in the sense that they are dangerous because of the risk of fires, electric shocks, compressed gases and toxic fumes.
It is for this reason that when welding, it is necessary to have personal protection for the eyes, hands, feet and body. Welding activities also require fire surveillance during and after work, which can delay the construction schedule and increase costs.
The safety of installers on construction sites is always of the utmost importance; however, it becomes an even more critical aspect in expansion and/or refurbishment projects where there are buildings such as hospitals or schools that can remain open and in operation during the construction stage. Slotted mechanical pipes can reduce risks to workers, as in the case of refurbishment or expansion projects, and building tenants.
Truly sustainable projects
Slotted joining technology is based on sustainability; its inherent qualities make it by nature, respectful of the environment. Slotted mechanical piping systems significantly reduce or eliminate waste, emissions and noise pollution in the workplace, and this in turn leads to a much safer and healthier environment.
A slotted mechanical pipe joint does not require the use of electricity during installation, which reduces the consumption of energy resources. Welding pipes demand large amounts of electricity for extended periods of time. In addition, the quality of the indoor and outdoor air is preserved because there are no fumes or particles that endanger the worker or the environment. By eliminating these harmful emissions, air pollution is reduced, thereby achieving a more sustainable and safe environment during construction, maintenance or expansion.
The air conditioning system, one of the main energy consumers within a building, requires regular maintenance to ensure the efficient operation of the building. The sustainable nature of slotted mechanical piping systems can help reduce the environmental impact of structures, as well as increase efficiency over the life of the building.
Mechanical pipe joining systems offer an optimal way to effectively maintain piping systems in structures, and this reduces maintenance deferral, promotes operational efficiency and saves money.
Each slotted joint is an access point to the system, enabling quick and easy routine maintenance, system expansion and subsequent refurbishments. To enter a system in a slotted joint, it is enough for the worker to loosen two nuts and bolts and remove the segments and packing. An embryonated joint, with its multiple bolts, is tedious and takes longer to disassemble and reassemble compared to a slotted joint.
Finally, flexible couplings reduce noise and vibrations transmitted into the pipe from pumps, chillers and other equipment. This attenuation of vibration is achieved because the elastomeric packing passes through the ends of the pipe, being in contact with the coupling segment, the wedges of the segments float in the grooves, the ends of the pipe are separated, and the ductile iron housing runs with a higher damping coefficient. The use of flexible couplings around equipment connections can eliminate the need for vibration attenuation devices such as rubber bellows and braided flexible connectors.
Conclusion
Many mechanical contractors have switched to slotted mechanical pipes when appropriate for the ease and speed of installation, apart from the fact that they are much safer for the worker and people in the vicinity, and provide longer-lasting sustainable benefits, all aspects that can positively impact the final result of the contractor.
* Luis Henao is Victaulic's regional manager for Central America, the Caribbean and Northern South America.
