What is Gland Packing? Complete Guide, Types, and Industrial Uses

What is Gland Packing? Complete Guide, Types, and Industrial Uses

Gland packing also known as compression packing—is a sealing material used to control leakage between moving parts, such as a pump shaft or valve stem, and the stationary housing. It is widely used in process industries where reliable, cost-effective sealing is required.

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How does a Gland Packing Work?

• Braided fibers are wrapped around the shaft or stem inside the stuffing box.
• When the gland follower is tightened, the packing compresses.
• This creates a controlled sealing pressure that minimizes leakage while allowing limited lubrication for shaft rotation.

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Key Components

• Shaft / Stem: The rotating or reciprocating component.
• Stuffing Box: Chamber where gland packing is installed.
• Gland Follower: Applies compression to the packing.
• Packing Rings: Layers of braided sealing material.

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Common Gland Packing Materials

1. Graphite Gland Packing
   • High temperature resistance (up to 650°C).
   • Excellent thermal conductivity.
   • Used in steam, hydrocarbon, and furnace applications.
2. PTFE Gland Packing
   • Chemically inert and non-stick.
   • Ideal for corrosive acids, alkalis, and chlorine service.
   • Operates up to 260°C.
3. Aramid (Kevlar) Gland Packing
   • High strength for abrasive media.
   • Common in slurry and paper pulp pumps.
4. Non-Asbestos Gland Packing
   • Environmentally safe substitute for asbestos.
   • Made from synthetic fibers and graphite.
5. Carbon Fiber Gland Packing
   • Suitable for high-speed rotary equipment.
   • Excellent dimensional stability.

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Types of Gland Packing

• Braided Gland Packing: Interlock or lattice braid for flexibility.
• Lubricated Gland Packing: Pre-impregnated with graphite or PTFE.
• Dry Gland Packing: For low-speed valves or manual adjustment.
• Hybrid Packing: Combination of aramid corners and graphite body.

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Applications

• Pumps: Centrifugal, reciprocating, and slurry pumps.
• Valves: Gate, globe, and control valves.
• Mixers and Agitators: Chemical and food industries.
• Power Plants: Turbine and boiler feed pumps.
• Refineries: Hydrocarbon and steam sealing.

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Advantages

• Economical sealing solution.
• Simple installation and maintenance.
• Tolerant to shaft misalignment.
• Works in wide temperature and pressure ranges.

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Limitations

• Requires periodic tightening.
• Generates frictional heat at high speeds.
• Not ideal for zero-leakage systems.

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Selection Criteria

• Media compatibility (acid, alkali, slurry).
• Shaft speed and temperature.
• Pressure rating.
• Packing density and cross-section.
• Compliance with standards (API 622, ASTM F2191).

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Industry Standards

• API 622: Testing of valve stem packing for fugitive emissions.
• ASTM F2191: Specification for compression packing.
• BS 4371: Industrial braided packing standards.