Data Sheet
3-Phase, Induction-Type, Electric Motors for Pump Drive
Womack Data Sheet 33: 3-Phase, Induction-Type, Electric Motors for Pump Drive Download Data Sheet 3-PHASE, INDUCTION-TYPE, ELECTRIC MOTORS FOR PUMP DRIVE Design Data Sheet 3 shows how to determine motor HP required to drive a hydraulic pump rated for (so many) GPM at a certain PSI level. Additional information in the present issue covers other […]
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A Load Sensing Control Increases Pump and Circuit Efficiency
Womack Data Sheet 34: A Load Sensing Control Increases Pump and Circuit Efficiency Download Data Sheet A number of pump manufacturers are now coming on the market with variable displacement piston pumps with a load sensing control. We believe this control will become increasingly popular because of its superior performance over a standard pressure compensator […]
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A Study of Rotary-Type Flow Dividers
Womack Data Sheet 31: A Study of Rotary-Type Flow Dividers Download Data Sheet A flow divider accepts a flow of oil under pressure, usually from a hydraulic pump, and divides it into two streams of equal (or unequal) flow volume for operation of two independent branch circuits from one pump, or for synchronization of two […]
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Air Consumption of Cylinders
Womack Data Sheet 58: Air Consumption of Cylinders Download Data Sheet To calculate the HP load to be placed on an air compressor by a reciprocating air cylinder, the power to operate the cylinder with its circuit losses should first be calculated. Then, the additional HP needed for compression losses caused by compressing to too […]
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Angle Problems in Fluid Power Applications
Womack Data Sheet 5: Angle Problems in Fluid Power Applications Download Data Sheet Trigonometric functions such as sines, cosines, and tangents are useful in solving angle problems… for example if the cylinder axis is at an angle to the direction of load movement… in beam and crane problems where the cylinder is not at right […]
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Applications for Cam-Actuated Valves
Womack Data Sheet 44: Applications for Cam-Actuated Valves Download Data Sheet A cam valve (or more properly, a cam-actuated valve) is a directional control valve, and is available for both air and hydraulic operation. For air service, 2-way, 3-way, and 4-way cam valves in sizes up to 1-inch are available. For hydraulics, most cam valves […]
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Applications for Pressure Reducing Valves
Womack Data Sheet 43: Applications for Pressure Reducing Valves Download Data Sheet In hydraulics, a pressure reducing valve serves the same purpose as a “pressure regulator” valve in a compressed air system. It can be described as a 2-way, normally open valve which is piloted from its own outlet. It is one of a variety […]
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Automatic Reversing Circuits for Presses
Womack Data Sheet 13: Automatic Reversing Circuits for Presses Download Data Sheet Circuits on this data sheet are intended for air and hydraulic presses, to automatically retract the press cylinder when a pre-set tonnage has been reached, this retraction to override the operator and take place even though the operator may still be holding down […]
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Better Design of Systems Which Use Fire Resistant Fluids
Womack Data Sheet 37: Better Design of Systems Which Use Fire Resistant Fluids Download Data Sheet Design Problems. Fire resistant fluids are far from being ideal fluids to transmit power from one part of the circuit to another. Nearly always they are used for reasons of safety; they have a far greater ability to resist combustion […]
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Bootstrapping to Save Power – Part 1, Tension Stressing
Womack Data Sheet 36: Bootstrapping to Save Power – Part 1, Tension Stressing Download Data Sheet What is “Bootstrapping”?“Bootstrapping” is a technique which can be applied on certain kinds of applications to save a large amount of input power and to substantially reduce heat accumulation caused by power waste when using more conventional techniques. Bootstrapping […]
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Bootstrapping to Save Power – Part 2, Tension Stressing Continued
Womack Data Sheet 50: Bootstrapping to Save Power – Part 2, Tension Stressing Continued Download Data Sheet The first article in this series on bootstrapping appeared in Design Data Sheet 36. The reader should review that issue for an explanation of the purpose of bootstrapping and the basic operating principle. Diagrams in this issue and in Design […]
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Circuit Design with Vane-Type Rotary Actuators
