Industrial Packing & Sealing: FAQ

Gland packing is a ring stack of braided, square-section cord compressed in a stuffing box around a shaft or stem. The gland squeezes the rings to form a controlled, self-adjusting seal that blocks fluid along the shaft.

It depends on speed, temperature, chemistry and shaft condition — from months on clean, cool, slow duty to weeks on hot, abrasive or poorly finished shafts. Correct material choice and staged installation are the biggest levers.

Most often under-tightening, shaft runout, thermal relaxation, or a chemically/thermally wrong material. Re-torque in stages and check the shaft; switch material if the service is outside its rating.

Just enough to stop leakage with a slight, acceptable weep — not as tight as possible. Over-tightening raises friction and shaft wear and can increase leakage as the shaft scores.

PTFE for broad chemical resistance at moderate temperature and easy installation; graphite for high heat, steam and tight emission limits. See the detailed comparison guides for valves and materials.

Yes — specify aramid or aramid-outer braid, which resists cut and abrasion from suspended solids far better than soft yarns.

Flexible graphite is typically stable to about 450–550 °C (higher with inconel-wire reinforcement and oxidation inhibitor), well beyond PTFE's ~260 °C limit.

Virgin PTFE in food/pharma grades meets FDA 21 CFR 177.1550 for food-contact use; confirm the grade and any fillers are approved for your application.

Packing seals a rotating or reciprocating shaft in a stuffing box; a gasket seals a static flange face between two fixed surfaces. They solve different leakage paths.

Commonly 4–6 rings of square braid sized to the box, with a lantern ring added mid-stack when a flush or quench connection is required.