# Tag Info

6

I think the best (and simplest) way to describe something like this is Bernoulli's equation. $$P+\rho gh+\frac12 \rho v^2=constant$$ To use this, we're looking only at instantaneous velocity, because as the air leaks, the pressure will go down. We also should assume that the "valve" is really more of a small hole than anything that fluctuates too much ...

5

I'm going to cheat by referencing the patent. ;) Automatic Bar Controls owns the Wunderbar site and has a patent on the product. The patent is US008925769. The actual detail drawings don't seem to be available there though, so you have to get it straight from the US Patent Office listing. The name of the patent is: Wireless spout and system for dispensing. ...

5

Yep, the answer is a bit more interesting. The mass flow rate ($\dot m$) will vary as $C_d A \sqrt{2 \Delta P}$ (discharge coefficient, cross sectional area, and change in pressure across the valve). Barring compression of the fluid, velocity will behave the same way. The devil of the thing is in $C_d$. This is pretty much something that you have, measure ...

4

A valve that is smaller than the pipe diameter will reduce the flow rate, but so will any valve. When calculating what sort of pressure/head loss (pressure and head are equivalent) a system will have, there are two contributing factors: major losses and minor losses. $$h_{total}=h_{major}+h_{minor}$$ h_{major}=\lambda \left( \frac{l}{d_h} \right) \left( \...

4

it has to be water for fire because its red. its on the out side so they can control the water without going into the building. the open pipe is to drain the water for maintenance. it does not have a meter on it so they are not paying for the flow of water.so for fire. all the valves are open. chains are so you cant open or close the valves. the electric ...

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

You're looking for a pressure regulator (and this is indeed what you need in your use case, but that is another question.) The regulator works so that over a range of flows, the pressure on the outlet side is kept constant.

3

Look at pinch valves: A small piece of tubing that can be pinched shut pneumatically or mechanically (solenoid). When open, you have the full diameter of your tubing. The only part that touches the medium is the tube, and you don't have any sliding seals. The latter part is important, because you don't want to mess up your beer with sealant grease and you ...

3

What you are describing is a gate valve and you are correct in assuming that this would not cause foam. Unfortunately, I do not think that gate valves are manufactured in the small size that you need. If your tubing is 3/8" ID, that is approximately equal to schedule 40 1/4" nominal pipe size. I have never seen a gate valve smaller than 3/4" nominal pipe ...

3

My first guess for any medical pump is a peristaltic pump, as they can pump one fluid then another without contamination (by swapping lines). Couple this with the fact that they can also be multi-channel pumps, and I'd almost guarantee that this is what it is. I've seen maybe one instance of non-peristaltic multiple pumps on one shaft (not counting turbo ...

3

This device works on momentum effects. If the fluid had no momentum, it could just follow the channels wherever they go, and the resistance would be the same in both directions. In the context of the fluid, the is what happens when the viscocity is high and the speed low relative to the size of the channels. In short, this only works over a range of ...

3

The manufacturer says this about maintanence: annual testing of the non-return valve, body leak tightness and flow capacity is recommended WITT is happy to supply special test equipment Flashback Arrestors are only to be serviced by the manufacturer; the dirt filter may be replaced by competent staff Given that you inherit this equipment ...

3

It is possible to modulate the drive of some types of solenoid fluid valves to ultimately regulate the pressure of the fluid at their output port. I have designed a product that does excatly that. However, you can't easily use any valve. You want a valve that is intended for part-way operation between full on and full off. There are such solenoid valves, ...

3

I think the key information is that the liquid is saturated. This means any reduction in pressure will lead to partial vaporization and two phase flow. For heat tranfer best overall heat transfer coefficient is always direct to liquid rather than vapor. You still will have vaporization once the saturated liquid once it enters the heater, but the effect ...

