As plants continue to consolidate and streamline operations in the search for greater efficiency, one unintended consequence is that installation and troubleshooting knowledge can be lost as maintenance personnel retire or relocate to new jobs.

In most plants and mills around the world, maintenance personnel are typically responsible for installing and troubleshooting compression packing, a reliable and economical means of controlling leakage in pumps and other mechanical equipment. This article serves as a guide describing the best way to troubleshoot and solve common compression packing problems in order to improve the performance of the packing and prolong the life of the equipment that it seals. 

Pumps & Systems, July 2007

Conclusion of our series covering applications in which they are used, why they are used, how they fail and things operators can check/do to maintain the performance of the seal flush plan.

Plan 52

Plan 52 uses an external reservoir to provide buffer fluid for the outer seal of an unpressurized dual seal arrangement. During normal operation, circulation is maintained by an internal pumping ring. The reservoir is usually continuously vented to a vapor recovery system and is maintained at a pressure that is usually at or near atmospheric pressure. The inner process seal of the dual unpressurized arrangement usually has its own flush plan.

Pumps & Systems, May 2007

This discussion opens a three-part series covering mechanical seal piping plans that provide guidelines for various seal arrangements, fluids and control equipment to help you determine what support system requirements will maximize the performance reliability of your application.

FSA Sealing Sense

Pumps & Systems, May 2007

Manufacturers of braided packings are often asked to simply supply "A PTFE packing." Though this may seem a straightforward request, it generates questions that must be answered to ensure the correct PTFE packing for the application. A clear understanding of the differences between the various forms of PTFE braided packing will enable a selection of reliable sealing for the pump or valve. 

Pumps & Systems, May 2008

Bolted flange gasket technology continually evolves with new designs and materials that provide more reliable and durable seals. Plant operators can choose from a wide variety of gasket products that meet the needs of each application; however, selecting the optimal gasket product is only half the battle. 

Pumps & Systems, May 2008

Most shaft seals are typically placed in bores made of steel, cast iron or other common ferrous metallic material. These ferrous, or iron-containing materials, are compatible with both metal cased and rubber covered seals. Alternatively, bores made of non-ferrous materials or softer alloys like aluminum require special consideration, especially when subjected to temperature extremes. For instance, when a shaft seal with a carbon steel case is fitted to a bore made of aluminum and exposed to high temperatures, the result is a loose fit and seal failure because of the differential rates of thermal expansion between the steel cased seal and the aluminum housing.

Pumps & Systems, May 2008

Maintaining equipment uptime in a mining operation is essential. For one of South American's largest sulfurated copper mining organizations, unreliability simply wasn't acceptable, so they turned to one seal manufacturer to develop a pump sealing system improvement program using the Six Sigma methodology.

Pumps & Systems, May 2008

In principle, a successful sealing program is centered on tracking performance levels to ensure the reliability of shaft sealing components in process systems. This article focuses on the pumping asset only, less the other capital equipment also considered to make-up a "system." The ultimate goal of a sealing program is reducing the total cost of ownership of the asset for which the seal is installed. The focus should be a "pumping system" approach and include root cause failure awareness.

Pumps & Systems, May 2008

For more than 100 years, machine parts composed of mechanical carbon have provided an alternative solution in applications where temperature and atmosphere prevent the use of oil-grease lubricants. Mechanical carbon materials contain graphite, which is relied on for its self-lubricating characteristics. 

Mechanical carbon materials can be an effective solution-and sometimes the only workable solution-for moving/movable machine parts where rubbing must occur with low wear and low friction, and oil-grease lubrication cannot be used.

Pumps & Systems, May 2008

The purpose of a mechanical seal is to prevent leakage but all seals leak to some controlled degree. However, it is important to note that this minimal leakage can be so restricted that specific designs are capable of adequately meeting all emission requirements. Seal failure is defined as excessive leakage. The seal can be described as a controlled leakage device represented by two nonporous, plane, parallel walls separated by a distance h, the seal face separation. Assuming constant physical properties and laminar, incompressible flow, the leakage rate is proportional to the pressure and to the cube of the face separation.