Questions tagged [valves]
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59
questions
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1answer
38 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 ...
0
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0answers
31 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
50 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 ...
0
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1answer
67 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
67 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 ...
0
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0answers
40 views
Avoid loosen of a cartridge valve caused by embedding
This problem is (mainly) caused by the small clamping length. And this clamping length is predefined through the standardized cavities – exemplary I mention ISO 7789.
Of course you can raise your ...
1
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0answers
16 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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0answers
11 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
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1answer
33 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
vote
1answer
36 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 ...
0
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0answers
17 views
Technical name for vacuum float liquid shutoff valve?
I am working on a "maker" hobby project involving a vacuum/blower motor. I want to make sure that if the suction pipe is accidentally (or intentionally) placed in water that the liquid will not be ...
1
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0answers
15 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
vote
1answer
41 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
vote
1answer
117 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
30 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
vote
1answer
66 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
95 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
77 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
vote
1answer
29 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
1answer
63 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
2answers
68 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 ...
1
vote
2answers
34 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
49 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
27 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
votes
1answer
89 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
146 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
votes
2answers
91 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 ...
0
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1answer
2k 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
137 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
44 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
296 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
votes
2answers
1k 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?
0
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2answers
40 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
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1answer
44 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
51 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 ...
1
vote
2answers
277 views
How much is too much control valve cycling?
In a textbook on process controls, I read that when tuning a controller there must be a balance between performance and excessive control element cycling. My question is, what corresponds excessive ...
1
vote
2answers
387 views
Water valve for over 120C temperature
I am making a project where i need to put a water valve below the tank and then need to open it automatically but the problem is that already available brass electric valves aren't good enough to ...
0
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1answer
42 views
Can I increase pressure on the output side of a backstop/security valve?
I'm working on a system with non-deterministic pressure (because it's based on bio mass fermentation) where CO2 is generated and input into the system at maximal pressure ...
3
votes
1answer
27 views
Is there a (sort of inverse security) valve which opens if one connected side has a pressure below a certain value?
Security valves with two connectors open if the pressure exceed a value x +/- tolerance on one side. I'd like to know if there's a mechanical valve which opens if the pressure on one side sinks below ...
3
votes
4answers
184 views
Which components to use for a CO2 gas storage?
I have a CO2 production for my aquariums (currently 2, but the solution should be extenable to - let's say - 5) based on fermentation of bio mass (CO2 is used as fertilizer there) which consist of a ...
3
votes
1answer
293 views
Automatic siphon above max height
The soil in my area has a very thick clay content (apparently left behind by glaciers, damn ice age). Because of this drainage in my yard is horrible. I've put in some underground drainage (french ...
1
vote
1answer
59 views
How can I build a electronically controlled valve for a 1/4 inch tube
I'm looking for a practical efficient way to open and close a 1/4 inch gravity fed hose. Initially I was thinking of using a Solenoid, but can't find anything suitable. My second thought was using a ...
2
votes
1answer
1k views
How strict is the direction of air flow in a single direction pneumatic solenoid valve?
I am currently designing a small pneumatic system that pumps air into an airbag, holds the air in, then releases it to the atmosphere. Each pump in the system actually feeds two sets of airbags and ...
0
votes
1answer
58 views
Is there and easy way to go from 1000 psi to 45 psi without a complicated pressure regulator
I have a C02 tank that is filled at 1000 psi. it's got a duel pressure regulator that allow you to dial it down to 45 PSI. Is there a simple way to regulate pressure from 1000 psi to 45 ( non ...
2
votes
0answers
70 views
What specific characteristic of proportional solenoid valves makes the flow to current behavior quadratic?
If experimental data is obtained from a proportional solenoid valve, specifically flow vs current (assuming inlet pressure is constant), the fit is nearly quadratic in nature.
Andersen's Analysis and ...
1
vote
2answers
399 views
Reverse float shutoff valve
I have an application that is drawing fluid from a reservoir via a standard dip tube. This application has a special requirement that once the fluid is depleted from the reservoir, the pump pulling ...
2
votes
1answer
201 views
Fluid dynamics: valve and pressure drop
I have a question regarding valves: Let's assume a district heating system where you want to control the mass flow in a sub-station with a valve.
Is (in normal cases) the diameter of the valve (fully ...
0
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1answer
114 views
Decoding pump- valve analogy for medical instrument
I am referring below diagram where pump and valves are used to allow waste, diluent water control in biomedical instrument.
But I am not able to get how single pump can have multiple port, I have ...
6
votes
1answer
145 views
Is it possible to replicate a Tesla valve in large scale?
Supposedly a Tesla valve will impede fluid or air flow in one direction whilst allowing flow to move freely through the valve entering from the opposite direction, without using any moving parts. Also ...
3
votes
1answer
120 views
How to evaluate solenoid valve specifications
I need to replace a solenoid valve, and I need help in identifying the specifications that I should check for an equivalent replacement.
This is a picture of the valve itself:
Click for larger image
...