Womack Data Sheet 65: Circuit Design with Vane-Type Rotary Actuators Download Data Sheet A rotary actuator is an output device for a fluid power system which delivers an oscillating motion (back and forth) over a limited arc. True vane-type actuators are limited to less than l full turn. Other types using gears or rack and […]
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Clamp and Work Applications with Sequence Valves
Womack Data Sheet 19: Clamp and Work Applications with Sequence Valves Download Data Sheet The theme of this issue is clamp and work applications using sequence valves. Clamp and work circuits use at least two cylinders, air or hydraulic. One cylinder advances first and clamps the workpiece in a fixture. Then the other cylinder(s) moves […]
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Computing Power to a Hydraulic System
Womack Data Sheet 64: Computing Power to a Hydraulic System Download Data Sheet Finding the Load ResistanceDesign of the circuit itself has been covered in other Data Sheet issues and in the series of Womack “Industrial Fluid Power” textbooks. In this issue we will deal with cylinder systems and assume the circuit diagram has already been designed. […]
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Cooling an Overheated Hydraulic System
Womack Data Sheet 1: Cooling an Overheated Hydraulic System Download Data Sheet This chart has been prepared for use with an existing hydraulic system which runs at too high a temperature. It may be used to estimate heat exchanger capacity which must be added to reduce the oil temperature to an acceptable level. Before using […]
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Cushioning and Decelerating Methods for Cylinders
Womack Data Sheet 7: Cushioning and Decelerating Methods for Cylinders Download Data Sheet Figure 1 Figure 1 – Preferred Method of Stopping a High Inertia Load in Mid Stroke of a Hydraulic Cylinder.This circuit is designed to absorb high pressure surges caused when a hydraulic cylinder is stopped in mid stroke by centering the 4-way […]
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Cv (Flow Factors) for Compressed Air
Womack Data Sheet 22: Cv (Flow Factors) for Compressed Air Download Data Sheet Design Data Sheet No. 17 showed charts for sizing hydraulic valves by using Cv (flow factor) ratings. The chart below gives the same information for compressed air. Sheet 17 should be reviewed for an explanation of Cv factor and other general information. The […]
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Cylinder Drift Problems and Their Solution
Womack Data Sheet 54: Cylinder Drift Problems and Their Solution Download Data Sheet There are certain conditions in a hydraulic cylinder circuit which may cause a cylinder to slowly drift (creep) when its 4-way control valve is in its center neutral position. The cause (in the fluid circuit) for cylinder drift is the unbalance between […]
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Cylinder Force for Punching, Notching and Shearing
Womack Data Sheet 12: Cylinder Force for Punching, Notching and Shearing Download Data Sheet Table of Materials – See handbook for othersSheet MaterialShear Str. Range, PSIMultiplierAluminum8,000 to 34,000.13 to .57Brass, half-hard28,000 to 48,000.47 to .80Dural22,000 to 83,000.37 to 1.4Copper, rolled22,000 to 29,000.37 to .48Steel, low carbon45,000 to 75,000.75 to 1.3Steel, medium carbon60,000 to 135,0001.0 to […]
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Design of Cams for Actuating Limit Switches
Womack Data Sheet 8: Design of Cams for Actuating Limit Switches Download Data Sheet (Some of the material on switch cams was adapted from information published by R.B.Denison, Inc.) Too often there is a lack of attention given to properly actuating a limit switch. The designer may be under the mistaken impression that the size, […]
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Designing Slow Feed Circuits – Part 1, Hydraulic Cylinders
Womack Data Sheet 28: Designing Slow Feed Circuits – Part 1, Hydraulic Cylinders Download Data Sheet The ProblemAlthough the accuracy of oil metering and the speed regulation may be quite satisfactory at moderate to high feed rates, they become progressively worse as cylinder speed is reduced by metering the oil flow through a flow control […]
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Designing Slow Feed Circuits – Part 2, Air Cylinders
Womack Data Sheet 38: Designing Slow Feed Circuits – Part 2, Air Cylinders Download Data Sheet Part 1 of this series, covering hydraulic cylinders, is in Design Data Sheet 28. The purpose of the present issue is to suggest circuit arrangements which will minimize the tendency of an air cylinder to “chatter” or move erratically when […]
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Dimensions of SAE Port Pads
