Pressure in low side of refrigerating systems; also called suction pressure or low-side pressure.
Fluid opening/closing such as a gauge opening; to seat the joint where the valve stem goes through the valve body.
A form of unicellular microorganisms.
Plate or vane used to direct movement of a fluid within a confined area.
The point at which the heating capacity of a heat pumps equal to the heat losses of the structure it is heating.
A check valve that uses a ball to permit flow in one direction only.
Unit of pressure. One bar equals .9869 atmosphere (approximately one atmosphere, 14.51 psi).
Instrument for measuring atmospheric pressure.
Liquid solution used for cleaning, plating, or maintaining a specified temperature.
Electricity-producing cells that use interaction of metals and chemicals to create electrical current flow.
Heat exchanger in which water flows by gravity over the outside of tubes or plates.
Low-friction device for supporting and aligning a moving part.
Corrugated cylindrical container that moves as pressures change, or provides a seal during movement of parts.
Method of sealing the valve stem. The ends of the sealing material are fastened to the bonnet and to the stem. Seal expands and contracts with the stem level.
A rubber-like, continuous loop placed between two or more pulleys to transfer rotary motion.
Coil spring that is placed on inside or outside of tubing to keep it from collapsing while bending.
In stream of liquid, the sum of elevation head, pressure head, and velocity remains constant along any line of flow, provided no work is done by or upon liquid on course of its flow; decreases in proportion to energy lost in flow.
Temperature regulating or indicating device that works on the principle that two dissimilar metals with unequal expansion rates, welded together, will bend as temperatures change.
Airborne microorganisms derived from viruses, bacteria, fungi, protozoa, mites, and pollen.
Low-temperature evaporator that uses a fan to force air over that evaporator surface.
Slowly reducing the pressure of liquid or gas from a system by opening a valve slightly.
Valve with small opening inside that permits a minimum fluid flow when valve is closed.
A mixture of various refrigerants.
With respect to fuses, a fuse that has been melted, breaking the electric circuit and preventing overload.
Closed container in which a liquid may be heated and vaporized.
A boiler operating with water temperature and water pressure above low-pressure boiler ratings.
Seldom-used term equivalent to a heating capacity of 33,475 Btu/hr. (9804 watts).
A boiler operating with up to 250F (121C) water temperature and 160 psi water pressure or less.
The temperature of a liquid at which it changes to a gas under a pressure of 14.7 psia (101.3 kPa).
Temperature at which a fluid changes form a liquid to a gas.
In a furnace, the sheet metal chamber where heat collects before being distributed.
Common term applied to the use of a compressor as the first stage in a cascade refrigerating system.
Diameter of a hole. Inside diameter of a cylinder.
Thin-walled tube of elastic metal flattened and bent into a circular shape that tends to straighten as inside pressure is increased. Used in pressure gauges.
Law of Physics: The volume and pressure of a gas vary inversely if the temperature remains the same. Example: If the pressure is doubled on a quantity of gas, its volume is reduced one-half. If the volume is doubled, gas has its pressure reduced by one-half.
Method of joining metals with nonferrous (without iron) filler using heat between 800F (427C) and the melting point of base metals.
Strip of wood or plastic used to cover the joint between the outside case and inside liner of the refrigerator.
Space in hot water or steam boilers between the end of the tubing and the jacket.
Water saturated with a chemical such as salt.
British thermal unit (Btu)
Quantity of heat required to raise temperature of one pound of water one degree Fahrenheit.
Building Related Illness (BRI)
An illness caused by an airborne virus in a building.
Electrical terminal attached to a compressor dome.
Part of sealed fluid device that reacts to temperature. Used to measure temperature or to control a mechanism.
Space where ice or cooling element is placed in commercial installations.
Device in which burning of fuel takes place.
Liquid hydrocarbon (C4H10) commonly used as fuel for heating purposes.
Passage around a regular passage.
A cycle using a bypass line with either hot gas or liquid used to defrost an evaporator or for low pressure control.