泵相關術語解釋英文版

1、泵相關術語解釋英文版A.N.S.I. Standards American National Standards Institute. It consists of a set of specifications (envelope dimensions) for centrifugal pumps manufactured in the United States. Absolute Pressure Absolute pressure is the sum of available atmospheric pressure and the gage pressure in the pump

2、ing system. Absolute Pressure=Atmospheric Pressure + Gauge pressure Affinity laws They predict how capacity, head and horsepower are affected by changes in the centrifugal pump impeller diameter or shaft speed. Air Ingestion Air is coming into the stuffing box because of a negative suction pressure.

3、 Alignment The center line of the pump is perfectly aligned with the centerline of the driver (usually an electric motor). Amperes Law The line integral of the magnetic flux around a closed curve is proportional to the algebraic sum of electric currents flowing through that closed curve; or, in diff

4、erential form, curl B = J. Anti-friction bearing Usually referring to a ball or roller bearing API Gland A seal gland that incorporates a non sparking disaster bushing along with a vent and drain connection (quench), and a flushing connection is known as API Gland. API Specifications API Specificati

5、ons is an acronym for American Petroleum Institute Specifications. API specifications are usually adopted by oil refineries for petroleum applications. Includes seal gland and piping recommendations. Archimedes Principle A floating body displaces its own weight of the liquid in which it floats, and

6、a sunken body has an apparent weight less than its actual weight by the weight of the displaced liquid. Atmospheric Pressure The pressure of the atmosphere on the earth is known as Atmospheric pressure. Atmospheric pressure at sea level is 14.7 PSI. B.E.P. B.E.P. is an acronym for best efficiency po

7、int. It is the point where the power coming out of the pump (water horse power) is the closest to the power coming into the pump (brake horse power) from the driver. This is also the point where there is no radial deflection of the shaft cause by unequal hydraulic forces acting on the impeller. B.H.

8、P. B.H.P. stands for Brake horse power. The actual amount of horsepower being consumed by the pump as measured on a pony brake or dynamometer. Back Plate Black plate is used in some centrifugal pumps to position the stuffing box and provide an impeller wear surface. Back to Back Double Seal The rota

9、ting seal faces are facing in opposite directions. It is the worst possible configuration. In the past this term was used to describe a higher barrier fluid pressure between dual mechanical seals Balance Ratio A 70/30 balance ratio means that 70% of the seal face closing area is seeing the stuffing

10、box pressure and 30% is not seeing the pressure. Balanced seal A design in which the seal face closing area is reduced to lower the closing force, and reduce the heat generation between the faces. Ball bearing It consists of an inner race, an outer race, and a series of balls between them. Often cal

11、led a precision or anti friction bearing. Barrier fluid Barrier fluid is the high pressure fluid that is circulated between two mechanical seals. The fluid should enter the bottom and leave the top to prevent air pockets. Base plate The pump and motor mount on this unit. The pump and motor feet clos

12、est to the coupling should be doweled to the base plate. Bayonet The mechanical seal drive lugs wear into the drive slots and prevent the seal faces from moving forward to compensate for wear. BCS theory A theory put forth to explain both superconductivity and super-fluidity. It suggests that in the

13、 superconducting (or super-fluid) state electrons form Cooper pairs, where two electrons act as a single unit. It takes a nonzero amount of energy to break such pairs, and the imperfections in the superconducting solid (which would normally lead to resistance) are incapable of breaking the pairs, so

14、 no dissipation occurs and there is no resistance. Bellows It can be manufactured from metal or non metallic materials to eliminate flexing, rolling or sliding elastomers in mechanical seal designs. Bellows plate This is a thin, stamped disc. Two are welded together to form a convolution. Bernoullis

15、 Principle The sum of the pressure, kinetic energy density, and potential energy density at any point in an incompressible fluid must be constant. Bio-Savart Law This law describes the contributions to a magnetic field by an electric current. It is analogous to Coulombs law. Mathematically, it is dB

16、 = (mu0 I)/(4 pi r2) dl cross e where dl is the infinitesimal directed length of the electric current causing the magnetic field, I is the current running through that directed length, r is the distance from that directed length, and e is the unit vector directed from the test point to current-produ

17、cing length. Body bound bolts The bolt has an interference fit with the bolt hole. Booster Pump Booster pump is a surface pump used to increase pressure in a water (fluid) line, or to pull from a storage tank and pressurize a water system. Boyles Law The product of the pressure and the volume of an

18、ideal gas at constant temperature is a constant. Brinnell hardness A method of measuring the hardness of metal parts and hard seal faces. Above 350 the standard machining operations of turning, boring, drilling, and tapping become uneconomical. Brownian Motion Brownian motion is continuous random mo

19、tion of solid microscopic particles when suspended in a fluid medium due to the consequence of ongoing bombardment by atoms and molecules. Buffer fluid The low pressure fluid that is circulated between dual mechanical seals is called buffer fluid. Buna N Sometimes it is also called Nitrile. A common