Womack Data Sheet 59: Dimensions of SAE Port Pads Download Data Sheet Information on SAE port pads was obtained primarily from SAE J518 specification. For additional dimensions, that source may be consulted. Figure 1. Many hydraulic components, particularly those of large size and those operating at high pressure, are manufactured with SAE 4-bolt port pads with […]
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Effects of Oversizing or Undersizing an Electric Motor for a Job
Womack Data Sheet 49: Effects of Oversizing or Undersizing an Electric Motor for a Job Download Data Sheet Motor information given here pertains only to 3-phase squirrel cage induction motors, Design B, the type used most often to drive hydraulic pumps. Our suggestions for limits on overloading electric motors were given in Data Sheet 2. Information […]
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Electric Motor Size for Hydraulic Pump Drive
Womack Data Sheet 3: Electric Motor Size for Hydraulic Pump Drive Download Data Sheet Figures in the body of this table show the horsepower needed to drive a positive displacement hydraulic pump, and would be valid either for electric motor or engine drive. The table was calculated from the formula: HP = PSI x GPM ÷ […]
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Factors which Influence the Speed of an Air Cylinder
Womack Data Sheet 14: Factors which Influence the Speed of an Air Cylinder Download Data Sheet This subject will be covered in two parts: (1), those factors to be considered when first designing the system and selecting cylinder bore diameter and, (2), changes which can be made in an existing system to increase cylinder speed. […]
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Finding the Cause of Solenoid Coil Burn-Out
Womack Data Sheet 30: Finding the Cause of Solenoid Coil Burn-Out Download Data Sheet Perhaps occasionally a coil on a solenoid valve may burn out because of a defect in its manufacture. But usually the cause can be traced to some abnormal condition either in operating conditions of the machine on which the valve is […]
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Flow Through Orifices
Womack Data Sheet 9: Flow Through Orifices Download Data Sheet Hydraulic Oil Flow through Orifices The chart shows approximate pressure drops which may be expected at various flows rates through sharp edge orifices for petroleum type hydraulic oil. It may be used for designing limiting flow orifices in hydraulic systems. Chart values must be considered […]
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Fluid Power Equivalent of Mechanical Horsepower
Womack Data Sheet 27: Fluid Power Equivalent of Mechanical Horsepower Download Data Sheet The HP flowing in the piping of a fluid power system is proportional to both pressure and rate of flow. Power can only be transmitted if the fluid is moving under pressure. The HP level determines not only how much load can […]
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Force Required to Accelerate a Load
Womack Data Sheet 4: Force Required to Accelerate a Load Download Data Sheet The load on a hydraulic cylinder (or motor) consists of these three components: (1). Normal load resistance, where fluid power is converted into mechanical work exerted against the load. (2). Friction resistance, where some of the fluid power is expended in overcoming […]
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Hoisting and Cable Tensioning with Cylinders
Womack Data Sheet 6: Hoisting and Cable Tensioning with Cylinders Download Data Sheet Hoisting with Cylinders Figure 1 – Direct PullWhen used in a direct pull, with one cable supporting the load, the ratio between load lift height and cylinder stroke is 1:1. In this example, to raise a 1000 lb. weight a height of […]
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Horsepower Required for Compressing Air
Womack Data Sheet 72: Horsepower Required for Compressing Air Download Data Sheet This 3-part table shows the horsepower required to compress 1 SCFM (standard cubic foot per minute} of air from atmospheric pressure (0 PSIG} to the pressures shown in the table. Values are shown for single-stage, two-stage, and three- stage piston-type air compressors operating […]
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How to Calculate Stretch in Cylinder Tie Rods
Womack Data Sheet 16: How to Calculate Stretch in Cylinder Tie Rods Download Data Sheet The amount of stretch (elongation) in mechanical members under tension is very easy to calculate with a simple formula. The method described on this sheet can be applied to any structural member subjected to stress. In fluid power design, it […]
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How to Control Air Motors
Womack Data Sheet 40: How to Control Air Motors Download Data Sheet Background Information. The fluid power user should not overlook the advantages of air motors on certain applications where they may perform better than either electric motors or hydraulic motors. They will work in hostile environments such as extreme heat or cold, in corrosive, flammable, […]