3

Check Valves are available with adjustable cracking pressures, using a preload spring to control the poppet force, for example: http://www.my-ssp-usa.com/products/valves/check-valves/adjustable-cpa It's important to note, however, that there is a degree of histeresis with these valves, and once open, they will not close if the pressure difference drops a ...

3

Yes, normally you can pull those plugs out - takes a strong grip or « folding » the ball to be able to push on the inner end of the plug... Here is a photo with such a plug taken out:

2

While designing a relief the valve flow rate is the deciding variable. To calculate its value in two phase flow different models can be used like HEM, drift flux, separated flow, etc. For this particular application (where two phase flow is because pressure drop across valve) HEM is best suited. I would also suggest to check for choking in the two-phase ...

2

That would be Process Industry Practices, Practice Ref. PIC001. Issued 7/15/1998. Appendix A1 contains exactly what you listed. Edit: I just came across this online: PIC001 Sample, Not for Commercial Use

2

You need verify that your replacement has: 1/16" orifice(commonly available) Now, what are the size of the theads on the inlet and outlet(1/8" npt?) it might be stamped somewhere on the valve body. Also, unscrew the 90deg adapter and check. 24/60 would indicate 24volts AC at 60Hz.(not very common) If you can check the two lines connecting the solenoid with ...

2

As far as engineering systems go, it doesn't get much simpler that a pressure regulator; single or double. The mechanical feedback is solid solution. Wiki link for pressure regulator operation (for future readers reference) There are other ways to regulate pressure with various tradeoffs. For a fixed flowrate you could size an orifice to reduce the ...

2

I think you can create a self-starting siphon if you are able to add pipe to both ends of the "drain pipe." You'd extend the output end downwards until the exit of the pipe is below the bottom level of the ditch. The inlet end of the drain pipe is extended down to the bottom of the ditch (with possible filters, etc). If I got this right, the ditch will fill ...

2

Your option 1, done "according to specs": Two check valves and a pressure regulator with separate output and regulation input (these are usually joint; output pressure being the regulating/feedback pressure; you need a variant with these separate). The regulator has regulation input open to air, throughput input in your circuit, output to the tank, through ...

2

No, liquid check valves function on density, viscosity or velocity or a combination and the mass is taken into account - gas check valves are designed to deal with a fluid 700 or more times less dense than a liquid. Some gas check valves will function with a liquid - a check valve designed for blowing up party baloons for example will work with a liquid at ...

2

Between disc 1 & 2, there is a reaction force on disc 1 which is not going to act on the edge rather at the distance of 2nd disc edges. This means you need to have the model of 1st disc bending developed for 2 cases, Pressure drop load acting at the radius of 2nd disc For the 2nd disc, you have 2 cases reaction load from the 1st disc at the edge of ...

2

There are many, many different commercially-available designs of fluid connectors that shut off automatically when disconnected and open up when connected. They are available in plastic and metal, permanent and disposable, in all sorts of sizes. Try a search on "make-and-break fluid connectors".

2

I would not mess around like this at all. I would make a secondary heat dump (old radiator in the garden, swimming pool...) and divert excess heat there.

2

If the flow rate is low for the gas then a ball that floats on the liquid will work - similar to how most wet vacs stop liquid getting into the motor...

2

In addition to NMech's answer, the pressure regulator sets the maximum pressure that the system will see while the flow control limits the maximum flow that the downstream system will receive. This may be important in filling or pressurising the system and may also limit the flow rate in the event of a burst or severe leak.

2

A typical 2 way solenoid valve would not restrict airflow towards one direction. So in your case is perfectly valid, since you will be removing the pressure from the inlet. What you would normally do if you wanted to prevent backflow is to place a check valve. Below is a cutout of typical two way valve operation states.

1

Depends on the design - some just use a soft plastic tube that collapses in on itself to seal. That is why some inflating kits have long needle adaptors amongst others in them tapered or parallel. The maximum pressure a check valve could withstand IMHO is probably far greater than the material used for that ball itself. So, if you over pressurise it then it ...

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