20、 elastomer used in the sealing of oil or water. Sensitive to Ozone attack and therefore has a short shelf life. Bushing A close fitting support device used to restrict flow between two liquids, thermally isolate a hot liquid, support the rotating shaft, break down pressure etc. It is usually made of

21、 carbon or Teflon. Bypass line By pass line is used to re-circulate fluid from the pump discharge to the stuffing box, the stuffing box to the pump suction, or the pump discharge to a lower pressure point in the system. C frame adapter Used to connect and align the pump to the motor with registered

22、fits. (imperial dimensions. Called the D frame adapter in the metric system) C.L.A. C.L.A is acronym for Center line average. Its a method of measuring surface finish in the metric system. We generally use microns as a unit. Canned pump A non seal pump with the shaft, bearings and rotor contained in

23、 a can to prevent product leakage. These pumps are limited to pumping clean lubricating liquids. Capillarity Capillarity is the elevation or depression of the free surface of a liquid in a narrow container, representing equilibrium between wetting, surface tension, and weight. Carbide The compound f

24、ormed when carbon combines with an element. The carbides of metal are very hard and are often used as a mechanical seal face. Carbon bushing Used as a restrictive bushing in flushing applications, a thermal barrier in high temperature applications, a disaster bushing in an A.P.I. gland and to suppor

25、t a deflecting shaft in many mechanical seal applications. Carbon/ graphite A common mechanical seal face material chemically inert to most fluids with the exception of oxidizers, bleaches, halogens and a few other fluids. Carcinogen A cancer producing substance is called Carcinogen. Carnots Theorem

26、 The theorem which states that no engine operating between two temperatures can be more efficient than a reversible engine. Cartridge seal A self contained assembly containing the seal, gland, sleeve, and both stationary and rotating seal faces is known as cartridge seal. Usually needs no installati

27、on measurement. It must be used if impeller adjustments are made. Cartridge seals are the standard for A.P.I. seal applications. Cavitation The vacuum created when the discharge capacity of the pump exceeds the replacement in the suction line. Cavitation occurs when the pump is oversized, when the d

28、iameter of the influent line is too small or when there is an excessively long influent line. Cavitation causes bubbling and vibrations that can damage the pump if they occur over an extended period. Centrifugal Pump The pumping mechanism that spins water in order to push it out by means of centrifu

29、gal force is the mechanism behind centrifugal pumps. Ceramic A hard, chemically inert seal face material that includes products refereed to as silicone carbide. Charles Law The volume of an ideal gas at constant pressure is proportional to the thermodynamic temperature of that gas. Check Valve Check

30、 valve is a valve that allows water to flow one way but not the other. Chemraz This is an elastomer like material manufactured by Green Tweed of England. This is used to seal most solvents and other aggressive fluids. Chloride stress corrosion It occurs in the 300 series of stainless steel. This is

31、caused by a combination of tensile stress, chlorides and heat. No one knows the threshold values. Chrome carbide Forms when chrome forms with carbon in the heat affected zone during the welding of stainless steel. The use of low carbon stainless steel is recommended in these applications Chrome Oxid

32、e The passivated layer that forms on the 300 series of stainless steel is called chrome oxide Close coupled The pump impeller is mounted directly on the motor shaft. There is no separate bearing case. Coated Face A hard coating is plated or welded to a softer base material. Presents problems with di

33、fferent thermal expansion rates, the hard coating can heat check or crack. Not recommended as a seal face material. Composite When used in the content of mechanical seal faces, it refers to either a non metallic material or a combination of non metallic face inserted into a metal holder. Compression

34、 set The elastomer changes shape when it has been exposed to too much heat. Round O-rings come out square. Concentric dual seal One seal is located inside the other, with a common hard face shared by both of them. Because of its large radial space requirement the seal is usually limited to mixer typ

35、e applications. Concentricity When the parts share the same center line they are concentric to each other. Conservation Laws A law which states that, in a closed system, the total qty of something will not increase or decrease, but remain exactly the same; i.e., its rate of change is 0. For physical

36、 qty, it states that something can neither be created nor destroyed. Mathematically, if a scalar X is the qty, then dX/dt = 0, or, equivalently, X = constant. For a vector field F, the conservation law is written as div F = 0; i.e. the vector field F is divergence-free everywhere (i.e., has no sourc

37、es or sinks). Convection A natural circulation of fluid. The hot fluid (lighter) rises and the cool fluid (heavier) sinks. Convection tank This is used to contain fluid between two mechanical seals. An enclosed heater or cooler can be used to control the barrier or buffer fluid temperature. Pressure

38、 or level gages can indicate which seal has failed. Convolution Two metal bellows plates welded or formed together. To count the number of convolutions in a metal bellows you count the spaces between the bellows plates. Cooling jacket It surrounds the stuffing box of the pump to control the temperat

39、ure of the fluid in the stuffing box. Usually it is molded into the back plate. Coulombs law (C. de Coulomb) The primary law for electrostatics, analogous to Newtons law of universal gravitation. It states that the force between two point charges is proportional to the algebraic product of their res

