A measure having as its zero point or base the complete absence of the entity being measured.
The pressure above zero absolute, i.e., the sum of atmospheric and gauge pressure. In vacuum related work it is usually expressed in millimeters, or inches, of mercury.
A statistical quality control method that seeks to determine the quality of a product by sampling a small portion of it. It does not assure that 100 percent of the product is acceptable, but reduces the likelihood of acceptance of a defective product.
A container in which fluid (generally nitrogen) is stored under pressure as a source of fluid power.
A unit of area used in English-speaking countries, equal to 4,840 square yards (0.405 hectares).
A device for converting pneumatic or hydraulic energy into mechanical energy. A motor or cylinder.
A substance capable of holding materials together by surface attachment. It is a general term and includes cements, mucilage, and paste, as well as glue.
Plant parts, primarily stalks and leaves, not removed from the fields with the primary food or fiber product. Examples include corn stover (stalks, leaves, husks, and cobs); wheat straw; and rice straw.
A device for amplifying the error signal sufficiently to cause actuation of the stroke control. Several types of servo amplifiers are used at the present time: electronic (DC, AC, phase sensitive, and magnetic) and mechanical.
Decomposition of biological wastes by micro-organisms, usually under wet conditions, in the absence of air (oxygen), to produce a gas comprising mostly methane and carbon dioxide.
Exhibiting different properties when measured along different axes. In general, fibrous materials such as wood are anisotropic.
A ring shaped area - often refers to the net effective area of the rod side of a cylinder piston, i.e., the piston area minus the cross-sectional area of the rod.
The wide variety of aquatic biomass resources, such as algae, giant kelp, other seaweed, and water hyacinth. Certain microalgae can produce hydrogen and oxygen while others manufacture hydrocarbons and a host of other products. Microalgae examples include Chlorella, Dunaliella, and Euglena.
Pressure exerted by the atmosphere at any specific location. (Sea level pressure is approximately 14.7 pounds per square inch absolute.)
A push (compression) or pull (tension) acting along the length of a member, expressed in kilonewtons (pounds).
The axial force acting at a point along the length of a member divided by the cross-sectional area of a member, expressed in kilopascals (pounds per square inch).
A condition where pipe connections are on normally unexposed surfaces of hydraulic equipment. (Gasket mounted units are back connected.)
A pressure in series. Usually refers to pressure existing on the discharge side of a load. It adds to the pressure required to move the load.
A small single-cell organism. Bacteria do not have an organized nucleus, but they do have a cell membrane and protective cell wall. Bacteria can be used to ferment sugars to ethanol.
The amount of energy contained in a barrel of crude oil, i.e. approximately 6.1 GJ (5.8 million Btu), equivalent to 1,700 kWh. A "petroleum barrel" is a liquid measure equal to 42 U.S. gallons (35 Imperial gallons or 159 liters); about 7.2 barrels are equivalent to one tonne of oil (metric).
The use of fermentation or anaerobic digestion to produce fuels and chemicals from organic sources.
Useful, renewable energy produced from organic matter. The conversion of the complex carbohydrates in organic matter to energy. Organic matter may either be used directly as a fuel or processed into liquids and gases.
The quantity of biological matter of one or more species present on a unit area. With respect to trees, biomass can be expressed in terms of various components (wood, bark, foliage, roots, etc.) of all trees on a unit area or of a single tree; biomass quantities of trees are commonly expressed on an oven-dry weight basis.
Biomass boilers burn bark, sander dust and other wood-related scrap not usable in product production. Also called "hogged fuel" boilers, biomass boilers make steam and heat for mill use.
Liquid, solid, or gaseous fuel produced by conversion of biomass. Examples include bioethanol from sugar cane or corn, charcoal or woodchips, and biogas from anaerobic decomposition of wastes.
Byproducts from processing all forms of biomass that have significant energy potential. Because these residues are already collected at the point of processing, they can be convenient and relatively inexpensive sources of biomass for energy.
The smallest unit of memory in a computer. A bit is a single digit and can only have the values 0 or 1. Bits are combined into words of memory.
To divert a specific controllable portion of hydraulic pump delivery directly to reservoir.
The unit load applied in tension, compression, flexure, cleavage, or shear, required to break an adhesive assembly, with failure occurring in or near the plane of the bond.
Material that weighs 2,000 pounds at zero percent moisture content. Also known as an Ovendry ton or Bone Dry Metric Ton.
