Log in. Wiki Pages Latest activity. Media New media New comments Search media. Stove Reviews. Search Everywhere Threads This forum This thread. Search titles only. Search Advanced searchâ€¦. Everywhere Threads This forum This thread. Search Advancedâ€¦. How do you calculate total Head Loss in Parallel Loops? Thread starter Donl Start date Aug 29, JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.

Status Not open for further replies. Donl Feeling the Heat. Nov 23, Ontario. Can anyone explain how to calculate the total head loss in parallel loops? I have been looking for a formula but can't seem to find one. Jul 7, 78 Western MA www. I teach irrigation, which includes friction loss in pipes. When figuring normal friction losses, you take the loss per foot of pipe for the amount of flow in gpm times the number of feet of that size pipe.

I know it doesn't sound totally logical, but it certainly works. As soon as flow begins, even though it may australia ip range that the water flow is shorter in one direction, increased speed in that leg causes increased friction, so the water comes from the other direction.

It does get a bit more complicated when telescoping pipe sizes up or down, but the idea is basically the same. Nov 19, Hampstead,Maryland. If the flow through each loop remains at 2gpm for a total of 6gpm then the head would stay the same I would think. If the total flow is 2gpm divided between the three loops then re figure head at.Log In. Thank you for helping keep Eng-Tips Forums free from inappropriate posts. The Eng-Tips staff will check this out and take appropriate action.

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Are you an Engineering professional? Join Eng-Tips Forums! Join Us! By joining you are opting in to receive e-mail. Promoting, selling, recruiting, coursework and thesis posting is forbidden. Students Click Here. Related Projects. Hello there im trying to work out a pipe equivalent for parallel pipes.

Once I have worked out a single pipe equilivent I can use the Hazen-Williams formula to calculate the head loss for that single pipe. This seems ok Actually it doesn't work if you set the equivalent pipe length to less than the biggest pipe.

If you set it to 1km it states the length is 1. Any tips chaps? The problem is not defined. You don't have a flow term, so all its saying is that there is an infinite combination of equivalent Lengths and diameters that will give you the some head loss at the sum of the flowrates of the two parallel pipes.

And the formula is only true if the flows in each parallel pipe are equal. I changed it for 1 foot of pipe. Thankyou biginch, however im getting confused But what i was after is basically to use the above formula with the dimensions of the "virtual" pipe equivalent of a series of parallel pipes, to get overall head loss.

For each section of parallel pipe i would greate a pipe equivalent, then i would create a single pipe equivalent for all those series of equivalent pipes, if you see what i mean.

But im getting stumped at the first post of "equivalent parallel pipe. Is there any other way i can calculate the pipe equ without having to deal with flow? The reason for this is because i want to calculate the head loss for a range of flows through for a simplified system one virtual pipe equ from a load of parallel pipes that all start and join together at the end. Is this impossible? Don't think so, because without flow there is no head loss.

Then, with resistance known, you could find current, or with current and voltage known, you could determine the value of resistance. If you had the system of equations describing Q for each pipe as a function of HL and could solve them similarly to the electrical method, simultaneously but hydraulics requires an iteration since the equations are nonlinear. But HL depends on D and L and viscosity and pipe roughness Or some combination like that.

I think you might be able to get to the point where you could find the ratio of flow in parallel pipe 1 vs flow in parallel pipe 2, given head loss, but never determine the actual value of either flowHot Threads. Featured Threads. Log in Register. Search titles only. Search Advanced searchâ€¦. Log in. Forums Engineering Materials and Chemical Engineering. JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.

Pressure Loss in Parallel Pipes. Thread starter cruckshank Start date May 12, Hi, I know this is simple but I'd like someone to clarify for me, because my lecturer wasn't clear: Obviously when the pipes are in parallel, the head losses across them are the same.

But what about the total head loss for the parallel pipes as a whole?

### Worked Example 7: Parallel Pipes

I feel like it's the third option, but I'm not entirely sure. Can you tell me which is correct if anyand explain why please. It's 1 except that head loss is a square function of velocity.

But isn't head loss analogous to voltage drop? Parallel resistors have the same voltage drop. What about what I said makes you think I'm saying something that disagrees with that? Well, you're agreeing with 1 which is treating head losses the same as electrical resistances. Is that your contention? Adding a pipe section reduces the head loss just like it reduces the resistance. But it's voltage that is similar to head loss via the formula.

This seems to say that adding a resistor reduces the voltage rather than the resistance. As I said, you didn't give the equations you were comparing to each other, so I interpreted what you were saying, perhaps incorrectly. Yeah, I think if we had a defined system it would be clear. Say two atmospheric tanks, one with a water level 10m below the other.

All parallel pipes between these tanks with submerged entrances and exits would have a head loss of 10m regardless of how many pipes you put in. You must log in or register to reply here.The head loss of a pipe, tube or duct system, is the same as that produced in a straight pipe or duct whose length is equal to the pipes of the original systems plus the sum of the equivalent lengths of all the components in the system.

This can be expressed as. The major head loss for a single pipe or duct can be expressed as:. Since the velocity - v - in equation 2 in general is related to the pipe or duct where the component is located, the sum of the minor losses in a pipe or duct can be expressed as:. The minor loss can be calculated by summarizing the minor loss coefficients - and multiplying the sum with the dynamic pressure head.

