Chilled Water Pipe Vibration Isolators
Chilled Water Pipe Vibration Isolators - Vibration isolators protect the chilled water piping from receiving vibrations transmitted through the piping when the chillers are running. The vibrations can create problems not only for the chilled water piping but also for the building’s structure. The vibration isolators reduce or eliminate the vibrations that can be transmitted by the chillers.

Chilled Water Pipe Vibration Isolators

Other equipment normally specified with vibration isolators includes air handlers, pumps, condensing units, generators, and most types of equipment with motors. Not only are vibration isolators required in the piping but vibration elimination springs or spring isolators are required on chillers, pumps, air handlers, and the other types of equipment named above which can produce vibrations when running.

Vibration isolators are usually rated according to the static deflection the vibration isolator provides for the equipment. HVAC piping whether it is for hot water or chilled water usually is also specified with springs in the pipe hangers to avoid further issues that can be caused by vibration. Depending on the location vibration isolators will also be rated for seismic activity with further specifications calling for seismic restraints on the equipment and associated piping.

Parts of the Chilled Water Pipe Vibration Isolators

Chilled Water Pipe Vibration Isolators - The materials that make up the vibration isolators in the photo include the stainless mesh, rubber hose assembly properly rated to exceed the design pressure of the water loop, and flanges and bolts that hold it all together. Properly assembled the chilled water pipe vibration isolators will prevent many serious problems in the future. Other types of equipment and components that require vibration isolation include ductwork will also have rubber or a special material to isolate vibrations from the air handler or fan coil unit through the ductwork and into the structure.

Refrigerant Lines – Chilled Water Pipe Vibration Isolators

Refrigerant piping lines require vibration isolators along with an electrical conduit. Basically, any type of mechanical or electrical equipment that can and will produce vibration will be specified for vibration isolators to prevent vibration from being transmitted through the pipe, ductwork electrical conduit and refrigeration lines and into the structure.

Why Vibration Isolators? Chilled Water Pipe Vibration Isolators

One may ask why vibration isolators are required for piping systems and other things including electrical conduit connections and ductwork? The simple answer is that pipe vibration eliminators are generally required by code but other than seismic reasons listed above it is because HVAC equipment including pumps, chillers, and other types of HVAC equipment will vibrate. These vibrations can be transmitted through the piping system and to other parts of the building.

Over time this slight vibration can cause anchors (such as the anchors used for pipe hangers) to loosen and fall out. In essence, the system will begin to fall apart and it will be a serious safety hazard in the future if not addressed upon initial installation. Refrigerant leaks, water leaks, and nuisance noises can be avoided with vibration isolators.

Problems without Vibration Isolators – Chilled Water Pipe Vibration Isolators

Other problems that can develop in the future if vibrations are not addressed include micro-cracks forming in metal including the piping of the system and this can lead to catastrophic failure of the entire system. Always ensure your system has the proper vibration isolators in it whether it is a chilled water pipe, hot water pipe, or any other type of pipe attached to a device that can and will vibrate even if the vibration is slight.

Troubleshooting Problems – Chilled Water Pipe Vibration Isolators

Finally, several years ago I was called to a job by a customer of a large multi-story building. The customer explicitly trusted me and my skills. He had a tenant in one of the premium office spaces that was complaining about an intermittent noise she kept hearing.

This particular tenant happened to be one of the partners in a law firm that paid handsomely to have the premium office space so it was important to my customer that his customer was happy. He wanted me to investigate the noise. He suspected the noise was coming from the HVAC system but wasn’t sure and wanted an expert opinion.

Bread Crumbs

Boiler Vibration Isolators | HVAC Piping

Pulse Boilers require vibration eliminators or isolators installed on the piping near the boiler.

I began at the source and opened the drop ceiling in her office. I noticed several pipes that were labeled so I had something to go by (thanks to other code requirements about labeling piping). I also saw a VAV box there with pneumatic controls. I checked out the VAV box and all the pneumatic controls including the pneumatic tubing which will make a noise if it has a leak. I came up with nothing.

I followed the piping out. Everything seemed okay with the chilled water piping. When I came to the hot water piping and tracing it out I found a problem. It seems one of the boilers had been replaced six months before. The boilers in place were pulse boilers and pulse boilers need vibration isolators in the piping as pulse boilers will cause vibration and transmit the vibration through the piping.

I shut all the boilers down except the boiler that had been replaced and gave it a call for heating through the building automation system. I went back to the office and found the problem. The boiler was transmitting the vibration through the pipe and the pipe hanger was vibrating ever so slightly against another hanger. A touch with my finger would stop the vibration and the noise.

Problem Solved

The problem was difficult to track down because it was intermittent and only occurred when that particular boiler fired. There were six boilers in the mechanical room three stories below the office and they were in lead-lag operation. The customer called the mechanical company that had installed the new pulse boiler and had them fix the issue by installing a vibration eliminator in the piping serving that boiler. My customer was happy, his tenant was happy, and I put another notch in my belt for a mystery solved. Vibration isolators can solve many issues so make sure your system is equipped properly with vibration eliminators.

Related Link: Learn more about Piping Design and Best Practices for Refrigeration Piping (opens in a new window)


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Chilled Water Pipe Vibration Isolators