A quantity of wood residue that would weigh 2,400 pounds at zero percent moisture content.
A cogeneration system in which steam is used first for process heat and then for electric power production.
As in welding, a method of adhering or soldering carbide or other hard metal teeth inserts, or joining pieces of metal.
A device which permits air to move in and out of a container or component to maintain atmospheric pressure.
The quantity of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
1. Adjusting the control or recording equipment to reflect the actual control or recording
2. Procedures that involve scanning an object of known size. Calibration is used to adjust
scanner readings for greater accuracy.
The potential heat-production value of a wood source. Depends on the cellulose-lignin ratio, the percentage of extractives, and the moisture content.
The velocity of the gas in the passages between the filter units in the filter house of a gas filter.
The combination of solid-liquid adhesion and surface tension by which liquid moves through a cellular structure.
The total investment needed to complete a project and bring it to a commercially operable status. The cost of construction of a new plant or the expenditures for the purchase/acquisition of existing facilities.
A colorless, odorless gas produced by respiration and combustion of carbon-containing fuels. Plants use it as a food in the photosynthesis process.
1. The replaceable element of a fluid filter.
2. The pumping unit from a vane pump, composed of the rotor, ring, vanes and one or both side
A substance that increases the rate of a chemical reaction, without being consumed or produced by the reaction. Enzymes are catalysts for many biochemical reactions.
A localized gaseous condition within a liquid stream which occurs where the pressure is reduced to the vapor pressure.
One of the major structural materials in the plant cell walls that can be utilized by microorganisms in the rumen.
The international temperature scale in which water freezes at 0 and boils at 100 under normal atmospheric conditions. °C = (°F - 32) ÷ 1.8.
A metric unit of length equal to one hundredth of a metre. 2.54 cm is equal to one inch.
The force which impels a thing, or parts of a thing, outward from a center of rotation.
A fluid passage, the length of which is large with respect to its cross-sectional dimension.
The remains of solid biomass that has been incompletely combusted, such as charcoal if wood is incompletely burned.
The pressure at which replenishing fluid is forced into the hydraulic system (above atmospheric pressure).
1. To replenish a hydraulic system above atmospheric pressure.
2. To fill an accumulator with fluid under pressure. (See Precharge pressure)
Thin, short pieces of wood used as a raw material for biomass fuel, pulping and fiberboard production. The product of chippers. Chips are larger and coarser than sawdust.
An arrangement of components interconnected to perform a specific function within a system.
A system in which the output of one or more elements is compared to some other signal to provide an actuating signal to control the output of the loop.
Refers to the production of usable steam and electricity using a particular kind of fuel (for example, woodchips, oil, coal, hydro).
Two or more generation processes in series or in parallel, configured to optimize the energy output of the system.
The air fed to a fire to provide oxygen for combustion of fuel. It may be preheated before injection into a furnace.
The transformation of biomass fuel into heat, chemicals, and gases through chemical combination of hydrogen and carbon in the fuel with oxygen in the air.
(actual heat produced by combustion) divided by (total heat potential of the fuel consumed)
A displacement control for variable pumps and motors which alters displacement in response to pressure changes in the system as related to its adjusted pressure setting.
Built-up, bonded products consisting wholly of natural wood, or in combination with metals, plastics, etc.
The change in volume of a unit volume of a fluid when it is subjected to a unit change in pressure.
A device used to regulate the function of a unit (See Hydraulic control, Manual control, Mechanical control, and Compensator control).
Fabricated metal cabinet housing buttons and switches for the control of a machine center.
A stack of wood consisting of 128 cubic feet (3.62 cubic meters). A cord has standard dimensions of 4 x 4 x 8 feet, including air space and bark.
A pressure control valve which maintains back pressure to prevent a load from falling.
To change the properties of an adhesive by chemical reaction (which may be condensation, polymerization, or vulcanization) and thereby develop maximum strength. Usually accomplished by the action of heat or a catalyst with or without pressure.
A device sometimes built into the ends of a hydraulic or pneumatic cylinder which restricts the flow of fluid at the outlet port, thereby arresting the motion of the piston rod.
A device which converts fluid power or air into linear mechanical force and motion. It usually consists of a movable element such as a piston and piston rod, plunger rod, plunger or ram, operating within a cylindrical bore.
The region or band of no response where an error signal will not cause a corresponding actuation of the controlled variable.
