Being Wisconsin in January, you can imagine how cold it gets for both people and machines. Nothing says, “cold” like starting a car with frozen seats, frozen brakes, and frozen gear shift. Cars aren’t the only pieces of equipment that are affected by cold: pumps deal with cold air and ice.
Carl Brennand, writing at the Gibbons Group blog, provides some guidelines to avoid damage to your pumps this winter.
There’s a chill in the air and frosty mornings are becoming more frequent as autumn gives way to winter, which means it’s time to start protecting your electro-mechanical equipment to see it through the cold months. Pumps are no exception, and here we highlight a couple of the most common threats to pumps during winter.
When a cold pump is activated, the fluid being moved may be warmer than the components of the pump. If this is the case, thermal shock can occur and cause parts such as the impeller, shell and suction liner to crack. Thermal shock can be avoided by bringing the pump components up to temperature gradually with external heat. However, don’t use a blowtorch or other open-flamed device as these represent a fire risk. Use a portable heater instead.
After a pump is shut down, some liquid may remain in the bottom, which in sub-zero conditions will freeze and expand. Components and casings will fracture under the pressure, but the problem won’t become apparent until the ice thaws and your pump leaks when started up. When shut down, pumps should be drained off via the drain valve which can be found at the lowest point. If your pump is not fitted with a drain valve, consider having one installed so you can be certain the equipment is completely empty of fluid when not in use.
Large AC motors are affected by the extreme cold, too. In a post written here last January, Baldor Motors shared some ways to help your motors deal with cold:
For an ambient below 40 ºC [104 ºF] , design and selection criteria focus primarily on materials and lubrication. Typically, no modifications are required for an ambient down to approximately -20 ºC [-4 ºF] . For ambient temperatures below that, however, the first consideration is lubrication. For grease-lubricated bearings, make certain the grease is suitable for the ambient and is compatible with the manufacturer’s recommendations. Oil-lubricated bearings in low-ambient conditions will require a thermostatically controlled oil sump heater to maintain the oil at an acceptable temperature.
When ambient temperatures fall below -25 ºC [-13 ºF] , additional consideration must be given to the types of materials used in manufacturing. The most common material changes will be in fans, shafts, frames and end brackets. Fans may need to be changed from plastic to either steel or bronze. Shaft material will likely be changed from a standard material, such as AISI 1040, to a high-strength alloy like AISI 4140. Cast-iron frames and end brackets will typically be changed from grey iron to ductile iron due to the brittle nature of grey iron in low-ambient conditions.
These material changes will need to be made at various ambient ranges between -25 ºC and -60 ºC [-13 ºF and -60 ºF] , depending upon the standard material and application. In addition to low ambient, the harsh environments of resource industries require other considerations. Conditions common to harsh environments include outdoor installations, corrosive or salt-laden atmospheres and exposure to abrasive materials. In these scenarios, consideration must be given to the proper motor enclosure and bearing protection.
Cold weather also affects predictive maintenance tasks. As we concluded in a post from December, it’s an important strategy to know the health of your equipment before something bad happens.
Overall, predictive maintenance must be implemented all year round, considering how important it is in ensuring proper business operations and productivity. In winter, most specifically, the intense cold climate can contribute to machine failure and electrical problems. By applying constant maintenance approach on electric motors and equipment, this can significantly minimize the amount of equipment that require premature replacement or repair due to electrical concerns.
Most importantly, predictive maintenance is necessary to ensure safety in the workplace at all times. After all, prevention of injuries, accidents or death in the company is worth every dollar you allot for regular maintenance of equipment. When everything in the company is running smoothly, you can protect your assets, continue growing your business, and reap maximum profits over time.
Common sense is a recurring theme throughout this post. Being consistent and thorough with the care your rotating equipment doesn’t guarantee against failure. Nothing does. But, it will put some pretty good odds on your side.