Basic Concepts

PTFE gland packing is a square or round braided sealing material made from polytetrafluoroethylene (PTFE) fibers. Installed in the stuffing boxes of pumps, valves, and agitators, it provides dynamic and static sealing for valve stems and rotating shafts by being compressed to fill the clearance space, thereby preventing fluid leakage. Commonly known as Teflon packing, it is a type of braided packing seal, distinct from expanded PTFE sheets or PTFE gaskets.

Advantages of PTFE Packing

1. Exceptional Corrosion Resistance:

Withstands pH levels from 0 to 14 and resists the vast majority of strong acids, strong alkalis, organic solvents, and aqua regia; unsuitable only for molten alkali metals and high-temperature fluorine gas.

2. High and Low-Temperature Resistance:

Suitable for long-term use between -200°C and 260°C; remains non-brittle at low temperatures and resistant to melting at high temperatures.

3. Self-Lubricating with Extremely Low Friction Coefficient:

Minimizes wear on pump shafts and valve stems; capable of short-term operation under oil-free conditions.

4. Clean and Non-Toxic:

Pure PTFE (free from graphite and impurities); meets cleanliness standards for food and pharmaceutical applications and does not contaminate materials.

5. Non-Absorbent and Mold-Resistant:

Does not swell or shrink when immersed in fresh water or seawater; offers excellent dimensional stability as well as resistance to aging and UV radiation.

6. Good Flexibility; Easy to Cut and Install

Main Types of PTFE Packing

1. White PTFE Packing (Oil-free, Pure PTFE):

Braided entirely from PTFE fibers; contains no graphite or lubricants; offers the highest level of cleanliness.

Applications: Food processing, pharmaceuticals, high-purity chemicals, pure water, and highly corrosive, clean media.

2. Lubricated White PTFE Packing:

Braided from pure PTFE and impregnated with silicone oil for lubrication; offers lower friction and superior heat dissipation.

Applications: High-speed rotating shafts and corrosive chemical pumps.

3. Black PTFE Packing (Graphite-filled PTFE):

PTFE blended with graphite; offers enhanced thermal conductivity, improved wear resistance, and reduced cold flow.

Applications: High-temperature environments, general acids/alkalis, steam, and hot oil; not suitable for clean media (graphite may contaminate the fluid).

4. Aramid-Interwoven Black/White PTFE Packing:

A blend of PTFE fibers and aramid fibers; offers significantly higher strength, extrusion resistance, wear resistance, and resistance to cold flow.

Applications: High-pressure and high-speed applications, media containing minor particulates, agitator shafts, and reciprocating pumps.

5. Split-Fiber PTFE Packing:

Braided from PTFE yarn produced via a stretching and splitting process; features a denser structure and superior sealing performance compared to standard PTFE packing.

Applications of PTFE Packing

Equipment: 

Centrifugal pumps, magnetic drive pumps, valve stems, stirred reactors, mixers, compressors, electroplating equipment.

Industries: 

1.Fine chemicals and pharmaceuticals: Pumps handling various corrosive media; reactor agitation shafts (preferably oil-free white PTFE)

2. Food and beverage: Food-grade white PTFE gland packing

3. Electroplating, water treatment, and ultrapure water industries

4. Petrochemicals and papermaking: Sealing for acids, alkalis, and solvents

5. Environmental protection and seawater circulation equipment

Contact us

If you would like to find out more about PTFE Packing, please contact us at export@weitengroup.com, www.weitengroup.com.