When applied to feed rations, describes the amount of nutrients within a measurement unit of the total ration.
To close the vent connection of a pressure control valve permitting the valve to function at its adjusted pressure setting.
The algebraic summation of the current in the torque motor; measured in MA (milliamperes).
An airtight vessel or enclosure in which bacteria decomposes biomass in water to produce biogas.
The quantity of fluid which can pass through a pump, motor or cylinder in a single revolution or stroke.
A low amplitude, relatively high frequency periodic electrical signal, sometimes superimposed on the servo valve input to improve system resolution. Dither is expressed by the dither frequency (Hz) and the peak-to-peak dither current amplitude (ma).
A gasifier in which the product gases pass through a combustion zone at the bottom of the gasifier.
A passage in, or a line from, a hydraulic component which returns leakage fluid independently to reservoir or to a vented manifold.
The ratio of output to input. Volumetric efficiency of a pump is the actual output in gpm divided by the theoretical or design output. The overall efficiency of a hydraulic system is the output power divided by the input power. Efficiency is usually expressed as a percent.
The liquid or gas discharged from a process or chemical reactor, usually containing residues from that process.
A directional type valve which receives a variable or controlled electrical signal and which controls or meters hydraulic flow.
Device attached to a moving chain that produces an electrical signal each time the chain moves a fixed distance. The encoder is attached to the chain and used to track the movement of the pieces through a scanner.
Are fast-growing crops that are grown for the specific purpose of producing energy (electricity, thermal energy, solid or liquid fuels) from all or part of the resulting plant.
The aggregate of physical, chemical and biological factors that act upon an organism or an ecological community and ultimately determine its form and survival.
A protein or protein-based molecule that speeds up chemical reactions occurring in living things. Enzymes act as catalysts for a single reaction, converting a specific set of reactants into specific products.
A colorless, flammable liquid produced by fermentation of sugars. Ethanol is used as a fuel oxygenate. Ethanol is the alcohol found in alcoholic beverages.
Refers to the quantity of air supplied that exceeds the minimum necessary to support the combustion chemistry.
A cost or benefit not accounted for in the price of goods or services. Often refers to the cost of pollution and other environmental impacts.
The temperature scale in which water freezes at 32 degrees F and boils at 212 degrees F under normal atmospheric conditions. F = (C x 1.8) + 32.
Fans whose motors turn at infinitely variable speeds by varying the line frequency of the power source.
Any closed circuit consisting of one or more forward elements and one or more feedback elements.
The speed of a machine centre (canter, planer, etc.) usually expressed in feet per minute.
Conversion of carbon-containing compounds by micro-organisms for production of fuels and chemicals such as alcohols, acids or energy-rich gases.
A device whose primary function is the retention by a porous media of insoluble contaminants from a fluid.
Power which is guaranteed by the supplier to be available at all times during a period covered by a commitment.
1. A liquid or gas.
2. A liquid that is specially compounded for use as a power-transmitting medium in a hydraulic
Vessel where a fluidized bed is formed by blowing air up through a layer of inert particles (such as sand or limestone) at a rate that causes the particles to go into suspension and continuous motion. The super-hot bed material increases combustion efficiency by its direct contact with the fuel.
A control valve which ports oil to an actuator so the resulting output motion is proportional to the input motion to the valve.
Any push or pull measured in units of weight. In hydraulics, total force is expressed by the product P (force per unit area) and the area of the surface on which the pressure acts. F = P x A.
Material not harvested or removed from logging sites in commercial hardwood and softwood stands as well as material resulting from forest management operations such as precommercial thinnings and removal of dead and dying trees.
1. The number of cycles per second of alternating current (example: 60 cycles per second or 60
hertz per second).
2. The number of times an action occurs in a unit of time. Frequency is the basis of all sound.
A pump or motor's basic frequency is equal to its speed in revolutions per second multiplied
by the number of pumping chambers.
A condition wherein piping connections are on normally exposed surfaces of hydraulic components.
A mobile machine mounted on a wheeled or tracked chassis, equipped with a grapple, tuck, bucket, or fork-lift device, and employed in the loading, unloading, stacking, or sorting of logs or materials.
The series of steps required to produce electricity. The fuel cycle includes acquiring the raw fuel source, processing and cleaning the fuel, transport, electricity generation, waste management and plant decommissioning.
In a filter, the condition where all the fluid must pass through the filter element or medium.