The total head loss for a single pipe can be calculated by using equation 1 and 3 :. The total head loss in several serial connected pipes can be calculated by adding the total head loss in each pipe or duct. The total head loss can be expressed as:. Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro.

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Minor Head Loss - head loss or pressure loss - due to components as valves, bends, tees and the like in the pipe or duct system. Tag Search en: major minor head pressure loss drop pipe tube duct systems.

Privacy We don't collect information from our users. Citation This page can be cited as Engineering ToolBox, Modify access date. Scientific Online Calculator. Make Shortcut to Home Screen?The two key expressions are from Section 9 ifirstly that the flow in equals the flow out, so we can say:.

### Calculating head in parellel piped systems

And for pressure continuity at point B, the frictional head loss between A and B in both pipes must be equal, so:. If the flow rate through the supply pipe is 1LPS, what are the flow rates through each parallel pipe and the frictional head loss between points A and B? We know the total flow through the system Q is 1LPS so we can substitute this into the flow equation above:.

We will now choose values of Q 2 and calculate the frictional head loss f h2 for pipe 2 from the friction charts. Using the rearranged flow equation we will calculate the corresponding flow rate in pipe 1 Q 1 and from the friction charts the frictional head loss in pipe 1 f h1. This data is shown below:.

**PARALLEL & SERIES PIPES [FLOW THROUGH PIPES] [FM] HINDI HD**

As both pipes are m long we can plot the two frictional head losses on a graph against the flow rate for Pipe 2 Q 2. The point where the two lines intersect is the flow rate in Pipe 2 when the two frictional head losses are similar.

In this case it is approximately:. And from the graph, the frictional head loss at the point of intersection is approximately:. This site is aimed at providing technical resources and information to assist Appropriate Technology AT specialists working in the following areas: drinking water supply, sanitation, electrical supply, construction, fuel-efficient cooking stoves and environmental education.

ITACA understands AT as technologies that are easy to construct and maintain, low cost, using local resources as far as possible, simple to replicate and adapt to different contexts, and both environmentally and economically sustainable in the long-term. We see AT as a tool to address the inequalities and injustices faced by millions of communities around the world who lack access to the basic resources required for a dignified life.

Any projects making use of information from this website are undertaken at your own risk. The application of Appropriate Technology. Consider the parallel pipes shown in Figure Figure Friction Losses and the Reynolds Number Appendix 4. Welcome This site is aimed at providing technical resources and information to assist Appropriate Technology AT specialists working in the following areas: drinking water supply, sanitation, electrical supply, construction, fuel-efficient cooking stoves and environmental education.

Our Mission ITACA understands AT as technologies that are easy to construct and maintain, low cost, using local resources as far as possible, simple to replicate and adapt to different contexts, and both environmentally and economically sustainable in the long-term. Search This Site. Admin Eng Admin Esp.Hot Threads.

Featured Threads. Log in Register. Search titles only. Search Advanced searchâ€¦. Log in. Forums Engineering Materials and Chemical Engineering. JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.

Pressure Loss in Parallel Pipes. Thread starter cruckshank Start date May 12, Hi, I know this is simple but I'd like someone to clarify for me, because my lecturer wasn't clear: Obviously when the pipes are in parallel, the head losses across them are the same.

But what about the total head loss for the parallel pipes as a whole? I feel like it's the third option, but I'm not entirely sure. Can you tell me which is correct if anyand explain why please. It's 1 except that head loss is a square function of velocity. But isn't head loss analogous to voltage drop? Parallel resistors have the same voltage drop. What about what I said makes you think I'm saying something that disagrees with that?

Well, you're agreeing with 1 which is treating head losses the same as electrical resistances. Is that your contention? Adding a pipe section reduces the head loss just like it reduces the resistance. But it's voltage that is similar to head loss via the formula. This seems to say that adding a resistor reduces the voltage rather than the resistance.

As I said, you didn't give the equations you were comparing to each other, so I interpreted what you were saying, perhaps incorrectly. Yeah, I think if we had a defined system it would be clear.Major Loss: It is calculated by Darcy Weisbach formulas. Loss of head due to friction. For turbulent flow, coefficient of friction.

Mean velocity of flow.

Relation between Coefficient of Friction and Shear Stress. We get.

## Do two pipes in parallel have the same pressure drop as one of those pipes?

Minor Loss: The another type of head loss in minor loss is induced due to following reasons. Loss due to Sudden Enlargement. Head loss. Loss due to Sudden Contraction. Head loss. Remember v 1 is velocity at point which lies in contracted section. Loss of Head at Entrance to Pipe. Loss at Exit from Pipe. Note: In case 1 and 2, flow occurs between pipe to pipe, while in case 3 and 4, flow occurs between tank and pipe. We are taking entry or exit w.

So, be careful.

Combination of Pipes: Pipes may be connected in series, parallel or in both. Let see their combinations. Pipe in Series: As pipes are in series, the discharge through each pipe will be same. If minor loss are neglected then. Pipes in Parallel: In this discharge in main pipe is equal to sum of discharge in each of parallel pipes.

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