Gallagher recently released its Expansion Joint Design Guide, now available for download on our site. This design guide takes an in-depth look at elastomeric, metal, and flue duct expansion joints. The excerpt below is a section of our Expansion Joint Design Guide focusing on types of elastomeric joints and types of pipe movement. To download the entire guide, visit our Resources Page, or click on the image to the right.
The basic purpose of an expansion joint is to absorb movement and vibration in a rigid piping system, being built to expand, contract, and adjust without straining or breaking the piping or ducting on either side. They are specially engineered to handle movements due to thermal expansion, vibrations of pumps, and misalignments due to installation tolerances, while also being resistant to the process conditions and the external influences of the application.
Air Sentry® breathers should be an integral part of any proactive maintenance and reliability program. The breathers are designed to replace the breather cap or air filter on gear boxes, hydraulic fluid reservoirs, bulk storage tanks, oil drums, oil-filled transformers, and other fluid reservoirs. Most older style air venting methods provide minimal, if any, contamination control. Air Sentry® breathers provide the first line of defense in contamination control methodology, utilizing patented designs and featuring color indication silica gel and self-cleaning 2-micron filtration.
There are two important threats to productivity that an Air Sentry breather can protect you from:
Particulates
One research group found that greater than 75% of all machine wear related failures were due to particulate contaminants. Frequently the greatest cost of equipment failure is not the component replacement cost, but the labor production downtime. Most particles start off as dirt that becomes airborne, finds its way into lubricant and fuel reservoirs, and is later transported to bearings, bushings, seals, valves, and other machine components. There they become key ingredients in abrasion, erosion, and fatigue failures. The contaminants also cause lubricant degradation, shortening the life of the lubricant and decreasing its ability to lubricate.
Thordon non-metallic bearings have been used in a wide range of industries and various applications such as in pumps, pivot points, screw conveyors, hydro turbine wicket gates, agitators, and flocculator paddle wheels. Thordon Bearings are design to work under the most extreme conditions: abrasive, corrosive, high impact load, high humidity, and infrequent maintenance periods.
With a low inherent coefficient of friction, Thordon bearings typically do not require grease lubrication. This results in reduced maintenance costs and safety issues. Environmental and product contamination concerns associated with grease lubrication are eliminated. Thordon Bearings are homogenous polymers with built-in lubricants. The lubricants, being dispersed through the bearing material, continue to provide low friction through the life of the bearings.
The face seal design chart below explains the hardware dimensions to use for an O-ring seal when the groove is cut into a flat surface.
For designing systems which contain internal pressure, like the example below, the groove's outside diameter (OD) is primary, and the groove's width then determines the inside diameter.