An enclosed chamber or container used to burn biomass in a controlled manner to produce heat for space or process heating.
A unit of volume. A US gallon is equal to 4 quarts or 231 cubic inches (approximately 3.79 liters). A British imperial gallon is equal to four quarts or 4.55 liters.
A device for converting solid fuel into gaseous fuel. In biomass systems, the process is referred to as pyrolitic distillation.
A pressure scale which ignores atmospheric pressure. Its zero point is 14.7 psi absolute.
Originally, a hard gelatin obtained from hides, tendons, cartilage, bones, etc., of animals. Also, an adhesive prepared from this substance by heating with water. Through general use the term is now synonymous with the term "Adhesive".
A liquid by-product of biodiesel production. Glycerin is used in the manufacture of dynamite, cosmetics, liquid soaps, inks, and lubricants.
A metric unit of weight equal to one thousandth of a kilogram; one ounce is approximately 28 grams.
The effect of certain gases in the Earth's atmosphere in trapping heat from the sun.
Gases that provide an insulating effect in the earth's atmosphere, potentially leading to global climate change. These gases include carbon dioxide, methane, nitrous oxide, ozone, and water vapour.
The height of a column or body of fluid above a given point expressed in linear units. Head is often used to indicate gage pressure. Pressure is equal to the height times the density of the fluid.
The form of energy that has the capacity to create warmth or to increase the temperature of a substance. Any energy that is wasted or used to overcome friction is converted to heat. Heat is measured in calories or British thermal units (Btu's). One Btu is the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.
The amount of fuel energy required by a power plant to produce one kilowatt-hour of electrical output.
A metric unit of area, 100 metres by 100 metres (10,000 square metres); equivalent to 2.471 acres.
The polysaccharide fraction existing in the cell wall of the plant. It is similar to cellulose but is only partially digestible in the rumen.
Non-woody type of vegetation, usually lacking permanent strong stems, such as grasses, cereals and canola (rape).
Perennial non-woody crops that are harvested annually, though they may take 2 to 3 years to reach full productivity. Examples include: Switchgrass, Reed canarygrass, Miscanthus, and Giant reed.
The maximum potential energy in dry fuel. For wood, the range is from 7,600 to 9,600 Btu/lb (17.7 to 22.3 GJ/t).
Waste wood that is used for generation of heat and process energy; made by reducing bark to a usable size.
The power required to lift 550 pounds one foot in one second or 33,000 pounds one foot in one minute. A horsepower is equal to 746 watts or to 42.2 British thermal units per minute.
A condition of equal opposed hydraulic forces acting on a part in a hydraulic component.
A chemical reaction that releases sugars, which are normally linked together in complex chains. In ethanol production, hydrolysis reactions are used to break down the cellulose and hemicellulose in the biomass.
A type of furnace in which fuel enters at the top part of a grate in a continuous ribbon, passes over the upper drying section where moisture is removed, and descends into the lower burning section. Ash is removed at the lower part of the grate.
Conversion of biomass to a liquid fuel through a synthesis gas intermediate step.
1. A unit of energy equal to the work done when a force of one newton acts through a distance
of one metre. One joule is equivalent to one watt second or 0.737 foot pounds.
2. A unit of electrical energy equal to the work done when a current of one ampere is passed
through a resistance of one ohm for one second.
Stick or handle type input device mounted on the operator's console. Some joysticks have buttons mounted on the handle. Moving the joystick handle can send either discrete or analog input signals to the PLC.
A small, parallel-sided piece, flat or tapered on top, for securing pulleys and other parts to shafts.
The basic unit of mass in the SI system, equal to 1,000 grams (approximately 2.2 lbs).
A measure of energy equivalent to the expenditure of one kilowatt for one hour. For example, 1 kWh will light a 100-watt light bulb for 10 hours. 1 kWh = 3,413 Btu.
A measure of electrical power equal to 1,000 watts. 1 kW = 3,413 Btu/hr = 1.341 horsepower.
A hydraulically operated loading boom whose mechanical action imitates the human arm. Common on "forwarders".
A product made by bonding together two or more layers (laminations) of material or materials.
A type of biogas that is generated by decomposition of organic material at landfill disposal sites.
The present value of the cost of a resource, including capital, financing and operating costs, expressed as a stream of equal annual payments. By levelizing costs, resources with different lifetimes and generating capabilities can be compared.
