This time the old washer shut off valves didn’t break or start leaking, but recently, when I tried to turn them off, the cold water valve was stuck open. I didn’t try to force it to turn, because I’ve had one of the handles break off in my hand and the valve start spraying water (a la last year’s post).

Maximumvelocityinpipeformula

where is: p - pressure; pt - total pressure; pd - dynamic pressure; v - velocity; ρ - density;

Static pressure is pressure of fluid in flow stream. Total pressure is pressure of fluid when it is brought to rest, i.e. velocity is reduced to 0.

New utility sink! I also used this as an opportunity to add a utility sink, which I’ve wanted for years. I loved the sink instantly. It gives me a place to fill and empty the mop bucket, and rinse off and soak big things. It will also serve as a backup to hold washer discharge water if there’s ever a blockage in the drain (which has happened before).

New washer hoses, too. Murphy’s Law dictates that all of my ‘simple’ DIY plumbing projects will expand into a second project. This time it was new washer hoses. As I was reconnecting the washer hoses to the new shutoff, I realized one of the hoses was going bad. Turns out, the cold water hose was so corroded at the washer connection, that it wouldn’t come loose. I feared in removing it, I might also break the connection on the washer itself. I applied some WD40 and stepped away from the project to give it time to work. Success. The hose connection came loose with some gentle coaxing, and without breaking anything else in the process.

Calculatevelocityinpipefrom pressure

This is the expression of law of head conservation to the flow of fluid in a conduit or streamline and is known as Bernoulli equation:

The Darcy equation can be used for both laminar and turbulent flow regime and for any liquid in a pipe. With some restrictions, Darcy equation can be used for gases and vapors. Darcy formula applies when pipe diameter and fluid density is constant and the pipe is relatively straight.

Gasvelocityinpipe Calculator

If dynamic pressure is measured using instruments like Prandtl probe or Pitot tube velocity can be calculated in one point of stream line as:

where is: p - pressure; pt - total pressure; v - velocity; ρ - density;

Most widely accepted and used data for friction factor in Darcy formula is the Moody diagram. On Moody diagram friction factor can be determined based on the value of Reynolds number and relative roughness.

where is: p - pressure; pti - total pressure; v - velocity; M - Mach number; γ - isentropic coefficient;

where is: hL - head loss due to friction in the pipe; f - friction coefficient; L - pipe length; v - velocity; D - internal pipe diameter; g - acceleration of gravity;

Last summer I recommended checking your main water shut off to your house. This summer it’s the washing machine shut offs and hoses.

Velocity of fluid in pipe is not uniform across section area. Therefore a mean velocity is used and it is calculated by the continuity equation for the steady flow as:

WatervelocityinpipeChart

where is: Z1,2 - elevation above reference level; p1,2 - absolute pressure; v1,2 - velocity; ρ1,2 - density; hL - head loss due to friction in the pipe; Hp - pump head; HT - turbine head; g - acceleration of gravity;

This relation can be used to calculate required flow rate of, for example, water heated in the boiler, if the power of boiler is known. In that case temperature difference in above equation is the change of temperature of fluid in front and after the boiler. It should be said that efficiency coefficient should be included in above equation, for precise calculation.

where is: p - pressure; pt - total pressure; pd - dynamic pressure; v - velocity; ρ - density;

Watervelocity Calculator

For compressible flow calculation gas state equation can be used. For ideal gases, velocity for Mach number M < 1 is calculated using following equation:

Fluidvelocity calculator

The nature of flow in pipe, by the work of Osborne Reynolds, is depending on the pipe diameter, the density and viscosity of the flowing fluid and the velocity of the flow. Dimensionless Reynolds number is used, and is combination of these four variables and may be considered to be ratio of dynamic forces of mass flow to the shear stress due to viscosity. Reynolds number is:

Flow in pipes is considered to be laminar if Reynolds number is less than 2320, and turbulent if the Reynolds number is greater than 4000. Between these two values is "critical" zone where the flow can be laminar or turbulent or in the process of change and is mainly unpredictable.

When flow is turbulent and Reynolds number is higher than 4000, the friction factor depends on pipe relative roughness as well as on the Reynolds number. Relative pipe roughness is the roughness of the pipe wall compared to pipe diameter e/D. Since the internal pipe roughness is actually independent of pipe diameter, pipes with smaller pipe diameter will have higher relative roughness than pipes with bigger diameter and therefore pipes with smaller diameters will have higher friction factors than pipes with bigger diameters of the same material.

If you need a quick calculation, but you are not still familiar how to use the calculator, you can order calculation service from the calculator developer.

where is: Z1,2 - elevation above reference level; p1,2 - absolute pressure; v1,2 - velocity; ρ1,2 - density; g - acceleration of gravity

where is: q - flow rate [m3/h]; ρ - density of fluid [kg/m3]; c - specific heat of fluid [kJ/kgK]; Δ T - temperature difference [K]; P - power [kW];

Calculate Reynolds number with this easy to use calculator. Determine if flow is laminar or turbulent. Applicable for liquids and gases.

As in real piping system, losses of energy are existing and energy is being added to or taken from the fluid (using pumps and turbines) these must be included in the Bernoulli equation.

Calculator based on Darcy equation. Calculate pressure drop for known flow rate or calculate flow rate for known pressure drop. Friction factor calculation included. Applicable for laminar and turbulent flow, circular or rectangular duct.

