UNIT HEATER

A heater with electric resistance, steam, or hot water heating elements to heat the air. Natural or forced draft units are designed for wall mounting.

unit_heater water heat electric draft heating wall heater steam,

Related Terms

GAGE VALVE

A valve attached to a water column or drum for checking water level.

water water_column drum water_level valve gage gage_valve

A vertical tubular member connected at its top and bottom to the steam and water space respectively to a boiler, to which the water gage, gage valves, high and low water alarms and fuel cutoff may be connected.

gage water_column bottom low_level_alarm gauge_valve space steam water boiler fuel_cutoff fuel water_gauge high_level_alarm

TRY VALVES

Test valves on a water column used to verify the water level when the gauge glass is out of service.

water_column level water_level water gauge_glass test try_valves valves

TRY VALVE

One of three valves mounted on a boiler or water column within the visible range of the gauge glass and used to check the water level.

water_column try_valve valve water range gauge_glass boiler water_level valves

SOUNDING PIPE

A pipe leading to the bottom of an oil or water tank, for guiding a sounding tape or jointed rod when measuring the depth of liquid in the tank.
Sounding pipes in the engine room are normally fitted with deadweight cocks and screw caps. Caps and cocks should be closed at all times, except when sounding tanks.

water oil tank liquid bottom rod pipe depth sounding_tape sounding sounding_pipe

SHALLOW WATER EFFECT

The effect that due to the depth of water, the speed of the vessel and shape of the vessel's hull causes the vessel to sink deeper in the water especially in shallow water and at high speed. The vessel becomes sluggish in responding to the rudder.

water shallow_water_effect hull shallow depth high shape sink vessel shallow_water speed

PNEUMATIC CAISSON

A caisson having a chamber filled with compressed air at a pressure equal to the pressure of the water outside.

pneumatic_caisson caisson pressure chamber air compressed_air water

PHOTOTUBE CURRENT METER

A device for measuring the speed of water currents in which a perforated disk, which rotates with the current by means of a propeller, is placed in the path of a beam of light that is then reflected from a mirror onto a phototube.

phototube_current_meter speed current path light device beam water

PHLEGER CORER

A device for obtaining ocean bottom cores up to about 4 feet (1.2 meters) in length; consists of an upper tube, main body weight, and tailfin assembly with a check valve that prevents the flow of water into the upper section and a consequent washing out of the core sample while hoisting the corer.

phleger_corer bottom assembly sample ocean section core hoisting main flow check_valve valve device main_body check water

PERMISSIBLE VELOCITY

The highest velocity at which water is permitted to pass through a structure or conduit without excessive damage.

permissible_velocity velocity pass conduit structure water