GALVANIC CORROSION
An electrochemical reaction that may occur between a metal and a more chemically noble material such as another metal, carbon, or graphite. When both materials are immersed in an electrically conductive media called an electrolyte, a galvanic cell is formed and current flows between the two materials. The least noble material (called the anode) will corrode, while the more noble material (the cathode) will not.
GARTER SPRING
A helically coiled wire with its ends connected to form a ring. It is used in tension for maintaining a radial sealing force between element of a radial lip seal and a shaft.
GASKET
A deformable material, which, when clamped between essentially stationary faces, prevents the passage of matter through an opening or joint.
GASKET SPACER
A gasket material cut to fit in a stuffing box between braided packing rings. Gasket spacers may be used to provide protection against abrasive particles, to increase the pressure resistance of some packing sets, or to reduce the flow of fluid through the body of the braid.
GASKETING
Material in bulk form from which gaskets may be cut.
GAUGE
The thickness of a material; also the device used to measure material thickness.
GLAND
See "Packing Gland".
GLAND FOLLOWER
A part which protrudes into a stuffing box to compress a packing set or packing ring.
GLAND LOAD
The amount of load applied to a packing set. This may be expressed in terms of force (Lbs., N) or in terms of pressure (psi, kPa).
GLAND PRESSURE
The amount of pressure applied to a compression packing set by the gland follower, usually expressed in psi or kPa.
GLAND STUD
A threaded rod or eye bolt, extending from a valve or pump body, that is used to compress a packing set.
GROOVE
The area in which a hydraulic seal is contained for the purpose of sealing against a rod, or cylinder wall or an annular seal cavity.