Pressure drop through pipe
Author: h | 2025-04-25
The fluid flowing through the pipe has a density of 1,000 kg/m and a velocity of 2 m/s. Assuming a friction factor of 0.02, calculate the pressure drop: Pressure Drop In Pipe Pressure Drop Calculation Conclusion. Pressure drop h2x for Pressure Drop Calculations. Calculates the pressure drop through every pipe (CIBSE-verified) Calculates the pressure drop through every valve and fitting (CIBSE-verified)
What is Pressure Drop? Piping Pressure Drop
Piping Systems Equivalent length key pipe components Singularity coefficient key pipe components Partially filled pipe Sonic Velocity Valves types Valves Cv Control valve sizing for gases Pressure safety valves Colebrook correlation Churchill correlation Velocity in pipes Flow regimes Orifice calculations 1. Definition The pressure drop through common fittings and valves found in fluid piping can be calculated thanks to a friction coefficient K. This coefficient must be determined for every fitting. In pre-project, common values are often sufficient. Usual coefficients are given in the tables below. 2. Pressure drop calculation The pressure drop through a fitting or a valve can be calculated thanks to K. Equation 1 : pressure drop through a pipe singularity (valve, fitting...) With ΔPs = pressure drop through pipe singularity (valve, fitting...) (Pa) K = friction coefficient from tables below ρ = fluid density (kg/m3) um = average fluid velocity (m/s) K coefficient in a same pipe section can be added, the pressure drop can then be expressed the following way. Equation 1 : pressure drop through all pipe singularities of a pipe section (valve, fitting...) For compressible fluids, it is important to use the average velocity. If the pressure drop is too important and density and velocity change too much, the pipe section considered must be broken down in smaller sections to keep a good calculation accuracy. 2. K coefficient for additional friction loss due to pipe and fittings The values below are only valid in TURBULENT FLOW Table 1 : K coefficient for calculation of pressure drop through valves and fittings Note : Re>4000 : turbulent regime Source Mecanique et Rheologie des Fluides en Genie Chimique, Midoux, Tec et Docs, 1993, pages 329-331 Perry's Chemical Engineers Handbook, Perry, McGraw Hill, 2008, page 6-18
Pressure drop through an orifice in a pipe - Physics Forums
Technical Information Pressure drop: Pressure drop in pipes is caused by: 1.) Friction 2.) Vertical pipe difference 3.) Changes of kinetic energy Calculation of pressure drop caused by friction in circular pipes First we calculate the Reynolds-Number: If Reynolds number Now we calculate the pipe friction number: Pipe friction number at laminar flow: Pipe friction number at turbulent flow: Now we can calculate pressure drop in circular pipes: Calculation of pressure drop caused by friction in fittings etc. To calculate pressure drop in fittings we use resistance coefficients normally. The resistance coefficients are in the most cases found through practical tests. If the resistance coefficient is known we can calculate the pressure drop: Calculation of pressure drop caused by vertical pipe difference Pressure drop caused by vertical pipe difference we calculate with the formula: Calculation of pressure drop caused by changes of kinetic energy Pressure drop caused by changes of kinetic engergy we calculate with the formula: The element "Dyn. pressure change" calculates these pressure changes. Normally you input the dimension of begin and end of the whole pipe. Pressure drop in gases and vapor Compressible fluids expands caused by pressure drops (friction) and the velocity will increase. Therefore is the pressure drop along the pipe not constant. SF Pressure drop calculates these pressure drops with an approximate equation (pressure drop at arbitrary heat transfer): We set the pipe friction number as a constant and calculate it with the input-data. The temperature, which is used in the equation, is the average of entrance and exit of pipe. You can calculate pressure drops of gases with the same formula as liquids if the relativ change of density is low (change of density/density = 0.02).Pressure Drop in Pipe with Losses (Determine Pressure Drop)
