# Questions tagged [pipelines]

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11 views

### Calculating the elevation of pipe invert

Do I take cuts and fills into account when calculating pipe invert depth? What would be the math on that?
• 1
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### Quantitative Risk Assessment Of Onshore Crude Oil Pipelines

I am currently working on a project that requires a quantitative risk assessment of a potential release (analysis of frequency and consequences) onshore pipelines transporting crude oil (underground). ...
32 views

### Heat convenction through double pipe

I have a realistic scenario which involves a double contained PP plastic pipe which a section of the pipeline is placed outdoor. What I want to determine if insulation is required at all. The media is ...
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### Is there any difference in performance when using a small pipe diameter for a greens bubbler?

So a greens bubbler is a setup that helps the farmer cleaning greens/ gets/ fruits by agitating the water. Details here: https://blog.uvm.edu/cwcallah/2021/10/06/building-a-better-greens-bubbler/. In ...
55 views

### Where should I restrict the flow of a pump?

I am using a 1/2 hp sump pump to provide flood coolant to a CNC milling machine. The sump pump has a 1.5" outlet. The milling machine already has a 1/2" adapter and manifold which connect to ...
• 113
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### How to determine the slope for the gravity flow of highly viscous fluids (eg. gum)?

I am looking for a method to determine the slope of the pipe required to maintain a gravity flow for highly viscous fluid. The Hazen-Williams equation for gravity flow is applicable for liquids which ...
53 views

### Computing the velocity of water under reverse flow conditions from storm water drain

I am trying to compute the approximate velocity of water during reverse flow from the outfall location to the street through storm inlets. This is generally seen during what is commonly referred to as ...
267 views

### How to calculate mass flow rate at the Multiple Channel Outlets?

I have a basic question regarding the calculation of mass flow rates of a channel with multiple outlets. In the scenario depicted in the image below, we have a single inlet with a mass flow rate (m1) ...
1 vote
94 views

### Fluid dyanmic - flow in a pipe

Dear fellow engineers, I have a question regarding a fluid dynamic problem which I have sketched out. The initial fluid velocity is 1.5 m/s at 1.5 bar and the fluid is water. The pipe line has a ...
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### How to estimate the amount of fuel leakage on a pressurized pipeline

I need to identify the amount of leakage into the machinery space, as during an incident, the engineer started internal fuel transfer from a cargo tank to the fuel daily service tank. The fuel pump ...
1 vote
28 views

### Suitable pipe suggestion required

I've got a machine that sucks water. The inlet is half inch. I had been using braided pvc till now but it has started to breathe air which is causing problems with the machine. It also bends under ...
30 views

### "reversing pump" in closed water circuit, can water pumped reach further than wave length?

In a closed water circuit with a reversing pump. If the wavelength of how far water pressure wave (positive and negative) reaches during one pump/suction cycle is much shorter than the length of the ...
200 views

### Is it possible to determine how far a vacuum cleaner hose can suck an object in from?

I'm working on a project similar to a vacuum cleaner, where I have a suction pump connected to an open ended pipe that has a negative pressure gradient such that things are being sucked into it with a ...
48 views

### Heat transfer in open equalization tank

I have to cool waste water in equalization tank (open tank) from 60 C to 30 C. Here is the information about the waste water: [![enter image description here][1]][1] [1]: https://i.sstatic.net/QqiSG....
56 views

### Sharp Edged Pipe with Negative Pressure

I want to calculate the 2D pipe flow with sharp edged contraction pipe (below figure). The fluid is water, the model is steady state k-epsilon. The boundary condition is velocity inlet (8.47ft/s = 2....
1 vote
109 views

### How to transfer high pressure hydrogen using flexible pipes?

The task is to transfer hydrogen (high pressure gas > 400 bars) from offshore platform to land. To do so we have to use flexible pipes but for high pressure and high flow rate I'm afraid we can't ...
303 views

### Flow through Pipe annulus with pressure controlled opening

I have a pipe with radius $R_1$ with a smaller pipe within (radius $R_2$). I want to find an expression for the flow through the pipe which flows in the annulus area. However, the known values are the ...
• 61
81 views

### Calculate pipe size and friction loss for an agricultural project's water system?

I'm in the process of designing a water system for our regenerative agricultural project in the Horn of Africa. I'm looking to install a ≈1000L water tank on a 3 meter stand which will gravity supply ...
41 views

### How to determine the efficacy and potential energy of hydro power energy storage?

The project I'm thinking about building a cheap DIY hydro energy storage (like a battery) system. I can build it but so far I can't really figure out the calculations to validate my idea and where to ...
• 123
158 views

