Gland Packing
Industrial Braided Packing for Pumps, Valves and Process Equipment
What Is Gland Packing?
Gland packing, also known as sealing packing or compression packing, is a traditional but highly effective sealing material used in pumps, valves, mixers, agitators, compressors and other rotating or reciprocating equipment.
It is usually made from soft braided fibers such as PTFE, graphite, aramid, carbon fiber, synthetic fiber, or flexible graphite yarn. The packing is installed into the equipment’s stuffing box and compressed by a gland follower. Under compression, the packing expands radially and forms a seal against the shaft, sleeve, or valve stem, helping control fluid leakage.
We supply gland packing for pumps, valves, mixers, agitators and general industrial sealing applications
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Applications of Gland Packing
Because of its wide material options, easy installation, strong adaptability and reliable sealing performance, gland packing is still widely used in:
centrifugal pumps
Rotary Pumps
reciprocating compressors
vacuum pumps
mixers and agitators
ship propeller shaft seals
industrial valves
high-temperature and high-pressure equipment
Main Types of Gland Packing and Their Applications
Different packing materials are designed for different operating conditions. Correct material selection can greatly improve sealing reliability, reduce shaft wear and extend service life.
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How to Choose the Right Gland Packing
Before selecting gland packing, evaluate the full operating environment. A packing that works well in one system may fail quickly in another.
1. Medium
Identify whether the fluid is:
acidic or alkaline; abrasive or clean; crystallizing or sticky; food-grade or non-food-grade; oxidizing or non-oxidizing; slurry, gas, steam, oil or solvent
For example, PTFE packing is often preferred for strong chemical resistance and clean service, while graphite packing is widely used in high-temperature steam and hydrocarbon service.
2. Temperature
Temperature directly affects packing life. PTFE materials are excellent for corrosive chemical service but may not be suitable for extreme high-temperature steam. Graphite packing is usually a better choice for high-temperature valves and steam systems.
3. Pressure
Higher pressure requires stronger packing construction and better anti-extrusion performance. Reinforced graphite packing, aramid packing or carbon fiber packing may be needed for demanding pressure conditions.
4. Shaft Speed
Rotating equipment generates friction heat. Higher shaft speed requires better lubrication and heat dissipation. Graphite and carbon-based packings are often selected for high-speed applications because they can handle heat better.
5. Equipment Condition
Old or worn equipment may have shaft runout, sleeve wear or enlarged stuffing box clearance. In such cases, packing with better elasticity or reinforced structure may improve sealing stability.
How to Calculate Gland Packing Size
Correct packing size is the first step to successful sealing.
Use the following formula:
Packing cross-section = (Stuffing box inside diameter – Shaft or stem outside diameter) / 2
For example, if the stuffing box inside diameter is 60 mm and the shaft diameter is 40 mm:
(60 – 40) / 2 = 10 mm
So the required packing size is 10 mm × 10 mm.
For old equipment with worn shafts or enlarged clearances, a slightly larger packing size may be required, but excessive oversizing can cause high friction, overheating and difficult installation.
Gland Packing Installation Guide
Correct installation is important for packing performance and equipment life. A typical installation includes:
1. Remove the old packing completely.
2. Clean and inspect the shaft, sleeve and stuffing box.
3. Confirm the correct packing size.
4. Cut individual packing rings according to the packing and equipment manufacturer’s recommended method.
5. Install and seat each ring separately.
6. Stagger ring joints according to the applicable installation procedure.
7. Tighten the gland follower evenly.
8. Start and adjust the equipment according to the packing type and operating requirements.
Packing should not be over-tightened to compensate for worn shafts, flange misalignment or incorrect material selection.
Need Gland Packing for Your Equipment?
For product selection or quotation, please provide:
Equipment type
Packing size or stuffing-box dimensions
Process medium
Operating temperature
Operating pressure
Shaft speed or RPM where applicable
Quantity
We can help identify an appropriate PTFE, graphite, aramid, carbon, or other gland packing according to the actual operating conditions.