Victaulic, specialises in mechanical pipe joining and flow control solutions and their products have allowed engineers to benefit from simplified construction structures without negating safety and quality standards.
“Victaulic products are tested to accommodate not only seismic, but thermal movement as well,” states Marcel Ley, regional manager, Victaulic South Africa. “This testing allows for system durability in practically all conditions, ensuring that engineers truly see the benefits of making use of our industry-leading products.”
Accommodating seismic movement
The main approach to designing a piping system that accommodates seismic activity is to an engineered combination of both rigid couplings and flexible couplings in key areas of the system to accommodate movement and sway. According to Ley, typically more than 95% of the grooved couplings used in a piping system will be rigid, while the remainder will be flexible couplings.
“The importance of this lies in the fact that too much swing could affect other pipes and equipment, despite being within the capability of the grooved coupling. The key to effectively accommodating movement in a building is to allow controlled movement and that can be done with flexible grooved technology.”
Ley further explains that two basic grooved coupling styles can be found. These include flexible grooved couplings which allow for a restrained amount of angular and axial movement; and the other being rigid grooved couplings which do not allow for movement and can be used in instances where immobility in the pipe joint is needed and can be described as similar to that of a flanged or welded joint.
To test the superiority of Victaulic flexible couplings in accommodating seismic movements, the couplings were tested at the ATLSS centre, a member of the nationally recognised NEES (Network for Earthquake Engineering Simulations) testing group. Victaulic couplings ranging in size from 4″ to 16″ (100mm to 400mm) were exposed to accelerations up to 50% greater than the Northridge, California earthquake which measured a staggering 6.7Mw magnitude.
The water-filled assemblies were pressurised to 200psi/1375kPa for the duration of each test; no pressure loss or leakage was noted.
“The technology is most notably in use at the Burj Khailfa in Dubai. As the tallest building in the world, the structure required an innovative, flexible solution to accommodate structural shrinkage as well as movement and sway due to wind load,” explains Ley.
“As such, Victaulic Flexible Couplings were used to absorb system movements from building settlement and wind sway; while Victaulic Style 155 Expansion Joints used as flexible connectors, were installed at strategic locations on potable water and wet risers.”
Accommodating thermal movement
“Some of the most damaging affects to a piping system can be the result of not accommodating for movement,” comments Ley. “Temperature changes can exert dangerous and damaging reactive forces on pipe components and equipment.”
There are however measures to accommodate pipe movement in instances of thermal change; with the company having identified key advantages in making use of its innovative products. These include pipe design flexibility; a reduction in pipe system stress; a more compact and productive method of installation as opposed to welding; and finally, the conformity to industry practises.