40、pective charges as well as proportional to the inverse square of the distance between them; mathematically, F = 1/(4 pi ?0) (q Q/r2) e, Where q and Q are the strengths of the two charges, r is the distance between the two, and e is a unit vector directed from the test charge to the second. Coupling

41、As the name suggests, coupling is to connect the pump to the driver. It transmits torque and compensates for axial growth, but not for radial misalignment. Critical speed Any object made of an elastic material has a natural period of vibration. When a pump rotor or shaft rotates at any speed corresp

42、onding to its natural frequency, minor unbalances will be magnified. These speeds are called the critical speeds Cryogenic The condition of operation where temperatures are extremely low is called cryogenic process. Cutwater It directs the pumped liquid to the discharge piping. D frame adapter Used

43、to connect and align the pump and motor (manufactured in metric dimensions). The Imperial version is called a C frame adapter. D.I.N. standard It is the German standard for industrial products Daltons Law of partial pressure The total pressure of a mixture of ideal gases is equal to the sum of the p

44、artial pressures of its components; that is, the sum of the pressures that each component would exert if it were present alone and occupied the same volume as the mixture. Damping The physical touching of a component to arrest vibration is called damping. Dead ending Isolating the stuffing box is kn

45、own as dead ending. No recirculation or flushing lines in or out. Deflection Deflection is the movement or displacement of the shaft in a radial direction Density Density is defined as mass of a body divided by volume occupied by the body. The mass density can be calculated by following equation, De

46、nsity = Mass / Volume D-Gun process A metal spray process used to put a hard surface on a softer metal. This is the normal method of applying nickel base tungsten carbide. It is preferred over the popular Plasma Process if you are manufacturing a mechanical seal face. Dial indicator A tool used to m

47、easure concentricity or displacement of a shaft. Diffuser Diffuser is a hosing or vane part that fits around the impeller. The diffuser strips water from the rotating impeller and forces it out the discharge line of the pump, reducing the velocity of water through the pump while increasing the stati

48、c pressure. In some pump models the diffuser and the volute are designed as a single part. Dilatants A liquid that thickens (increases its viscosity) with agitation is called Dilatants Disaster bushing Used in A.P.I. glands to support the shaft in the event of a bearing failure, or to prevent produc

49、t from rushing to atmosphere after a seal failure. The close clearance (0.025 inch or 0.5 mm.) directs most of the leakage through a drain connection in the seal gland to an appropriate container. Discharge recirculation It is connecting a line from the discharge side of the pump to the stuffing box

50、. It should be used with a close fitting bushing in the end of the stuffing box to increase the stuffing box pressure. A common application is when pumping a fluid close to its vapor point DN factor Do not use precision bearings if the bearing bore (millimeters) x rpm. is 300,000 or greater Double b

51、alanced seal Hydraulically balanced in both directions is called double balanced seal. A desirable feature, but seldom provided by seal manufacturers. Double seal An out dated term describing two seals in a pump. The latest terminology is dual seals. In the past the term was used to describe a highe

52、r pressure barrier fluid between dual seals. Double suction pump The rotor is suspended between two bearings with the fluid entering on either side of the impeller. Used at higher capacities Double volute A centrifugal pump design that incorporates two cut waters to prevent shaft deflection when the

53、 pump is operating off of the B.E.P. Lowers the efficiency of the pump and therefore seldom used on smaller size impellers is called double volute. Drag Force Drag force is a non-conservative (dissipative) force which depends on the velocity of the fluid past a surface or the velocity of a body thro

54、ugh the fluid. Drive lugs These lugs or pins transmit the torque from the set screws to the seal face. Dry running Running without fluid at the seal face is called dry running. Dual Seal Two seals running in various configurations: back to back, tandem, face to face, or concentric. Ductility The pro

55、perty of a metal that lets you give it a great deal of mechanical deformation without cracking. Dynamic elastomer The rubber part that has to move to move or flex to compensate for seal face wear or shaft movement. E.P.A. This is an acronym for Environmental protection agency, a government agency wi

56、th a mandate to protect the environment. E.P.R. E.P.R. stands for Ethylene propylene rubber. The most common elastomer used in the sealing of water based and higher pH materials. This cannot be used in petroleum products. Effective diameter In metal bellows terminology it is the calculated diameter

57、where the pressure penetrates between the metal plates. This number is used to determine the hydraulic balance diameter of the seal face. Efficiency Efficiency is the power out of the equipment divided by power in. Elastic range The stressed part retains its memory and returns to its original shape.

58、 Elastomer A rubber like material that, when compressed and then released will return to 90% of its original shape in less than five seconds. Electrolysis A process involving chemical change caused by the passage of an electric current through a liquid is termed as electrolysis. Endurance limit Beyo

59、nd this point the metal will fatigue without increasing the stress. Equation of Continuity Equation of continuity is the mathematical statement that the rate of flow must be the same in all parts of an incompressible fluid, so that the velocity at two different points in the system must be inversely

60、 proportional to the cross-sectional area. Extrusion Extrusion is permanent displacement of a portion of the O-ring into a gap, under the action of fluid pressure. Eye of the impeller The center of the impeller, where the fluid enters is called eye of the impeller. Face combination The materials cho