A gain in output force over input force by sacrificing the distance moved. Mechanical advantage or force multiplication.
The height a body or column of fluid is raised; for instance, from the reservoir to the pump inlet. Lift is sometimes used to express a negative pressure or vacuum. The opposite of head.
A complex indigestible substance that is a major structural component of mature plants. It is contained in the fibrous portion of stems, leaves, cobs and hulls of plants.
Electrical device that transmits an electrical signal when in physical contact with an object.
Basic unit of volume in the metric system equal to 1,000 cubic centimetres (1.056 US quarts).
Any of a variety of machines, wheel or track mounted, designed primarily to lift and load a truck, train or other mode of transportation.
A control actuated by the operator, regardless of the means of actuation. Example: Lever or foot pedal control for directional valves.
A relationship, often portrayed in a diagram, that shows how all components of a raw material are allocated and used.
Any control actuated by linkages, gears, screws, cams or other mechanical elements.
A unit of linear measurement on land, equivalent to 5,280 feet (1,760 yd) or 1.6 kilometres.
A common method of pricing electricity in the U.S. Tenths of a U.S. cent per kilowatt hour.
To control within an infinite range between 0 percent and 100 percent as opposed to on/off control.
A device which converts electricity or hydraulic fluid power into mechanical force and motion. It usually provides rotary mechanical motion.
Residential, commercial, and institutional post-consumer wastes contain a significant proportion of plant-derived organic material that constitutes a renewable energy resource. Waste paper, cardboard, construction and demolition wood waste, and yard wastes are examples of biomass resources in municipal wastes.
The sum of the costs and benefits of a project or activity. Future benefits and costs are discounted to account for interest costs.
Unit of force equivalent to the force that produces an acceleration of one metre per second per second on a mass of one kilogram.
The transformation of atmospheric nitrogen into nitrogen compounds that can be used by growing plants.
One in which pump delivery flows freely through the system and back to the reservoir in neutral.
One in which all ports are interconnected and open to each other in the center or neutral position.
An oxygenate is a compound which contains oxygen in its molecular structure. Ethanol and biodiesel act as oxygenates when they are blended with conventional fuels. Oxygenated fuel improves combustion efficiency and reduces tailpipe emissions of CO.
Device used to detect the presence of an object. A photocell is composed of a transmitter, which transmits an infrared signal to a receiver or reflector.
A process that plants use to synthesize nutrients from water and minerals using sunlight.
A long, heavy timber, round or square, driven deep into the ground to provide a secure foundation for structures built on soft, wet, or submerged sites (e.g., landing stages, bridge abutments).
The size of a system between the small laboratory model size (bench scale) and a full-size system.
An auxiliary valve used to control the operation of another valve. The controlling stage of a 2-stage valve.
A cylindrically shaped part which fits within a cylinder and transmits or receives motion by means of a connecting rod.
Programmable logic controllers. Industrial computer with I/O capability, which programs in ladder-relay logic.
A cylindrically shaped part which has only one diameter and is used to transmit thrust. A ram.
A characteristic of a pump or motor which has the inlet positively sealed from the outlet so that fluid cannot recirculate in the component.
A control element in the servo system which measures and controls electrical potential.
An integral power supply unit usually containing a pump, reservoir, relief valve and directional control.
The pressure of compressed gas in an accumulator prior to the admission of liquid.
The worth of future receipts or costs expressed in current value. To obtain present value, an interest rate is used to discount future receipts or costs.
Force per unit area. Usually measured in pounds per square inch (PSI) or kilopascals (kPa). A kilopascal is equal to 1000 newtons per square metre or 0.0102 kg/sq cm (0.145 lb/sq in).
The line carrying the fluid from the pump outlet to the pressurized port of the actuator.
The difference between the cracking pressure of a valve and the pressure reached when the valve is passing full flow.
A valve which limits the maximum pressure at its outlet regardless of the inlet pressure.
1. An electric switch operated by fluid pressure.
2. Switches that read the available pressure in air and hydraulic lines. These switches are
often used as a safety feature, to prevent equipment from operating when there is not enough
air pressure or hydraulic fluid pressure.
Heat used in an industrial process rather than for space heating or other housekeeping purposes.
Fuel gas high in carbon monoxide (CO) and hydrogen (H2), produced by burning a solid fuel with insufficient air or by passing a mixture of air and steam through a burning bed of solid fuel.