To be used only when necessary.Care should be taken to avoid measuring downstream pressure in the highly turbulent region following the vena contracta. This is why the pipe tap (also known as full-flow tap) standard calls for a downstream tap location eight pipe diameters away from the orifice: to give the flow stream room to stabilize for more consistent pressure readings.Wherever the taps are located, it is vitally important that the tap holes be completely flush with the inside wall of the pipe or flange.Even the smallest recess or burr left from drilling will cause measurement errors, which is why tap holes are best drilled in a controlled manufacturing environment rather that at the installation site where the task will likely be performed by nonexperts.Orifice Plate TapsA photograph of an orifice plate used to measure the flow of natural gas to a large turbine engine is shown here, with a Rosemount model 3051 differential pressure transmitter sensing the pressure drop generated by the orifice:Flange taps are used in this orifice installation, with the taps and pressure transmitter located above the pipe center-line to avoid picking up any liquid droplets that may pass through the pipe.The direction of gas flow in this particular installation is from left to right, making the left-hand pressure tap the “high pressure” side and the right-hand pressure tap the “low pressure” side.As you can see by the pressure gauge’s indication in the photograph, the static line pressure of the natural gas inside the pipe is over 300 PSI. The amount of pressure drop generated by the orifice plate at full flow, however, is likely only a few PSI (100 inches water column is typical for many orifice plate installations).This is why we must use a differential pressure transmitter to measure the orifice plate’s pressure drop: only. The fluid flowing through the pipe has a density of 1,000 kg/m and a velocity of 2 m/s. Assuming a friction factor of 0.02, calculate the pressure drop: Pressure Drop In Pipe Pressure Drop Calculation Conclusion. Pressure drop h2x for Pressure Drop Calculations. Calculates the pressure drop through every pipe (CIBSE-verified) Calculates the pressure drop through every valve and fitting (CIBSE-verified)Pressure Drop Through Pipe Expander - Relief Devices Forum
Calculation of pressure drop in steam and water lines The pressure drop in a water & steam lines refers to the decrease in pressure that occurs as water/steam flows through a pipe or conduit due to factors such as friction and flow resistance. Several factors influence the magnitude of pressure drop in a water line:Pipe Characteristics: The diameter, length, and roughness of the pipe impact the resistance to flow and consequently the pressure drop. Smaller diameter pipes and longer pipe lengths tend to result in higher pressure drops. Additionally, rougher pipe surfaces create more friction and increase pressure drop compared to smoother surfaces.Flow Rate: The rate at which water/steam flows through the pipe affects the pressure drop. Higher flow rates generally result in higher pressure drops due to increased frictional resistance.Fluid Properties: The physical properties of the water/steam being transported, such as viscosity and density, can influence the pressure drop. However, for water at typical temperatures and pressures, these effects are usually negligible. Pipe Fittings and Valves: The presence of fittings, such as elbows, bends, valves, and other obstructions in the water line, can contribute to pressure drop. These components disrupt the flow and introduce additional resistance. It's important to note that pressure drop calculations for steam lines can be complex and require a comprehensive understanding of steam properties and fluid dynamics. Pressure drop in water line:Head loss in water line for turbulent flow is given asHead loss in meter = 4fLV2 / (2gD) Where, f = Friction loss in pipe, generally varies from 0.005 to 0.007L = Pipe lengthD = Diameter of the pipeg = Acceleration due to gravity, 9.81 m/s2V = Velocity of the fluid Example:A Boiler feed pump is delivering feed water flow 50 TPH to the boiler at a distance of 70 meter.The steam drum heightRoughness of pipes - Pressure Drop
Pressure drop is decrease in pressure from one point in a pipe or tube to another point downstream. Pressure drop occurs due to frictional forces acting on a fluid as it flows through the tube. The frictional forces are caused by the resistance to flow. The main determinants of resistance to fluid flow are fluid velocity through the pipe and fluid viscosity. Any liquid or gas will always flow in the direction of least resistance (less pressure). Pressure drop increases proportional to the frictional shear forces within the piping network. A piping network containing a high relative roughness rating as well as many pipe fittings and joints, tube convergence, divergence, turns, surface roughness and other physical properties will affect the pressure drop. High flow velocities and / or high fluid viscosities result in a larger pressure drop across a section of pipe or a valve or elbow. Low velocity will result in lower or no pressure drop. Pressure Drop can be calculated using two values: the Reynolds Number, Re (determining laminar or turbulent flow), and the relative roughness of the piping.Where D is the diameter of the pipe, v is the velocity of the fluid, ρ is the density of the fluid, and μ is the dynamic viscosity