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How to Make Noise Calculations with Decibels
Womack Data Sheet 35: How to Make Noise Calculations with Decibels Download Data Sheet Information in this issue supplements the basic information on noise levels in Design Data Sheet 24. The purpose here is to define more clearly how decibels are used to rate noise of hydraulic pumps, and to give examples of calculations. Comparing Sound […]
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How to Select a Pressure Switch for Your Application
Womack Data Sheet 20: How to Select a Pressure Switch for Your Application Download Data Sheet Part of the information on diaphragm and bourdon tube pressure switches was adapted from information published by the Barksdale Division of Delaval. Several types of pressure switches are available. The designer should choose a type which can be expected […]
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How to Solve Your Air Line Water Problem
Womack Data Sheet 45: How to Solve Your Air Line Water Problem Download Data Sheet Certain applications like those pictured below, and others, will not tolerate any water whatsoever condensed out of the air line. One of several methods may be used to eliminate the water problem. But to better understand the solutions proposed here, […]
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How to Use Flow Coefficients (Cv) for Hydraulic Fluids
Womack Data Sheet 17: How to Use Flow Coefficients (Cv) for Hydraulic Fluids Download Data Sheet In case you have forgotten now-to-use the Cv flow coefficient (flow factor) for selecting valve size, this data sheet will review the use of Cv coefficients for hydraulic fluids. Cv information for compressed air is in Data Sheet 22. Some […]
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How to Use Pressure Differential Sequencing
Womack Data Sheet 15: How to Use Pressure Differential Sequencing Download Data Sheet Sequencing circuits are those that automatically program two or more cylinders on a machine to cause them to extend and retract in a predetermined sequential order on every cycle. While sequencing may be accomplished in several ways, the problem to be discussed […]
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Hydraulic Cylinder Speeds – Extension and Retraction
Womack Data Sheet 77: Hydraulic Cylinder Speeds – Extension and Retraction Download Data Sheet Lines in bold type show cylinder piston extension speeds in “Inches per Minute”. Lines in italic type show piston retraction speeds in “Inches per Minute” with various size piston rods. The smallest diameter rod for each bore is the standard size […]
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Hydraulic Filter Beta Ratings and the Multi-Pass Test
Womack Data Sheet 61: Hydraulic Filter Beta Ratings and the Multi-Pass Test Download Data Sheet During the last few years a considerable amount of work has gone into filter research. For one thing, a test has been devised, called a “multi-pass” test for a more realistic rating for hydraulic filters. The “beta ratio” (β) derived […]
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Information on Sound Power and Sound Pressure
Womack Data Sheet 24: Information on Sound Power and Sound Pressure Download Data Sheet The Nature of SoundAirborne sound (including noise) is a variation in PSI air pressure in the audible range, and sound pressure can be measured by its force against the diaphragm of a microphone. Sound waves, unlike light waves, are longitudinal vibrations […]
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Interchange Between SI, Metric and U.S. Customary Units
Womack Data Sheet 25: Interchange Between SI, Metric and U.S. Customary Units Download Data Sheet International Standard (SI) units are shown in the first column of each chart. Values with exponents can be handled directly on a pocket calculator which has exponent key. For manual calculations, remember that the + or – sign in front […]
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ISO Pipe Thread and Port Thread Sizes
Womack Data Sheet 79: ISO Pipe Thread and Port Thread Sizes Download Data Sheet Pipe Threads. These metric pipe thread sizes have been adopted by the ISO (International Standards Organization), and are primarily intended for pipes or tubes for screwing together or into ISO pipe ports on valves, cylinders, pumps, and other components. An appropriate thread […]
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JIC Standard Symbols for Electrical Ladder Diagrams
Womack Data Sheet 80: JIC Standard Symbols for Electrical Ladder Diagrams Download Data Sheet These graphic symbols are the ones used most often on ladder diagrams for fluid power electrical control circuits. They are standard JIC (Joint Industrial Council) symbols as approved and adopted by the NMTBA (National Machine Tool Builders Association). They have been […]