When the velocity is greater than "critical", the regime of flow is turbulent. In turbulent regime of flow there is irregular random motion of fluid particles in directions transverse to the direction on main flow. Velocity change in turbulent flow is more uniform than in laminar.

where is: Δ p - pressure drop due to friction in the pipe; ρ - density; f - friction coefficient; L - pipe length; v - velocity; D - internal pipe diameter; Q - volumetric flow rate;

Calculate heat energy and thermal power for known flow rate. Calculate flow rate for known heat energy or thermal power. Applicable for boilers, heat exchangers, radiators, chillers, air heaters.

where is: f - friction factor; Re - Reynolds number; D - internal pipe diameter; kr - pipe roughness;

It applies to square, rectangular, oval or circular conduit when not flowing with full section. Because of great variety of fluids being handled in modern industrial processes, a single equation which can be used for the flow of any fluid in pipe offers big advantages. That equation is Darcy formula, but one factor - the friction factor has to be determined experimentally. This formula has a wide application in the field of fluid mechanics and is used extensively throughout on this web site.

If the velocity of fluid inside the pipe is small, streamlines will be in straight parallel lines. As the velocity of fluid inside the pipe gradually increase, streamlines will continue to be straight and parallel with the pipe wall until velocity is reached when the streamlines will waver and suddenly break into diffused patterns. The velocity at which this occurs is called "critical velocity". At velocities higher than "critical", the streamlines are dispersed at random throughout the pipe.

Physical values in Darcy formula are very obvious and can be easily obtained when pipe properties are known like D - pipe internal diameter, L - pipe length and when flow rate is known, velocity can be easily calculated using continuity equation. The only value that needs to be determined experimentally is friction factor. For laminar flow regime Re < 2000, friction factor can be calculated, but for turbulent flow regime where is Re > 4000 experimentally obtained results are used. In the critical zone, where is Reynolds number between 2000 and 4000, both laminar and turbulent flow regime might occur, so friction factor is indeterminate and has lower limits for laminar flow, and upper limits based on turbulent flow conditions.

Calculate pipe diameter for known flow rate and velocity. Calculate flow velocity for known pipe diameter and flow rate. Convert from volumetric to mass flow rate. Calculate volumetric flow rate of ideal gas at different conditions of pressure and temperature.

Ah, the mixer. I purchased it in the mid-90s and am so glad I did. I use it almost daily. It doesn’t really belong in that spot in the picture. There shouldn’t be food prep equipment right next to the utility sink, where some gross things will be washed. I’m having to figure out a new place for it in the kitchen. It’s always something….

Flowvelocity calculator for pipe

The mixer’s motor is powerful, and the bowl and beaters are well engineered to mix small or large batches, and for easy cleanup. It’s definitely a classic design; sort of like our generation’s version of our grandmas’ Sunbeam stand mixer. So yeah, I’d say you just got a big future gift hint. 🙂

Bernoulli equation equation is used in several calculators on this site like pressure drop and flow rate calculator, Venturi tube flow rate meter and Venturi effect calculator and orifice plate sizing and flow rate calculator.

The new shut offs. I replaced the washer shut off valves myself, with these Shark-Bite connections, and cpvc pipe. As you know if you’ve done any DIY plumbing projects in recent years, Shark Bite connections are a literal game-changer, making anyone and everyone a potential plumber. They push into place. Honest. No cement, flame torch or solder required; and no leaks.

When calculating Reynolds number for non-circular cross section equivalent diameter (four time hydraulic radius d=4xRh) is used and hydraulic radius can be calculated as:

To express this equation like pressure drop in newtons per square meter (Pascals) substitution of proper units leads to:

When the thickness of laminar sub layer (laminar boundary layer δ) is bigger than the pipe roughness e the flow is called flow in hydraulically smooth pipe and Blasius equation can be used:

Most common equation used for friction coefficient calculation is Colebrook-White formula and it is used for the turbulent flow in the pressure drop calculator:

The regime of flow when velocity is lower than "critical" is called laminar flow (or viscous or streamline flow). At laminar regime of flow the velocity is highest on the pipe axis, and on the wall the velocity is equal to zero.

Velocity calculator for pipemetric

If friction losses are neglected and no energy is added to, or taken from a piping system, the total head, H, which is the sum of the elevation head, the pressure head and the velocity head will be constant for any point of fluid streamline.

where is: δ - boundary layer thickness; D - internal pipe diameter; Re - Reynolds number;

In the turbulent regime of flow, there is always a thin layer of fluid at pipe wall which is moving in laminar flow. That layer is known as the boundary layer or laminar sub-layer. To determine flow regime use Reynolds number calculator.

The pressure drop is the function of internal diameter with the fifth power. With time in service, the interior of the pipe becomes encrusted with dirt, scale and it is often prudent to make allowance for expected diameter changes. Also roughness may be expected to increase with use due to corrosion or incrustation at a rate determined by the pipe material and nature of the fluid.

If the flow is laminar and Reynolds number is smaller than 2000, the friction factor may be determined from the equation:

She loved the sink but her eyes went straight to that mixer right after she commented on how handy it would be. The mixer looks very retro to me for some reason.

where is: D - internal pipe diameter; q - volumetric flow rate; v - velocity; A - pipe cross section area.

where is: D - internal pipe diameter; v - velocity; ρ - density; ν - kinematic viscosity; μ - dynamic viscosity;

Like my former main house shut off valve, the washer shut offs were this round red handled type, that can’t be trusted to last more than a few years.

where is: M - Mach number M=v/c - relation between local fluid and local sound velocity; γ - isentropic coefficient;

I’d wanted the metal braided kind of washer hose, but the store didn’t have that type in the length I needed. I could have ordered and waited on them, but I wanted everything installed that day. These will be good for several years anyway.

Total pressure can be calculated using Bernoulli theorem. Imagining that flow is in one point of stream line stopped without any energy loss Bernoulli theorem can be written as:

Flow in pipe is always creating energy loss due to friction. Energy loss can be measured like static pressure drop in the direction of fluid flow with two gauges. General equation for pressure drop, known as Darcy's formula expressed in meters of fluid is: