Questions tagged [valves]
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74
questions
0
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2answers
43 views
How to simulate open and close and control valve using a simple controller
I have successfully developed a mathematical model for my physical system. My objective is to control the mass of gas in and out of the system.
The mass flowrate is given by:
$V_f = C_d.\sqrt{2.\frac{\...
1
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1answer
55 views
What kind of solenoid valve should I use for vacuum?
I'm currently working on a project in which I have to control 2 solenoid valves with arduino to switch the suction of a vacuum pump from one tube to another one (tried to explain it on the photo), I'...
0
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1answer
58 views
Valves and plumbing size
I'm building a liquid rocket engine and we're using kerosene and oxygen as our propellent. Now my question is what pipe size should we use? My flow rate for kerosene is 0.160 Liters per second and we ...
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0answers
43 views
Selecting a water pump for low flow and 1 Bar pressure
I am designing a small automatic drip irrigation system. There will be about 10-15 drippers. Flow through the system will be about 1 l/minute, but this may change if expanding or reducing the system. ...
0
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0answers
24 views
Approximating volume flow based on valve opening
I want to approximate the volume flow going through heating/cooling units, but all I have are valve openings (unit=%). Since the valve does not have a linear relationship between its opening and its ...
0
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0answers
24 views
Pneumatically operated three way valves
I basically need to replace these valves with a modern equivalent
It’s a pneumatically actuated three way valve for high pressure and flow rate (200 bar, 50 liters/minute). The liquid is basically ...
1
vote
1answer
30 views
Can air flow occur in both directions in a 2 way solenoid valve?
I'm designing a system where I need to fill and exhaust air from an an air bag. The air will be supplied from a dc motor. As of right now I've been considering placing a 2 way solenoid valve for air ...
4
votes
0answers
67 views
Part to pierce the valve on a 16g CO2 cartridge and connect to a Solenoid valve
The specific part that I’m after is something that can connect to a solenoid valve and a CO2 cartridge that will break the seal on the end of the CO2 cartridge.
The solenoid valve connection is ...
0
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0answers
42 views
Is there a valve design or system that can do this?
I am trying to come up with a way to bleed air from a tube to avoid air (gas) from reaching the other end of the tube. Is there a way to do this automatically? It must be able to work in all ...
0
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1answer
43 views
0 energy one way valves [closed]
Is there such thing as a check valve that takes no energy from water for water to pass through? What is the name of this/these check valve type/s? I barely know anything about engineering, just have ...
2
votes
2answers
15 views
Does it make sense to have a pressure and flow controller on a single closed line?
I have seen P&IDs in which a single line has both a pressure and flow control valve. Based on my understanding of Bernoulli's equation however this doesn't make sense to me - because ultimately ...
-1
votes
3answers
62 views
How can I keep my soda bottle at atmospheric pressure while dispensing the liquid via a sealed system pump?
I am making a "bar bot" and I am trying to figure out a way to dispense soda without it going flat. I am using a bunch of peristaltic pumps:
Which luckily remain sealed at rest. I was ...
4
votes
2answers
67 views
Divide Flow and Maintain Pressure
Im in the process of building an espresso machine from readily available parts. I have a solenoid pump that supplies pressurized hot water to the coffee grounds. I want to be able to tune the pressure ...
1
vote
0answers
35 views
maintenance of steady flow through pressure or mass flow
let's say I have two points in a line, A and B. Between them there is a valve that can regulate the amount of the stream from A to B. Considering that there is a steady flow of the stream between A ...
1
vote
3answers
112 views
Is there a type of check valve that allows gas to flow in both direction but stops liquid from flowing back?
I have a pressure regulator to maintain a specified pressure in a vessel that also contains a liquid. The regulator can pressurize or relieve pressure of the vessel. I want to prevent the liquid from ...
2
votes
1answer
42 views
How to periodically shut down a recirculating hot water solar thermal system
I am posed with a scenario where a hot water solar thermal system has been setup. The system comprises of a cold water tank, heating arrays and then a hot water tank. The system is closed loop and ...
0
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0answers
143 views
Using one electrical pump for multiple hoses
I'm currently trying to figure out a cheap way to build a cocktail machine.