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Life Expectancy of Piston-Type Pumps and Motors
Womack Data Sheet 29: Life Expectancy of Piston-Type Pumps and Motors Download Data Sheet Information in this issue applies only to piston-type hydraulic pumps and motors. Additional information on gear and vane-type pumps and motors will be presented in a later issue. Most of the information applies to both pumps and hydraulic motors, but for […]
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Matching a Hydraulic Motor to the Load
Womack Data Sheet 42: Matching a Hydraulic Motor to the Load Download Data Sheet On the design of a new machine which is to be run with a hydraulic motor, a determination of required speed and horsepower must be made so a model with suitable ratings can be selected. This issue describes several methods of […]
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Matching the Size of a Broken Pump or Motor
Womack Data Sheet 2: Matching the Size of a Broken Pump or Motor Download Data Sheet When replacing a pump, catalog ratings will usually be shown in GPM at a specified shaft speed. On motors, catalog ratings will usually be shown as C.I.R. (cubic inches displacement per shaft revolution). Formula are shown for calculating either […]
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Minimizing Shock in Hydraulic Systems
Womack Data Sheet 23: Minimizing Shock in Hydraulic Systems Download Data Sheet Momentary high pressure surges passing through the fluid in a hydraulic system generate noise and may cause hoses to jump and tubing to vibrate. Needless to say, these pressure spikes are a strain on a system and should be eliminated in so far […]
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NEMA Frame Assignments – 3-Phase Induction Motors
Womack Data Sheet 66: NEMA Frame Assignments – 3-Phase Induction Motors Download Data Sheet The most widely used type of electric motor for driving a hydraulic pump is the 3-phase, squirrel cage induction motor, with Design B electrical characteristics. It is available in open drip-proof, totally enclosed, and explosion proof frames. Information in this issue […]
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NFPA Mounting Flanges and Shafts for Hydraulic Pumps and Motors
Womack Data Sheet 76: NFPA Mounting Flanges and Shafts for Hydraulic Pumps and Motors Download Data Sheet For many years the only standardization on pump and motor shafts and mounting flanges had been the SAE (Society of Automotive Engineers) Standard J744a. It was widely accepted by other industries as well as the automotive and is […]
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Piston-Type Pressure Intensifiers
Womack Data Sheet 69: Piston-Type Pressure Intensifiers Download Data Sheet Pressure intensifiers are devices which can deliver a small flow of oil (or air) at an unusually high pressure. They offer an economical means of producing high pressure for applications where very little flow is required. The most popular type of intensifier – the piston […]
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Pressure Compensated Hydraulic Pumps
Womack Data Sheet 62: Pressure Compensated Hydraulic Pumps Download Data Sheet A pressure compensator is a device built into some pumps for the purpose of automatically reducing (or stopping) pump flow if system pressure sensed on the pump outlet port, should rise above a pre-set desired maximum pressure (sometimes called the “firing” pressure). The compensator […]
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Pressure Compensated Hydraulic Speed Control – Part 1
Womack Data Sheet 39: Pressure Compensated Hydraulic Speed Control – Part 1 Download Data Sheet Pressure Compensated Flow Control Valves. These are adjustable speed control valves for hydraulic cylinders and motors. In addition to the adjustable metering orifice, there is a “compensating” spool which can modulate the flow during operation to keep it constant at the […]
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Pressure Loss Due to Fluid Flow Through Pipes
Womack Data Sheet 57: Pressure Loss Due to Fluid Flow Through Pipes Download Data Sheet This table has been calculated from a formula published by the Crane Co. on pages 3-12 of Technical Paper 410. It shows the approximate pressure loss per 100 feet of Schedule 40 pipe with hydraulic oil of known specific gravity […]
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Pressure Rating of Steel Cylinder Tubing
Womack Data Sheet 32: Pressure Rating of Steel Cylinder Tubing Download Data Sheet The chart on this page shows the fluid pressure rating of mild steel tubing used for cylinder barrels. Tubing inside diameter (bore) is shown in the first column, and wall thickness along the top of the chart. The chart includes an ample […]
