This Palmetto style 1390 PTFE and graphite compression packing seal protects pumps and valves from fluid leaks in general service applications. The interwoven braided packing seal is made of polytetrafluoroethylene (PTFE) yarn for resistance to most harsh chemicals, including solvents, acids, and bases. PTFE’s low coefficient of friction reduces shaft wear by minimizing drag and heat buildup between the packing and the shaft. Low-friction colloidal graphite is added to the packing to reduce thermal expansion and transfer heat away from the shaft to prevent glazing and scoring, extending the packing and sleeve life. Colloidal graphite also improves resistance to pitting and stress cracking. The packing seal is saturated with an inert lubricant that improves break-in time, reduces frictional heat, and prevents the packing from spinning with the shaft or stem, reducing the chance of scoring and wear. Style 1390 is a harder and stiffer packing than styles 1382 and 1389.
This packing seal is compatible with media in the pH range of 0-14, except for hot molten alkali metals and certain media in the 0-2 pH range. It will not hydrolyze in hot water like other fibers, such as aramid. It has a maximum pressure limit of 500 pounds per square inch (psi) in pumps and 1,500 psi in valves, and a shaft surface speed rating of 3,600 feet per minute (fpm). It operates to a maximum temperature of 500 degrees F (260 degrees C). Style 1390 is suitable for use in applications such as paper mill and chemical plant slurries, paper stock, caustic sewage, and reciprocating and high-pressure centrifugal pumps, among others.
| Maximum temperature ||500 degrees F (260 degrees C)|
| pH range ||0-14, except hot molten alkali metals and certain media in the 0-2 pH range |
| Pressure limit in pumps ||500 psi (34.5 bar) |
| Pressure limit in valves ||1,500 psi (103 bar) |
| Shaft surface speed ||3,600 fpm (18.3 m/s)|
Rope seals provide a pressure seal to help retain fluids and gases in a wide variety of commercial and industrial applications. They have a round, square, or rectangular cross section, and come in various braided designs including braid-over-braid, braid-over-core, laminated, twisted, or interwoven. Rope seals can be manufactured from a single material or a combination of materials that suit specific pressure, temperature, speed, and chemical applications. Some rope seals are impregnated with lubricant and have reinforced cores for improved performance in specific environments, such as extremely high temperatures. They can be used to create a static seal in fixed or slow-moving applications like expansion joints, doors, and valves, or a dynamic seal in equipment with reciprocating, rotating, or oscillating movement like centrifugal pumps, rotating stems, and blowers. Rope seals come in uncut lengths on spools or as precut molded rings. They are used in numerous industries including agriculture, oil and gas, automotive, aerospace, construction, and consumer goods.
Palmetto Inc. manufactures packing products for pumps and valves, such as compression packing seals, packing tools, gasket sheets, and fillers. The company, founded in 1872, is headquartered in Denton, MD.