For now the machine should have about 20-30 possible input liquids. These liquids should remain in their original bottle ...
1
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1answer
2k views
How to inflate or deflate a bouncy ball that lacks a standard valve?
I found this bouncy ball in my garage. It is too deflated to use and too inflated to store, so I would like to inflate it or deflate it. It doesn't have a standard valve for a bike pump: the only ...
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0answers
42 views
Equation to calculate flow rate
Assume you have a solid walled sphere with an opening of diameter x. The sphere has volume 0.02 litres and has air at 1.4 bars.
What general equation would be appropriate to correctly size the ...
2
votes
1answer
70 views
Help with simple hydraulic circuit to use for a four legged Robot
Firstly i am new to hydraulics, i want to build a hydraulic circuit that powers 4 cylinders at each leg of a Quad-Wheeled-Robot. The idea is to move the Chassis of the Robot up and down in all ...
1
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2answers
277 views
PC Controllable DC Power supply (0-30V)
I have a Proportional solenoid valve that uses a 0-30VDC for control (opening the orifice) I only have capability to provide 0-5V or 0-10V. I need to control the valve using my PC. Is there any DC ...
1
vote
1answer
79 views
How are the modern hydraulic cylinders very precisely controlled?
My guess is that they use brushless Motors that in turn powers the hydraulic pump.
But there must be some kind of valve that could help in the process. Still the burning question is just by adjusting ...
1
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0answers
19 views
Valve advice for chiller test rig
I am in the process of designing a chiller test rig, of which a very simplified diagram would be (the quick coupling might just be replaced by a non-return valve):
I am struggling to find the type of ...
1
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1answer
22 views
Create low velocity pressure drop?
I need to create a variable 3-7 psi / 0.2-0.5 bar in a low density gas running through some piping. I can calculate the required Cv factor to do this with a valve would be in the 30-200 range. Looking ...
0
votes
1answer
107 views
Liquid Rocket Plumbing and Instrumentation Diagram: Standards and Presentation
I'm working on a team to build a liquid sounding rocket as a school project. We need to present our plumbing and instrumentation diagram, but we are butting heads on what program and standards we ...
1
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1answer
41 views
Build Device for Emitting Weak Air Bursts at Specified Frequency
I'm a neuroscientist interested in building a device to replicate the following study.
https://www.nature.com/articles/s41598-018-24924-9
Essentially, they sent air through a nose catheter to ...
1
vote
0answers
18 views
Is this Proportional Electro-pneumatic valve a direct replacement for other valves listed?
In the midst of trying to redesign the pneumatic subsystem of a combined system, I'm at the point of validating a new valve would serve as a direct replacement. The reason for the redesign is an ...
1
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1answer
44 views
Is there a male and female valve that is closed until connected together?
I'm trying to make a quick release male and female connector similar to the one shown here.
One connector is attached to the bottom of a container filled with liquid. When it is not connected it is ...
1
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1answer
692 views
What is the point of this valve that only allows air in and not liquid?
I'm looking at googles mocktails maker. And it puts 2 holes in a container. 1 hole is connected to a pump that will take water out and the other connects to a backflow prevention valve that only ...
2
votes
0answers
48 views
Liquid phase gas flow through valve
I have been trying to figure out how to calculate the required dimensions for liquid phase gas through a solenoid valve. Many companies (Swagelok, Bürkert, Asco) provide "Flow coefficient calculators" ...
1
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1answer
186 views
Reduce 180 degree rotation to 90 degree rotation without gears
I am actuating a small ceramic rotary valve with a cheap mg996 servo motor. The valve has a 90 degree max rotation from fully closed to fully open. Currently I have the servo shaft directly coupled to ...
1
vote
1answer
227 views
Check valve with precise cracking pressure
I have two containers of air, one at 100 kPa and rising, the other at 30 kPa and decreasing. I need a valve that lets air through when the pressure difference is >70 kPa. Where would I find a valve ...
0
votes
1answer
194 views
Typical tolerances for valve lift using a camshaft?
I am working on a linear actuator for a valve.
Wondering if anyone out there can point me towards the tolerances that are used for valve lift in a typical internal combustion engine using a camshaft?...
