# Tag Info

34

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. They are typically placed in gas pipelines, irrespective of when the gas is hot or cold - natural gas or steam. The following quote is from Pipeline Design. It's ...

19

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 thick enough to withstand these (very high) pressures. The Nord Stream pipeline under the Baltic sea is at depths of up to 210m and uses 1220 mm diameter ...

15

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. This causes the pipe segments to shrink, putting tension on the joints, and increasing the chances that a weak one will fail. By contrast, warm weather puts the ...

14

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 locations. This touches on a very broad subject of flow assurance and pipeline network modeling. The pipeline will also be broken into smaller sections by ...

13

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. For example, 16" diameter, Schedule 160 pipe is 1.594" thick: This translates to about 40.5mm thickness. As another extreme example, 24" diameter, Schedule 160 ...

13

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 are conveniently located either where required (see discussion below) or where another pipeline joins in. Pipelines are rarely one single pipe between point A ...

9

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 holes are expressed in inch units only. These systems of units are to be regarded separately as standard. Within the text, the U.S. Customary units are ...

8

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 or spectacle blinds, are usually slipped in between two flanges after a process line has been double blocked and bled. They are usually secured in place by the ...

8

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. The most obvious indication that you have supersonic flow is if you can see a shock diamond. I think you could probably also work it out from the length of the ...

6

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 curvature is relatively small- then you can approximate the stress generated by the lowering using simple beam theory: $$\sigma=\frac{Ey}{R}$$ Where: E is the ...

6

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 pressure is about 15 PSI, the system will at least work as long as the supply pressure is over 3 PSI, but that's still not a good situation. If the "supply" is ...

6

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

6

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 there is no flow near the pipe wall, the roughness does not affect pressure loss. In most practical applications, you will be outside of this flow regime. Then the ...

5

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 would probably not be a good choice since it has higher friction and less restoring force than similarly sized plastic or spring steel. Drill holes in the side of ...

5

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 the fluid. The diameter of the tube is 1 cm, so the area is .785 cm². That means the plunger travel distance is 25.5 cm = 0.255 m. The fluid is squeezed ...

5

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 tubes which connect the stub-outs to various appliances are sometimes made from copper and brass. Other materials are possible, as noted here. Some things to ...

5

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 material in the long term but this is more about contamination than actual leakage. As mentioned in comments the quality of mechanical and welded joints is also ...

5

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 small segments of known "resistance", then you can use current laws, and widely available circuit simulators to get a good approximation of the outlet flow (or at ...

5

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 equations that you can solve using linear algebra methods. The sum of the flows at the outlets will equal the inlet flow: Q_t = Q_a + Q_b + Q_c + Q_d + Q_e + Q_f + ...

4

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 flow and the temperature from a thermocouple (along with some estimate of the mixture's heat capacity ratio.) This answer needs checking against reliable ...

4

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. Each and every year we have 90 of the 120 between December and March (Fact). The question that indeed is hard to define is why? Here are the facts I see year ...

4

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 pipe, the pipe need to be sufficiently insulated.

4

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 and one leading to a small pond downstream feeding your pipe.

4

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 output the flowrate you desire, then you only need a discharge valve or an appropriately designed flow restriction device (ex: a restriction orifice or your "...

3

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) Taking into account the uncertainties (or tolerances) you will know whether your flow will have reached $M=1$ in the throat (or how likely it is that it has ...

3

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 to rotate about its axis. A union is used for easy removal of pumps and other serviceable equipment that would otherwise not be easily unthreaded. It is also ...

3

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 for the same pressure.

3

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 output. Depending on the exact specs of the problem, this requires either 0 or 1 valves; it does not require any branching. I------O (or, I--▷◁--O) Add an ...

3

So, I attempted to solve a simplified problem using Bernoulli, it is an approximation though, since it doesn't account for the change in flow direction and subsequent turbulence caused after the hole. I rearranged equations for volumetric flow rate and head loss. Please let me know if you spot any errors. Note: the last two lines rearrange from an earlier ...

3

The way this would typically be achieved, is with an off-the-shelf "Tank Connector". This essentially replaces the welding operation in your first idea. Simply cut the appropriately sized hole, and install the connector. There are face seals on both sides of the sheet metal, which are clamped tight. I've shown a brass connector, since I thought it was the ...

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