### How can a thicker pipe withstand more pressure? (In general how does geometry affect stress)

I'm misunderstanding something about how geometry affects yield stress. I think this example best illustrates my confusion: Say you have two pipes with the same internal diameter, same material grade, ...
• 121
93 views

### Minor loss coefficient for pipe end

I want to estimate the head loss in a piping system. However, I don't know how to find or determine the loss coefficient for a connection point within the system. At one point the pipe ends in a ...
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1 vote
64 views

### Pipe size selection for seawater circulation system

I am trying to get the right pipe size for seawater circulation system aboard a ship. The water is used to keep oysters alive while transporting them. The system has 8 Ebara SQPB 100 pumps. The ...
92 views

### How to reduce a welded iron pipe without bending it?

I would like to reduce the diameter of an iron (welded) pipe without bending to the side, where the weld is. With the usual procedure, the result is as follows: I am using the usual pipe reducing ...
46 views

### How are the undersea gas pipelines repaired?

This question is related to the recently damaged Nord Stream, but this is not a political question, poorly technical. I would like to ask if there are any known ways to restore the undersea pipeline ...
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1 vote
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### If you shut down a gas pipeline for a few months would you fill it with gas at full pressure?

This is of course inspired by the Nordstream gas pipelines in the Baltic Sea. When it was decided that Nordstream 2 would not start operating after construction finished they still filled it with ...
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1 vote
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### Why don't we light the methane escaping from the NordStream pipeline?

The methane escaping from the NordStream pipeline for a few days now has a much more potent greenhouse effect than carbon dioxide. Burning methane gives us CO2. The pipe won't be repaired before all ...
• 111
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### How to determine of pumps required on a pipeline

I have a 14km long pipe with total head loss of 113m, transporting water at 40m3/h. How do I decide how many pumps I need? I understand headloss is 113m, but I still don't get how does this tells me ...
51 views

### Plug valve problem

A pig is a solid plug that is introduced into the pipeline to be serviced. Fluid is pumped upstream of the pig to provide the necessary force to set the device in motion, and to perform the desired ...
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### Choosing the right pipes for a combination of peristaltic and circulation pump

I would like to circulate the water within an aquarium that contains around 30l water with a circulation pump and an active chiller that contains R134a cooling fluid. New water shall be sucked with a ...
35 views

### How to draw a pipe being moved between tanks? (ISO standard P&ID)

Where I work, we have a set-up that functionally, works as represented below: I represented it as such, due to a lack of know-how in regards to the actual, ISO-standardized way of representing this ...
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828 views

### Direction of fluid flow

Consider water flowing in a pipe, and I don't know the direction of flow. How to determine the direction of flow? My approach- I can use a pitot tube but for that I have to drill a hole in the pipe ...
• 395
63 views

### Does a venturi cause strain on a pump

Excuse my terminology if it's wrong. I'd like to know if a venturi causes strain on a pump. For example, in my drawing. I have an air pump behind the house with a 50mm pipe fitting. On the other side ...
• 103
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### Pressure variation through reduction (Bernoulli) and pipe wall design

Let's say I have a pipe followed by a reduction and then another smaller diameter pipe continues. Using conservation of mass, the flow through the smaller diameter pipe will have higher velocity. If I ...
1 vote
2k views

### Head loss coefficient for a valve with respect to both the open position and flow rate

This question talks about the head loss coefficient for a valve, i.e., $K_{L}$ for $h_{L} = K_{L} V^{2} / 2g$ where $h_{L}$ is head loss. First, head loss coefficient for a valve with respect to the ...
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### How to determine the "complete turbulence" boundary line in a Moody diagram?

Most Moody friction factor diagrams (like this one) show a dashed line frequently labelled as either "Complete turbulence", "Wholly turbulent flow" or "Turbulent flow", ...
63 views

### Water dynamics in aluminum pipeline for dummies

This topic is totally alien to me, so I may be asking something very obvious. I am designing a cooling system. In the bulk of aluminum, I drill 3mm holes and then I connect them one to another to ...
1 vote
1k views

### Pipe network analysis: static pressure of a closed-loop pipe

I've learned fluid dynamics but does not have much knowledge about its real-world applications. My question is about the static pressure of a closed-loop pipe. [Fig. 1. Pipe network. Source: ...
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103 views

### Question on fluid flow measurement uncertainty

Say you are trying to measure the liquid flow rate (mass or volume) through a pipe and you want to get the best measurement possible, and you have two flow meters. In one scenario, you put one flow ...