of the fluid. The relative roughness of the piping is usually known by cross referencing the Reynolds number with the relative roughness, the friction factor, f, is calculated.The velocity of hydraulic fluid through a conductor (pipe, tube or hose) is dependent on flow rate and cross sectional area. Recommended fluid velocities through pipes and hoses in hydraulic systems are as follows:ServiceVelocity (ft/sec)Velocity (m/sec)Pump suction2-40.6 - 1.2Pump return4 - 131.5 - 4Pump discharge7 - 82 - 5.5Use values at the lower end of the range for lower pressures or where operation is continuous. Refer to the flow/velocity nomograms for more information.Alternatively, fluid velocity can be calculated using the following formula: Q × 0.408v = -------------- D2 Where:v = velocity in feet per second (ft/sec)Q = flow rate in US gallons per minute (US gpm)D = inside diameter of pipe or hose in inchesWhat is Pressure Drop in Pipelines? Manage Pipe Pressure Drops
In a bottle), but become thinner or less viscous when shaken or agitated, returning to their normal state when the source of agitation is removed.In contrast, other products, such as vinegar, act more like Newtonian fluids under processing conditions. Newtonian fluids are liquids which are not thixoprophic, and are not subject to changes in consistency when subjected to shear force. Products which exhibit Newtonian characteristics, therefore, can contribute to a higher pressure drop when being pumped through a pipeline because their consistency does not significantly change as it passes through the process piping system.2. Mechanical Components and Pipe DiameterMechanical components in a piping system—including valves, flow meters, adapters, couplings, and tubing—can also impact pressure drop. Apart from pumps, all of these components commonly found in a process piping system contribute to a system's pressure drop because they remove energy from the process flow rather than adding to it. The mechanical pressure drop also depends on The cross-sectional area of the pipeThe pipe's interior surface roughnessThe length of the pipeHow many bends there are in the systemThe geometrical complexity of each componentFor example, changes in fluid flow or direction (like introducing bends like 45- or 90-degree elbows) can alter the flow, causing more friction and pressure drop. Longer distances traveled mean more chances for friction, reducing efficiency. 3. Changes in the Elevation of PipingA change in elevation in the piping system can also significantly affect pressure drop. Suppose a pipe's starting elevation is lower than its end elevation. In that case, the rise in elevation will cause an additional pressure drop in the system (measured in terms of fluid head, which is equivalent to the rise in elevation). In contrast, the pipe will experience an additional pressure gain if its starting elevation is higher than its end elevation (again, measured in terms of fluid head and equivalent to the fall in elevation in this case).The overall pressure drop may be calculated using several equations for a specific process piping system.Example:P(end)= P(start) - friction loss- fittings loss -component loss + elevation (start-end) + pump headWhereP(end)= pressure at the end of the pipeP(start)= pressure at the start of the pipeElevation (start-end) = (elevation at the start of the pipe) – (elevation at the end of the pipe)Pump head= 0 (if no pump is present)So, when designing a process system to minimize or eliminate pressure drop, process plant engineers should do the following:Ensure that the process pipe's interior diameter and the size of the pump (horsepower, throughput) are properly sized for the type of fluid being piped through the system. Mistakes in either of these can result in excessive pressure drops or overpressure situations.Minimize the number of additional mechanical components (valves, flow meters, adaptors,. The fluid flowing through the pipe has a density of 1,000 kg/m and a velocity of 2 m/s. Assuming a friction factor of 0.02, calculate the pressure drop: Pressure Drop In Pipe Pressure Drop Calculation Conclusion. Pressure dropComments