In a filter, the condition where part of the flow passes through the filter element in proportion to pressure drop.
Photoelectric switches that are triggered as a piece passes near them. Proximity switches are used to detect the presence or absence of material.
The thermal decomposition of biomass at high temperatures in the absence of air. The end product of pyrolysis is a mixture of solids (char), liquids (oxygenated oils), and gases (methane, carbon monoxide, and carbon dioxide).
One quadrillion Btu (10^15 Btu) = 1.055 exajoules (EJ), or approximately 172 million barrels of oil equivalent.
Any activity that helps to maximize the value of the raw material through all phases of the manufacturing process.
A single-acting cylinder with a single diameter plunger rather than a piston and rod. The plunger in a ram-type cylinder.
1. Product recovery: An expression of the amount of product (nominal or actual) that can be
manufactured from a given input of raw material.
2. Logging recovery: The volume or weight of logs that can be harvested from a given volume of
A boiler that recovers process chemicals for re-use and creates process steam with the heat it generates.
A lining, usually of ceramic, capable of resisting and maintaining high temperatures.
A piping arrangement for a differential type cylinder in which discharge fluid from the rod end combines with pump delivery to be directed into the head end.
Ratio of the amount of water vapour present in the air to that which the air would hold at saturation at the same temperature. It is usually considered on the basis of the weight of the vapour but, for accuracy, should be considered on the basis of vapour pressures.
A pressure operated valve which by-passes pump delivery to the reservoir, limiting system pressure to a predetermined maximum value.
The amount by which the utility's total electric power capacity exceeds maximum electric demand.
Byproducts from processing all forms of biomass that have significant energy potential. Because these residues are already collected at the point of processing, they can be convenient and relatively inexpensive sources of biomass for energy.
An ingredient of coatings which acts as a binder and gives the coating physical properties such as hardness and durability.
The interest rate at which the net present value of a project is zero. Multiple values are possible.
A four-way directional valve used to reverse a double-acting cylinder or reversible motor.
A temperature measuring device that measures the change in electrical resistance to determine temperature (resistive thermal device).
An element of the PLC ladder logic program. Each rung looks at input signals and turns output signals on or off. The program runs by scanning the ladder logic, testing the input points and the instructions on each rung, and turning the output points on or off.
Generally an optical or laser/camera measuring device. Scanners are composed of a transmitter head and a receiver head, which permit electronics system to obtain the shape and the dimensions an object.
A pressure operated valve which, at its setting, diverts flow to a secondary line while holding a predetermined minimum pressure in the primary line.
A mechanism subjected to the action of a controlling device which will operate as if it were directly actuated by the controlling device, but capable of supplying power output many times that of the controlling device, this power being derived from an external and independent source.
Electro-mechanical device used to control a setworks hydraulic cylinder. An electrical signal is sent to the servo valve which opens, allowing hydraulic fluid to flow into the cylinder. The voltage level and direction of the electrical signal determine the speed and direction of the setworks movement.
The actual position of a setworks is within a certain distance of the command position to which it was sent.
The maximum distance allowed between the actual position of a setworks and the position to which the setworks was sent. When the setworks position is in this range, the setworks is at set complete.
Specific gravity. Also called relative density. As applied to wood, the ratio of the oven-dry weight of a sample to the weight of a volume of water equal to the volume of the sample at a specified moisture content (green, air-dry, or oven-dry).
A measure of the actual mechanical energy per unit time delivered to a turning shaft.
Pulleys mounted on the end of the drive and motor shaft over which belts pass to transfer rotational force from the motor to the shaft.
The growing of tree crops for bioenergy or fiber, characterized by detailed site preparation, usually less than 10 years between harvests, usually fast-growing hybrid trees and intensive management.
A block that can be opened on one side to allow a cable or rope to be laid in the block, instead of threading it through from one end.
Also called relative density. As applied to wood, the ratio of the oven-dry weight of a sample to the weight of a volume of water equal to the volume of the sample at a specified moisture content (green, air-dry, or oven-dry).
A term loosely applied to almost any moving cylindrically shaped part of a hydraulic component which moves to direct flow through the component.
A device for converting energy of high-pressure steam (produced in a boiler) into mechanical power which can then be used to generate electricity.
1. The length of travel of a piston or plunger.
2. To change the displacement of a variable displacement pump or motor.
An auxiliary mounting for a hydraulic component providing a means of connecting piping to the component.