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Pump-Down Time for Vacuum Tanks
Womack Data Sheet 60: Pump-Down Time for Vacuum Tanks Download Data Sheet When evacuating a tank, the approximate running time of the vacuum pump to reach the desired degree of vacuum can be estimated from this chart, either starting from atmospheric pressure or starting from a lower vacuum and pumping to a higher level. The […]
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Rotary-Type Pressure Intensifiers
Womack Data Sheet 70: Rotary-Type Pressure Intensifiers Download Data Sheet A pressure intensifier is a device which accepts a flow of oil (or other fluid) at a relatively low pressure and converts it to a higher pressure. The rate of flow is reduced in the same proportion that the pressure is amplified. It is a […]
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Selection Guide for Electric Wire Size
Womack Data Sheet 11: Selection Guide for Electric Wire Size Download Data Sheet Two Factors to be Considered When choosing the conductor size for electrical wiring, there are TWO important factors which must be considered, and these are: (1), the safe current-carrying capacity without overheating, and (2), keeping the voltage loss to an acceptable minimum. […]
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Simple Measurements in Hydraulic Systems
Womack Data Sheet 55: Simple Measurements in Hydraulic Systems Download Data Sheet Easy ways of making some simple tests on hydraulic systems are briefly described in this issue. Some of these tests have been described in greater detail in previous issues. Please request any of these back issues which you do not have. Figure 1. Suggested […]
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Speed Regulation of Hydraulic Motors – Part 1
Womack Data Sheet 51: Speed Regulation of Hydraulic Motors – Part 1 Download Data Sheet Speed regulation must not be confused with speed control of a hydraulic motor. Speed regulation refers to the undesirable slow down of the motor when it picks up a load. It is an indicator of how well the motor will […]
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Speed Regulation of Hydraulic Motors – Part 2
Womack Data Sheet 52: Speed Regulation of Hydraulic Motors – Part 2 Download Data Sheet In this issue we will continue our study of how speed regulation of a hydraulic motor circuit is a direct measure of the range over which its speed can be varied with acceptable performance. Internal slippage of the motor itself […]
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Spool-Type Proportional Flow Dividers
Womack Data Sheet 26: Spool-Type Proportional Flow Dividers Download Data Sheet Flow dividers – are devices which split the flow from a pump into two streams for independently operating two branch circuits. Advantages of flow divider operation are: Two general methods are used for dividing a flow of oil. One method uses a sliding spool; […]
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Steel Tubing – Pressure and Flow Ratings for Hydraulic Plumbing
Womack Data Sheet 73: Steel Tubing – Pressure and Flow Ratings for Hydraulic Plumbing Download Data Sheet Pressure ratings are for annealed steel tubing “hydraulic grade” having a tensile strength of 55,000 PSI (the kind most often used for plumbing hydraulic systems). See notes on back for adjustment to other steels. Pressure ratings are shown […]
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Tips on Selection of Plumbing Size for Hydraulic Systems
Womack Data Sheet 56: Tips on Selection of Plumbing Size for Hydraulic Systems Download Data Sheet There is an optimum size for the piping in each line of a hydraulic system. It must be large enough to carry the oil flow with an acceptable pressure loss, but should be no larger than necessary. Undersize piping […]
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Tips on Selection of Shell and Tube Heat Exchangers
Womack Data Sheet 46: Tips on Selection of Shell and Tube Heat Exchangers Download Data Sheet The reader may want to refer to Design Data Sheet #1 for formula relating to heat transfer and for additional information on heat exchanger selection. Information in this issue relates only to industrial hydraulic systems using mineral base oil and using […]
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Tips on Sizing Accumulators
Womack Data Sheet 47: Tips on Sizing Accumulators Download Data Sheet Space does not permit a full discussion of accumulators, and this issue will be limited to a practical method of determining the minimum capacity of an accumulator when used to supplement the flow of oil from a pump as in the circuit shown below. […]
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Troubleshooting for Recurrent Solenoid Burn Out
