Gland packing plays a vital role in maintaining the integrity of mechanical systems by providing a robust and durable seal around shafts and valve stems. The importance of this humble yet integral component lies in its ability to prevent fluid leakage. Leaks can lead to significant energy losses, costly downtime, and potential environmental hazards. By effectively sealing gaps, this unsung hero helps maintain optimal pressure levels within systems, ensuring they run smoothly and reliably.
What Is Gland Packing?
Gland packing, also known as packing or compression packing, is a critical sealing device utilised in mechanical applications to prevent fluid leakage, particularly in pumps and valves. It accomplishes this by filling the space between the shaft and the housing, exerting sufficient pressure to form a tight, reliable seal preventing the escape of liquids or gases.
Gland packing has historically been the most common sealing method before mechanical seals were invented in the early 20th century. In fact, gland packing dates back more than 5,000 years when horse hair was braided and coated with animal fat for lubrication and additional sealing characteristics.
This sealing solution comprises materials such as braided or twisted fibres, graphite, PTFE, or other composite substances, engineered to endure high friction and compression. Due to its versatility, gland packing is employed across a broad spectrum of industries, including manufacturing, chemical processing, and water treatment, where it ensures the integrity and efficiency of various mechanical systems. Gland packing materials can also be customised to meet specific requirements.
Regular maintenance and proper installation of gland packing are also critical. When installed correctly, it minimises wear and tear on mechanical components, thereby extending the lifespan of the equipment. This not only reduces maintenance costs but also prevents unexpected breakdowns that could disrupt operations.
Choosing The Right Gland Packing Material
As mentioned above, there are a few materials that gland packing is usually made from, as well as custom compositions. At Dobson Gaskets, our skilled and experienced technicians will discuss your specific application and supply the right type of material for your gland packing needs. As a guide, the more standard materials can be chosen for their properties when looking to match with typical application types.
Gland Material Properties At A Glance
| Material | Temperature min/max | Chemical Resistance | Application Uses |
| Graphite | -200 to 450°C | Excellent | High-temperature applications, steam valves, and pumps |
| PTFE (Teflon) | -200 to 260°C | Excellent | Chemical processing, food industry, and pharmaceuticals |
| Aramid Fibre | -100 to 300°C | Good | Slurry pumps, abrasive media, and high-pressure applications |
| Carbon Fibre | -200 to 500°C | Very Good | High-temperature, high-pressure applications, and corrosive environments |
| Synthetic Fibre | -40 to 260°C | Good | General industrial applications, water treatment, and HVAC systems |
| Ceramic Fibre | Up to 1,200°C | Very Good | Extreme high-temperature applications, furnaces, and kilns |
| Flax | -30 to 120°C | Moderate | Water pumps, marine applications, and low-pressure systems |
| Glass Fibre | -100 to 500°C | Good | High-temperature applications, chemical plants, and furnaces |
The Advantages of Gland Packing
Gland Packing is the preferred choice of engineers where ease of installation is a priority, mechanical seals are not economically viable and the fluid within the application has aggressive properties. A good example is in the slurry pump in applications like mining and ore processing where large equipment size, large shaft movements, and aggressive liquids often make mechanical seals the inferior economic choice.
Traditionally, gland packing has degraded faster than mechanical seals due to the friction of the shaft wearing it away over time and has therefore needed to be replaced sooner. However, thanks to advancements in technology and design newer gland packing options currently on the market are able to last longer, extending the life of the seal.
Gland Packing Advantages At A Glance
- Versatility
Suitable for a wide range of applications, including pumps, valves, mixers, and agitators.
Effective in sealing fluids, gases, and slurries.
- Cost-Effective
Generally less expensive than mechanical seals.
Lower initial cost and maintenance expenses.
- Ease of Installation and Maintenance
Simple to install and adjust.
Easy to replace without dismantling the equipment.
- Durability
Can withstand harsh operating conditions, including high pressure and temperature.
Long-lasting when properly maintained.
- Flexibility
Adaptable to different sizes and shapes of equipment.
Available in various materials to suit specific applications, and can be customised for specific needs.
- Leakage Control
Provides a reliable seal to prevent leakage of fluids and gases.
Can be adjusted to control the amount of leakage.
- Operational Safety
Enhances the safety of operations by preventing the escape of hazardous substances.
Reduces the risk of equipment failure and associated accidents.
- Compatibility
Works well with a variety of shaft materials and surfaces.
Can be used in both dynamic (rotating) and static (stationary) sealing applications.
NEED ADVICE?
Talk to a Technician
With so many options and customisation opportunities, Dobson Gaskets can advise and supply the right gland packing for your specific application. Visit our Gland Packing page to find out more and get in touch with one of our expert technicians.