1. To replenish a hydraulic system above atmospheric pressure.
2. To fill an accumulator with fluid under pressure (See Precharge pressure).
Electricity produced by cogeneration equipment in excess of the needs of an associated factory or business.
A stationary canted plate in an axial type piston pump which causes the pistons to reciprocate as the cylinder barrel rotates.
A rotary electromagnetic device generally used as an AC feedback signal generator which indicates position. It can also be used as a reference signal generator.
A device which generates an AC or DC signal proportional to the speed at which it is rotated and the polarity of which is dependent on the direction of rotation of the rotor.
A tangential section is a longitudinal section through a tree perpendicular to a radius. Flat-grain lumber is sawn tangentially.
A heat transfer fluid used instead of steam. They are not interchangeable within the same kiln. Thermal oil is capable of higher temperatures at low operating pressure and is not susceptible to freezing.
Use of heat to chemically change substances from one state to another, e.g. to make useful energy products.
A sensor that measures temperature based on the voltage difference between two dissimilar metals.
Glues and resins that are cured with heat but do not soften when subsequently subjected to high temperatures.
A unit of weight in the metric system equal to 1,000 kilograms or approximately 2,204 pounds. Also called a Metric ton.
1. US unit of weight equal to 2,000 lb; also called a Short ton.
2. British unit of weight equal to 2,240 lb (1,016 kg); also called a Long ton.
Turbines which operate at exhaust pressure considerably higher than atmospheric (noncondensing turbines). These turbines are often multistage types with relatively high efficiency.
A cogeneration system in which electric power is produced first. The reject heat from power production is then used to produce useful process heat.
A type of electromechanical transducer having rotary motion used in the input stages of servo valves.
An element which measures the results at the load and sends a signal back to the amplifier.
A chemical process which reacts an alcohol with the triglycerides contained in vegetable oils and animal fats to produce biodiesel and glycerin.
Traps that discharge condensate at a rate dependent on the position of an internal float. Air is removed through a thermostatic air vent.
Mechanical traps that operate on the difference in the density between steam and water.
Traps that discharge steam at a constant rate and have no internal moving parts to alter or stem its flow.
Traps that use an internal bellows, which expands when steam flows to the trap, closing the orifice. As condensate accumulates the bellows contracts to release it.
A type of furnace in which assembled links of grates are joined together in a perpetual belt arrangement. Fuel is fed in at one end and ash is discharged at the other.
A condition where the fluid particles move in random paths rather than in continuous parallel paths.
The lowest load at which a boiler will operate efficiently as compared to the boiler's maximum design load.
Provides conditioned power and battery backup for computers in the case of a power failure or brownout.
To release flow (usually directly to the reservoir), to prevent pressure being imposed on the system or portion of the system.
A valve which by-passes flow to tank when a set pressure is maintained on its pilot port.
Pressure less than atmospheric pressure. It is usually expresses in inches of mercury (in Hg) as referred to the existing atmospheric pressure.
The speed of flow through a hydraulic line. Expressed in feet per second (fps) or inches per second (ips).
To permit opening of a pressure control valve by opening its pilot port (vent connection) to atmospheric pressure.
A measure of the viscosity-temperature characteristics of a fluid as referred to that of two arbitrary reference fluids.
A boiler grate made up of a tuyere grate surface mounted on a grid of water tubes interconnected with the boiler circulation system for positive cooling. The structure is supported by flexing plates allowing the grid and grate to move in a vibrating action. Ashes are automatically discharged.
Potentially damaging condition in steam pipes where waves develop on the condensate surface within a pipe as steam rushes over it. If the peak of the wave becomes high enough to reach the roof of the pipe, the water in the wave is pushed violently to the far end of the pipe.
Condition of steam coils where condensate is not discharged at a sufficient rate to keep it from accumulating in the coil. Filled with condensate, the coils do not transfer significant heat to the kiln.
A rotating canted plate in an axial type piston pump which pushes the pistons into their bores as it "wobbles".
A solid lignocellulosic material naturally produced in trees and some shrubs, made of up to 40%-50% cellulose, 20%-30% hemicellulose, and 20% -30% lignin.
The application of force over a definite distance. Work (W) = Force (F) x distance (s). Expressed in joules, ergs, and foot-pounds. The joule is exactly the amount of work done in exerting the basic metric unit of force, 1 newton, over the basic metric unit of distance, 1 metre.