Womack Data Sheet 18: Troubleshooting for Recurrent Solenoid Burn Out Download Data Sheet This sheet describes an easy-to-assemble test device to help diagnose the cause of repeated burn out of a solenoid coil on a double solenoid air or hydraulic valve. One possible cause for recurrent burn out is the energizing of both solenoids at […]
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Troubleshooting Tips for Closed Loop Hydrostatic Systems
Womack Data Sheet 67: Troubleshooting Tips for Closed Loop Hydrostatic Systems Download Data Sheet In this and future issues of these Design Data Sheets we will present information which we hope will be helpful to a service man in the field who is faced with the problem of finding the cause of a breakdown in […]
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Troubleshooting Tips for Hydraulic Pumps
Womack Data Sheet 48: Troubleshooting Tips for Hydraulic Pumps Download Data Sheet The pump is probably the component most subject to wear in a hydraulic system, and the one most likely to cause a sudden or gradual failure in the system. Pump trouble is usually characterized by increased noise, increased heat, erratic operation of cylinders, […]
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Troubleshooting Tips for Hydraulic Systems
Womack Data Sheet 63: Troubleshooting Tips for Hydraulic Systems Download Data Sheet This data sheet describes a step-by-step check-out procedure for hydraulic systems which have previously been working satisfactorily but which have developed trouble, usually over a 24-hour working period, which renders them inoperative. It is not intended as a diagnostic check of new systems […]
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Troubleshooting Tips for Open Loop Hydraulic Systems
Womack Data Sheet 68: Troubleshooting Tips for Open Loop Hydraulic Systems
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Two-Hand Safety Control of Air and Hydraulic Circuits
Womack Data Sheet 10: Two-Hand Safety Control of Air and Hydraulic Circuits Download Data Sheet Where cylinders are operating mechanisms which might present a safety hazard to the operator, dual controls may be provided. These require the use of both hands to start the cylinder and to keep it in motion. Dual controls are also […]
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U.S. Customary Units Compared to ISO International Standard Units
Womack Data Sheet 21: U.S. Customary Units Compared to ISO International Standard Units Download Data Sheet Preliminary work was started on an international system of units prior to 1954, and some European countries have adopted their own version of a metric system which could be used internationally. However, there are many duplicate metric units which […]
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Vehicle Drive with Hydraulic Motors – Part 1
Womack Data Sheet 41: Vehicle Drive with Hydraulic Motors – Part 1 Download Data Sheet Wheel Motors. Figure 1. Several manufacturers produce hydraulic motors designed especially for wheel drive of a vehicle. Since these motors must carry a part of the vehicle weight as side load on the shaft, the mounting flange is located a short […]
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Vehicle Drive with Hydraulic Motors – Part 2
Womack Data Sheet 71: Vehicle Drive with Hydraulic Motors – Part 2 Download Data Sheet Please refer to Part 1 of this series which appeared in Design Data Sheet 41. We are primarily concerned with hydraulic motor drive of off-the-road vehicles, but the data in these sheets are also applicable for direct engine drive. This is […]
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Wire Size and Fuse Ratings for 3-Phase Induction Motors
Womack Data Sheet 78: Wire Size and Fuse Ratings for 3-Phase Induction Motors Download Data Sheet Motors are usually protected by both fuses (or circuit breakers) and by heater coils in a magnetic starter. Fuses open the circuit quickly in case of a massive overload or short circuit. Heater coils provide a delay and open […]
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Working with ISO Metric Cylinders – Part 1
Womack Data Sheet 74: Working with ISO Metric Cylinders – Part 1 Download Data Sheet Sometime in the future, cylinders and other fluid power components will be built to ISO (International Standards Organization) dimensions in which metric measurements are used. Conversion to international standards has been slow in the United States, and at the time […]
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Working with SI (System International) Cylinders – Part 2
Womack Data Sheet 75: Working with SI (System International) Cylinders – Part 2 Download Data Sheet Piston Velocity – Metric Hydraulic Cylinders – For Pump Flows of 3 to 75 Liters per Minute PistonDiametermm. RodDiametermm. 3l/min. 5l/min. 10l/min. 15l/min. 20l/min 25l/min. 30l/min. 40l/min. 50l/min. 75l/min. 25 None* 6.111 10.19 20.37 – – – – – […]