GATE VALVE:

Also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The valve turns "righty-tighty; lefty-loosey."

 

GAS VALVE:

An electronic valve in the pool heater that directs gas flow from the meter to the pilot and the burner tray.

 

GASKET:

A gasket is a mechanical seal that fills the space between two objects, generally to prevent leakage between the two objects while under compression. Gaskets are commonly produced by cutting from sheet materials, such as gasket paper, rubber, silicone, metal, or a plastic polymer.

 

GROUND-FAULT CIRCUIT-INTERRUPTER:

A GFCI device protects a circuit from branching off by de-energizing the path of electricity very quickly when it senses current loss. An important safety device around water (the pool?).

 

GROUT:

A mortar or paste for filling crevices, esp. the gaps between wall or floor tiles.

 

GUNITE:

A mixture of cement, sand, and water applied through a pressure hose, producing a dense hard layer of concrete used in building for lining tunnels and structural repairs.