Valves and Pipes

File: ballValveAnimation.gif (80KB, 350x253px) Image search: [Google]

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>>8428614
Some valves have a ball mechanism like this

(remember on a real pipe, it would not be transparent and the mechanism would be hidden by the pipe's siding)

>>8428614
>What kind of scientific developments have been made in the way of Valves and Pipes?

gonna let you in on a secret. fluid behavior still baffles the fuck out of scientists. the best we have are a bunch of numerical approximations based off a 70+ year old model.

doing CFD is honestly more of an art at this point.

File: butterflyValveAnimation.gif (50KB, 350x221px) Image search: [Google]

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>>8428620
And other valves have a flat plate like this for their mechanism, called a butterfly valve. I wonder why the different kinds exist and what they're each good for

How do they pressurize water? mind = blown

>>8428633
Well since water is incompressible, i think when they talk about pressurized water they are talking about changing the pressure of a small amount of another compressible fluid in the pipe, such as air. This air gets in front of a large volume of water and by changing the pressure of that air pocket, it "moves" all the fluid, well that's how i imagine it would work, it may actually impart pressure to the water, who knows

>arent pipes cool?

so glad i dropped chemical engineering first year of undergrad

>>8428640
What do you do now anon

How does water in reservoirs not go stale if water left in a glass of water exposed to air does? mind = blown

>>8428620
>>8428625
Well i am not an engineer but i would think the ball valve is better for higher pressure applications? because it looks like when its set to closed it has a sturdier section holding back the fluid

>>8428623

so

is there any way to plug our best models for fluid dynamics into a really fucking big computer & run it for a very fucking long time & come up with a general approximation of the principles

or is that what we already do & it isn't good enough because guessing is dance-on-your-mothers-grave offensive to mathematicians?

>>8428672
guess and check is how a surprising amount of problems in engineering were tackled, see: the Jet Engine for instance

It works very well when you have a lot of time to test, iterate and improve the accuracy your guesses

>>8428614
Generally speaking the color of the valve handle corresponds to the substance flowing through the pipeline. Each plant has their own color code which may differ by state or country regulations.

However, This is not mandatory in all countries or organizations so valve color may just be the manufacturers choice.

>>8428689
Speaking of valve labels, have there ever been accidents where a valve was turned the wrong way by mistake? Does labeling valves help with this?

>>8428614
>>What kind of scientific developments have been made in the way of Valves and Pipes?
We sort of understand pipe flow now.

Pipes and valves are really just engineering stuff though.

>>why are some valves painted Red? Is there any significance to that?
easier to see.

>>8428694
Each valve on a process pipeline has to be tagged with an individual ID# .
These days, most western countries have strict regs regarding pipe labeling. google marking services inc. Leading company in turnkey plant and rig labeling.

Yes there were serious accidents in the past.
Not so much now as valves on major process lines are remotely activated by computers/ engineers in the comfort of control rooms with a stack of P&IDS.

>>8428698
>>8428623
What's up with this "mysterious" nature of pipe fluid dynamics? Shouldn't it just be fluid in + geometry of pipe * pressure = fluid out?

>>8428708
Thanks for answering my questions this stuff is real interesting, it looks like quite a lot goes into these little mechanisms and making sure everything works right and is properly labeled.

>>8428614
your fetish is very specific i must say

>>8428623

The main issue is that fluid flow is governed by highly nonlinear PDEs, the computational expense of CFD scales roughly with the cube of the Reynolds number, turbulent flow is exceptionally difficult to resolve down to the relevant length scales, and turbulent flow is also sensitive to initial conditions. That's just a few of the problems.

>>8428625

One major factor in valve design is opening speed. Valves designed for liquids generally open slowly to prevent water hammer while other types of valves (like QEVs and pilot valves) are usually designed to open rapidly.

My fetish is magnetohydrodynamics

I'm hot for hot fusion

Cost is also a large factor. In a city water supply most valves are gate valves. But these valves should not be used to throttle the flow of water.

>>8428614
the fuck?
do you have a pipe fetish or something?

>>8428620
>>8428625

>1/4 turn valves

Enjoy your water hammer.

>>8431202
wa·ter ham·mer
noun
a knocking noise in a water pipe that occurs when a tap is turned off briskly.

So its just an unsettling sound? Literal autism at works ladies and gentlemen, the scary sound of water hammer will spell ruin for us all!

>>8431238

Water hammer is more than that. The flowing fluid stops suddenly when the valve is closed. That change in momentum causes an impact load that can burst pipes and cause other types of damage.

>>8428711
Depends on the type of flow (laminar,transient or turbulent), the fluid (viscosity, compressibility), the interior pipe surface (rough, smooth, material), the pressure, the cross-section/area of pipe, the dimensions of turns (long turns, abrupt, turbulence), and a lot of other shit i really can't remember off of the top of my head atm.

>>8431248
This is a real engineering concern. water main T-intersections and endlines will often have a "stop block" constructed to prevent lateral/inline movement.