Piping Systems Equivalent length key pipe components Singularity coefficient key pipe components Partially filled pipe Sonic Velocity Valves types Valves Cv Control valve sizing for gases Pressure safety valves Colebrook correlation Churchill correlation Velocity in pipes Flow regimes Orifice calculations 1. Definition The pressure drop through common fittings and valves found in fluid piping can be calculated thanks to a friction coefficient K. This coefficient must be determined for every fitting. In pre-project, common values are often sufficient. Usual coefficients are given in the tables below. 2. Pressure drop calculation The pressure drop through a fitting or a valve can be calculated thanks to K. Equation 1 : pressure drop through a pipe singularity (valve, fitting...) With ΔPs = pressure drop through pipe singularity (valve, fitting...) (Pa) K = friction coefficient from tables below ρ = fluid density (kg/m3) um = average fluid velocity (m/s) K coefficient in a same pipe section can be added, the pressure drop can then be expressed the following way. Equation 1 : pressure drop through all pipe singularities of a pipe section (valve, fitting...) For compressible fluids, it is important to use the average velocity. If the pressure drop is too important and density and velocity change too much, the pipe section considered must be broken down in smaller sections to keep a good calculation accuracy. 2. K coefficient for additional friction loss due to pipe and fittings The values below are only valid in TURBULENT FLOW Table 1 : K coefficient for calculation of pressure drop through valves and fittings Note : Re>4000 : turbulent regime Source Mecanique et Rheologie des Fluides en Genie Chimique, Midoux, Tec et Docs, 1993, pages 329-331 Perry's Chemical Engineers Handbook, Perry, McGraw Hill, 2008, page 6-18
2025-04-08Technical Information Pressure drop: Pressure drop in pipes is caused by: 1.) Friction 2.) Vertical pipe difference 3.) Changes of kinetic energy Calculation of pressure drop caused by friction in circular pipes First we calculate the Reynolds-Number: If Reynolds number Now we calculate the pipe friction number: Pipe friction number at laminar flow: Pipe friction number at turbulent flow: Now we can calculate pressure drop in circular pipes: Calculation of pressure drop caused by friction in fittings etc. To calculate pressure drop in fittings we use resistance coefficients normally. The resistance coefficients are in the most cases found through practical tests. If the resistance coefficient is known we can calculate the pressure drop: Calculation of pressure drop caused by vertical pipe difference Pressure drop caused by vertical pipe difference we calculate with the formula: Calculation of pressure drop caused by changes of kinetic energy Pressure drop caused by changes of kinetic engergy we calculate with the formula: The element "Dyn. pressure change" calculates these pressure changes. Normally you input the dimension of begin and end of the whole pipe. Pressure drop in gases and vapor Compressible fluids expands caused by pressure drops (friction) and the velocity will increase. Therefore is the pressure drop along the pipe not constant. SF Pressure drop calculates these pressure drops with an approximate equation (pressure drop at arbitrary heat transfer): We set the pipe friction number as a constant and calculate it with the input-data. The temperature, which is used in the equation, is the average of entrance and exit of pipe. You can calculate pressure drops of gases with the same formula as liquids if the relativ change of density is low (change of density/density = 0.02).
2025-03-27Calculation of pressure drop in steam and water lines The pressure drop in a water & steam lines refers to the decrease in pressure that occurs as water/steam flows through a pipe or conduit due to factors such as friction and flow resistance. Several factors influence the magnitude of pressure drop in a water line:Pipe Characteristics: The diameter, length, and roughness of the pipe impact the resistance to flow and consequently the pressure drop. Smaller diameter pipes and longer pipe lengths tend to result in higher pressure drops. Additionally, rougher pipe surfaces create more friction and increase pressure drop compared to smoother surfaces.Flow Rate: The rate at which water/steam flows through the pipe affects the pressure drop. Higher flow rates generally result in higher pressure drops due to increased frictional resistance.Fluid Properties: The physical properties of the water/steam being transported, such as viscosity and density, can influence the pressure drop. However, for water at typical temperatures and pressures, these effects are usually negligible. Pipe Fittings and Valves: The presence of fittings, such as elbows, bends, valves, and other obstructions in the water line, can contribute to pressure drop. These components disrupt the flow and introduce additional resistance. It's important to note that pressure drop calculations for steam lines can be complex and require a comprehensive understanding of steam properties and fluid dynamics. Pressure drop in water line:Head loss in water line for turbulent flow is given asHead loss in meter = 4fLV2 / (2gD) Where, f = Friction loss in pipe, generally varies from 0.005 to 0.007L = Pipe lengthD = Diameter of the pipeg = Acceleration due to gravity, 9.81 m/s2V = Velocity of the fluid Example:A Boiler feed pump is delivering feed water flow 50 TPH to the boiler at a distance of 70 meter.The steam drum height
2025-04-12