Jargon Buster - G

Gasketed plate heat exchanger
A type of heat exchanger in which the heat exchanging plates are sealed together with a gasket material.
Gate valve
A type of linear movement valve. It usually consists of a wedge shaped gate which moves in the valve to open, or shut off the flow through it. They normally have a low pressure drop as the gate fully retracts into the bonnet.
Gauge glass
A device connected to, but outside, a closed system that allows the barrier between two substances of different density to be monitored by sight. A typical example might be the level of the water in a steam boiler or in a hotwell boiler feed water tank.
Gauge pressure
A measure of the pressure in a system. It is a measure of the force per unit area exerted by a medium using atmospheric pressure as the zero reference.
GEM trap
A venturi orifice type steam trap which has no moving parts. It is made by GEM. GEM is owned by Canadian company Thermal Energy International Inc. The acronym GEM stands for Gardner Energy Management, and was so named after Tim Gardner the original founder of Gardner Energy Management Ltd.
Gestra
A company which manufactures a wide range of products for the steam industry. Of German origin it is now part of the Flowserve Corporation.
Gilflo
A type of steam meter manufactured by Spirax Sarco. It is a variable area type flowmeter.
Globe valve
A type of linear movement valve. It is a very popular type of valve. A valve disc opens or shuts off against a valve seat. The flow of medium through the valve must change course so the pressure drop is higher than a gate valve. A globe valve opens more rapidly than a gate valve however.
Gravity return system
Typically used to describe a condensate system returning to a collecting point by means of a sloping pipe system.
Gunmetal
A type of bronze.