34 votes
Accepted

What is the purpose of these diversions in a natural gas line?

The loops are known as expansion loops. They need to be placed in pipelines to enable the pipelines to contend with thermal expansion and contraction and other forces that can affect the pipeline. ...
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  • 9,447
19 votes

How thick is it reasonable for the walls of a steel gas pipeline to be?

It seems realistic to me. This is an undersea pipeline at depths of over 2 km. The pressure would be considerable at those depths (on the order of 20 MPa or 200 atmospheres). The pipe would need to be ...
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  • 2,631
15 votes
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Why do water mains break in the winter?

Cold makes things shrink. Despite being buried — presumably below the frost line — both the ground outside the pipe and the water inside the pipe are much colder in winter than in summer. ...
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  • 6,749
14 votes

How is gas flow through (extremely long) pipelines monitored and controlled?

It's important to remember that these pipelines don't exist as a single isolated line and will have a number of branches that tie into the main pipeline and split off for gas to be sold to different ...
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13 votes

How thick is it reasonable for the walls of a steel gas pipeline to be?

Is such wall thickness realistic for an industrial gas pipeline? Looking through ASME B36.10M-2004, Welded and Seamless Wrought Pipe, there are plenty of pipes that have thicknesses in that range. ...
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  • 3,587
13 votes
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What is the maximum length of oil pipelines?

The total length of the pipeline has little to do with the length that oil can be pumped in a pipe. This is because a pipeline is broken into many smaller segments between pumping stations. Stations ...
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9 votes

What is the correct pipe size for a 2inch pipe?

As of the 2013 edition of ASME B16.5, the scope section explains: This Standard states values in both SI (Metric) and U.S. Customary units. As an exception, diameter of bolts and flange bolt ...
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  • 4,501
8 votes
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How are blanking spades entered into gas pipelines?

The most straightforward way would be to mount them between flanges, after a section of pipe has been valved off and flushed. This is correct. Blanking spades, also known as slip plates, slip blinds ...
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8 votes
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How to know whether the flow is supersonic in a nozzle?

From my brief involvement in shocks, I think the most likely solution would be to image the exhaust, probably optically, but maybe using interferometry or something depending on what the exhaust is. ...
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  • 1,025
6 votes

How can I calculate the stresses and limits for the physical lowering of in-service pipelines?

This is something that I've looked at with tunnels, rather than pipes, and arguably with smaller deflections. Hopefully it'll be some help, however. If you can satisfy yourself that the rate of ...
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6 votes

Water pump at top floor or bottom?

Think about the pressures. With the pump above the supply line, the pressure at the input of the pump will be lower than the supply. At roughly 2 PSI per foot, you're down about 18 PSI. Since air ...
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6 votes
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What is the correct pipe size for a 2inch pipe?

I would guess that the discrepancy is down to rounding fractional inch sizes to decimal inches ie 2.38 is not exactly 2 3/8" Note that 2.375 (two and three quarter eighth inches) is 60.325mm
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6 votes
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Why is the friction factor in laminar flow independent of pipe roughness?

In laminar flow, you assume a fuild layer near the pipe wall with flow velocity = 0, and progressivly faster flowing layers towards the middle of the pipe. That's why it's called laminar. Because ...
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  • 4,618
5 votes
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One way plastic rubber pipe

Your idea would not be too hard to construct. The one direction tines can be installed through the side of the pipe. Any springy rod material could be used; plastic rod, spring steel, etc. Rubber ...
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  • 7,469
5 votes

Force required to empty a syringe

You can get a minimum bound from energy balance alone. This is as if the fluid has no viscosity, so the force you have to apply over the distance is only due to the kinetic energy required to expell ...
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5 votes
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What material is used to make gas pipes?

In my admittedly limited experience working with plumbers, natural gas pipes are typically made from galvanized steel for interior work, or from black steel pipe for underground. Last-leg fittings and ...
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  • 3,971
5 votes
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Is steel air (argon) tight?

Steel is routinely used for high pressure storage of industrial argon. For practical purposes it is certainly 'gas tight' although there may be a certain amount of atomic level diffusion into the ...
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5 votes
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How Can I Determine Multiple Discharges from a Pipe Network? (Knowing the Inlet Conditions)

The flow of current in a circuit is broadly analogous to fluid down a pipe, with the resistance of wires/resistors combining according to standard laws. If you can break your pipe network down into ...
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5 votes

How Can I Determine Multiple Discharges from a Pipe Network? (Knowing the Inlet Conditions)

You have 9 unknown values you are seeking (the flow at each of 9 outlets), and one that you need to find in the process (the total pressure drop) From the given information, you can assemble ...
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  • 81
5 votes

Direction of fluid flow

Heat the pipe at some point, and find the direction in which heat transfers. This will give you the direction of the flow. Caution: Don't do this for flammable fluids. Thanks to @Carl Witthoft for ...
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4 votes

How is gas flow through (extremely long) pipelines monitored and controlled?

For question 1, as far as I recall, fiscal metering of long hydrocarbon gas pipelines is done with coriolis effect mass flow meters. To calculate Mach number, all that would be required is the mass ...
4 votes

Why do water mains break in the winter?

Water main failures are greater in the winter months than in the spring or summer. As a water utility professional in northern Illinois we have around 120 failures each year with 20 + years of data. ...
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4 votes

What is the pressure to secure certain temperature?

Pressure adds only a to the temperature of water. Pump pressure allows water to be moved, it is not used to maintain the temperature of the fluid being pumped. To minimize thermal loss of fluid in a ...
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  • 228
4 votes
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How to make sure a pipe does not take all of the water from a stream?

You can put a valve on your pipe to control the flow. Or partition the stream by means of a short concrete wall which looks like an indented grout trowel upside-down . Say two opening for the stream ...
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  • 21k
4 votes
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Divide Flow and Maintain Pressure

Short answer: I suspect that so long as your pump is a positive displacement pump (ex: the "vibratory pump" or "rotary vane pump" as described in this webpage about espresso pumps) and is sized to ...
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4 votes

Direction of fluid flow

Yes, purchase an ultrasonic flow meter. Needs a straight length of pipe and very careful placing of the sensors. However, if done well one can get good results, if not then the results can be ...
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  • 13.9k
3 votes

How to know whether the flow is supersonic in a nozzle?

That is a really nice thought experiment! In general I would argue that you only need to know: Total-Pressure ( $p_t$ of your supply) Static/Ambient Pressure ( $p_\infty$into which you are expanding) ...
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  • 1,202
3 votes
Accepted

How does a union joint with two male threads work?

Typically, most threads on pipes (in the USA at least) are male NPT and all the couplings or fittings are female NPT. You can connect two pipes with a coupling as long as the last pipe added is free ...
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  • 7,469
3 votes

How thick is it reasonable for the walls of a steel gas pipeline to be?

Why would you need that much steel for a gas pipeline? Remember that the force on the inside of a pipe is proportional to pressure*diameter. So a large pipe needs to be much thicker than a small pipe ...
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3 votes

Distribute 6 inputs to 9 outputs with pipes

I recommend approaching problems like this by starting with a base case and working up from there until you see a pattern. For piping, the base case is a straight case with one input flowing to one ...
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  • 3,211

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