1
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1answer
77 views
Why does the water pressure initially drop then stabilize when pressure testing a valve?
Sometimes the dropping goes on so long(10-15 minutes) that the test is thrown out and the valve is opened and filled with water for a longer period of time. Pressure testers claim that it is because ...
2
votes
2answers
149 views
Deflection of a stack of disks under applied force/pressure
I'm trying to calculate the deflection of a stack of metallic disks, when subjected to a force.
In the case of the figure below, representing a valve for a shock absorber, the force is due to a ...
0
votes
3answers
119 views
How to find the balance position of valve downstream a tank?
We have a tank which has a constant inflow of water (Qi). The level (h) of water in tank is controlled by opening/ closing (l) a valve downstream of the tank. Overflow height of the tank is 4 meter. I ...
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2answers
52 views
Can I make check valve in simple workshop?
I need a check valve ( one way valve ) for my project which has less actuation force (IDK real term. shouldn't require high pressure for inflow of fluid) and I searched in market for the valve but ...
0
votes
1answer
77 views
How to maintain a static negative pressure in a valve?
My target is to create a valve with multiple inlet capillaries. And my output is a pipe of a larger diameter. I do not want to use any electrical systems, and at the same time, I want to maintain ...
0
votes
1answer
30 views
where to find / what to call a 3/4 inch air valve that can be opened/closed electrically? [closed]
I'm looking for something like this air valve:
(as discussed in https://engineering.stackexchange.com/a/12404/12007)
But I need to tube to be wider (3/4 in), the tube to be shorter (the shorter the ...
0
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1answer
102 views
Automated valve for testing module
I work frequently with materials sensitive to oxygen and moisture, within a glove box. However, there are frequently times I want to move these samples from the glove box to a scanning electron ...
2
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0answers
444 views
Best types of valves for dirty services
I've just started to learn Gate, Globe, Ball, and Butterfly valves.
I'm thinking about "dirty services" now.
Which types of valves are most suitable for dirty services, and what characteristics ...
0
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2answers
285 views
Valve first,then heat exchanger OR heat exchanger first then valve
In my exam, I was given 2 options to design a process. Assuming a saturated liquid coming out from the separator, A) should the stream pass through a valve to reduce pressure, then to heat exchanger ...
1
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1answer
5k views
Can PWM be used to control the flow of a solenoid valve?
Most cheap pump can achieve, according to the Amazon page, around 5 PSI and I would need something a way higher that can still be controlled.
I have this solenoid valve.
Can I use pulse-width ...
2
votes
4answers
449 views
Why to avoid low and high fluid velocities in hydraulic systems
I know that different geometries of piping, orifices etc... have different critical Reynolds values. If the value is exceeded laminar stream will turn to a turbulent form which causes a variety of ...
2
votes
1answer
51 views
What valve to use to divert incoming air from a pipe to another pipe stream?
There's an 4 inch exhaust stream that's emitting air at 2000CFM, I want to divide the exhaust in a 'Y' kind of outlet with two pipes.
If State 0- Exhaust out through one pipe.
If state 1- Exhaust ...
3
votes
1answer
461 views
What is this plumbing apparatus?
This device is about five feet tall. It is located in a ground-floor alcove in the exterior of a commercial building on a public street in Santa Monica, California.
Each of the chained manual valve ...
0
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2answers
2k views
Liquid vs. gas check valves
Suppose that I want to transport gases in a tube in only one direction. Can a liquid check valve be used in place of a gas check valve or is there a specific reason to use only a gas check valve?
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2answers
47 views
Toy ball check valve functionality and details
In the making of an inflatable toy ball (think of a basketball), a check valve is used to assist the user in the inflation of the ball by preventing backflow of inserted air. Is this check valve made ...
0
votes
1answer
55 views
Chicken feeder design and valve [closed]
(I'm not really sure what SE to post this on, so if this is inappropriate, my apologies)
I'd like to be able to remotely control the amount of chicken feed in the feeder. Here's how I envision the ...
0
votes
1answer
57 views
Best way to maintain flow of fluid under head?
I have a crucible with molten metal flowing under its own head. As per torricelli's law the velocity of the fluid would be $\sqrt{2gh}$.
Is there any mechanism with which I can maintain a constant ...
