The Marvel of PTFE Gland Packing: An Essential Component in Industrial Sealing
PTFE Gland Packing, made of Polytetrafluoroethylene, is a marvel in the world of industrial sealing. Known for its exceptional chemical resistance and low friction, it plays a crucial role in preventing leakage of fluids and gases from industrial equipment.Get more news about Ptfe Gland Packing,you can vist our website!
Gland packings are a traditional and still popular way of solving dynamic sealing constructions. They damp leakage between the moving part and the housing, essential for the efficiency of mixers, pumps, valves, and other industrial equipment in rotary motion. For decades, the sealant was simply a plant fibre saturated with grease placed in a gland between the pump casing and the rotating shaft. The advantage of this solution is still simplicity of construction and gradual signalling of wear and tear by increasing leakage.
Modern pumping systems have an extremely wide range of materials to meet the high requirements in terms of chemical resistance, shaft speed, pressure, and temperature. The packing is designed to radially compensate the gap on the rotating shaft, thus controlling the leakage of the medium and preventing the loss of valuable process fluids and unnecessary emissions into the environment.
PTFE Gland packings are made of specially selected polytetrafluoroethylene (PTFE) filaments or exfoliated graphite acrylic fibre. The braiding process guarantees a solid but durable substance of constant consistency, ideal for continuous operation at varying temperature. Our PTFE Compression Packing product line includes valve stem packing, food grade packing, and chemically resistant packing for pumps and rotary equipment.
The PTFE packings can stand almost every chemical substance known. The PTFE compression packings offer great temperature resistance up to +60°C as the PTFE dispersion ensures a low friction finish and prevents leakage through the braid.
An additional criterion to consider is the rotational movement of the shaft. The rotation of the shaft generates significant amounts of heat due to friction and can cause excessive wear of the packing box components. It is important to select the type of packing that can withstand the required working conditions and is chemically resistant to the working medium.
In the case of dynamic seals, consideration of the T max – maximum temperature is essential for the performance of the sealant. Most materials have a positive temperature coefficient of friction, which means that when a critical temperature is exceeded, the friction starts to increase exponentially. This phenomenon usually leads to overheating and burnout of machine parts and, in the case of seals, to grilling and loss of sealing properties.
Temperature of the medium is also not the same as the packing temperature, as the gland operates at a higher temperature due to the friction. A safety margin of at least +50°C is assumed for centrifugal pumps operating without an additional gland cooling system. A good solution is the use of materials resistant to burn-out, based on graphite and carbon fibres.
The temperature issue can also be solved structurally by an additional sealant flushing system. However, it does not change the fact that the selection of packing in terms of temperature range is of key importance and its omission may lead to immediate failure of the device.