1．2 GLAND PACKINGS
(1) Types and applications
(a) What is gland packing?
Gland packing is a general term to mean those types of packing which are inserted in a stuffing box and apply tightness force to seal a fluid by means of compression, and it is also called simple compression packing.
Thanks to its simple construction and reasonable prices, gland packing has long been widely in use as a shaft sealing material for different types of equipment.
For this very reason, gland packing is associated with a strong image of rather an older type of packing, which leaves something to be desired in terms of performance. With the recent advent of new materials, however, gland packing has made rapid progress in its performance, changing itself out of all such recognition.
For example, while asbestos based packing has traditionally been used in a wide range of applications because of its excellent thermal and chemical resistance, the newer types of packing using fluorocarbon resins, carbon fibers, expanded graphite, etc. are gaining their appeal with a much longer service life and an incomparably higher sealing reliability sealing than asbestos packing.
Styles of gland packing
(b) Component materials
In general, braided gland packing is mainly composed of inorganic and organic fibers, additionally with various lubricants and binders.
Table 1.2.1 Types and Applications of Gland Packing
(c) Table indicating gland packing (applications & performance)
Gland packing will shorten its life and require frequent replacement unless a proper product is chosen according to the applications for which it is used (valves, pumps, equipment, etc.). Table 1.2.1, as a measure for selection of gland packing, lists the conforming performance values for different applications and conditions by component material.