Questions tagged [valves]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
0 answers
21 views

Can the debris found in seawater compromise the sealing of a subsea check valve?

In the event of a subsea check valve opening and debris lodging in the region where sealing takes place, could that make the valve not close when it should? Would that happen to debris of any size? If ...
Lucas Cruz's user avatar
0 votes
0 answers
17 views

Why isn't my valve controller not providing sufficient amount of voltage to my fan?

We're using the valve controller below to control the speed of a (generic) fan: https://products.axiomatic.com/viewitems/valve-controls/can-to-4-outputs-valve-controller Problem: We're supplying the ...
tadm123's user avatar
  • 103
0 votes
1 answer
22 views

Operating a latching 24V DC valve with non-reversible current direction signal

Most 24V DC latching valves require a reversal of the current flow direction to be able to switch between open/close states. However, is there a way to operate them with a signal that can only go 0V ...
Noideas's user avatar
  • 13
0 votes
0 answers
60 views

Normally open check valve

What I'm looking for is basically an always open check valve that closes at a certain pressure. ~5psi. The application is a breather vent that closes if the valve is submerged in water. Would a biased ...
user43508's user avatar
0 votes
3 answers
67 views

What does 12CC refer to when talking about voltage?

Is it 12V with a connector? For example in the data sheet here: https://www.hydraulicmegastore.com/product/vcf12nc12cc/ Is this related in any way? (A DMP-12CC connector cable) https://www.monacor.com/...
cookingoil2000's user avatar
1 vote
2 answers
65 views

What would prevent me from using this valve for water?

https://www.kingstonvalves.com/product/ksv25cr-stainless-steel-asme-soft-seat-safety-valve/ Looking to use this for water instead of air. I haven't seen a good reason not to as the physics of the ...
Jirhska's user avatar
  • 111
0 votes
0 answers
49 views

Why no lever tools were used during manual valve opening attempts in Fukushima Daiichi?

I watched a PBS documentary https://youtu.be/qRKScRgsUaE and Netflix series about this accident. Both show very slow and strenuous attempts to open a valve manually. Why there was no use of level ...
Paul Jurczak's user avatar
1 vote
3 answers
51 views

Volume multiplying hydraulic pressure reduction unit?

I'm tying to figure out what something is called, assuming it exists at all. If I knew what to search for, I'm reasonably sure I could figure out which part would be suitable for the application, but ...
BCS's user avatar
  • 179
0 votes
1 answer
25 views

How to prevent liquid backflow when pumping an upside-down liquid container with air to pressurize it?

I'm trying to design a system that will have glass bottles upside down filled with liquid. They will be pressurized via a bulkhead air input and will dispense through bulkhead liquid output. Here is a ...
Taako's user avatar
  • 107
0 votes
1 answer
163 views

Displacement and force control with pneumatic cylinder

Good day, I was confronted with the task to develop a new controller for pneumatic cylinders. The control channels are displacement and force. A load cell is used to measure the force (analog signal). ...
Paul's user avatar
  • 1
-1 votes
1 answer
171 views

How does the hydraulic valve system work in excavators?

There are many types of valves used in excavators. Two are important: the main valve and the pilot valve. Is the pilot valve is controlled by the operator and the main valve is controlled by the pilot ...
Prerna 's user avatar
0 votes
0 answers
38 views

Do 6/3 proportional valves like this exist?

Like a directional valve but used to select either pair of supply and return. Could be done with two regular 5/3 valves, but it would be nice to use only a single valve. Does something like it exist?
K0ICHI's user avatar
  • 101
2 votes
1 answer
44 views

Improving O-Ring/flapper valve injection mold ->non-engineer

I make specialized flapper valves that are similar to O-Rings. The current model uses aluminum sheets as base disks that adhere to the rubber (2 part urethane). The rubber is poured into the waxed ...
Lilly Whelan's user avatar
0 votes
3 answers
70 views

Passive gas mixing valve that takes fixed ratio of gas from two different inputs

I am designing a device that requires a gas (air) valve that takes the same volume of gas from two different input ports IP1 and IP2. The output port OP will have lower pressure than both of the ...
Karl H's user avatar
  • 3
0 votes
1 answer
108 views

Confusing terminology for "normally closed/open" - It means the opposite in electronics (relays) versus fluids (valves)

I'm an electrician and "normally open" / "normally closed" is well known to me. I recently started to also work on heating systems including the pneumatic system that controls some ...
Mads Skjern's user avatar
0 votes
2 answers
214 views

ELI5: How does this water (solenoid) valve work?

I took apart this hose faucet timer: When unpowered the valve is closed. When powered (either manually or by timer) it opens allowing water to flow through. I am attempting to learn how the open/...
n00b's user avatar
  • 103
0 votes
1 answer
71 views

What are the issues with this ICE design?

Elaborating along this previous question, could you please invalidate this ICE design with solid authoritative arguments explaining all the flaws? Starting hypothesis: Whatever the purpose, one single ...
user avatar
0 votes
1 answer
41 views

User-settable pressure-relief valves for outdoor domestic water supply lines?

Is there such a thing as a pressure relief valve which can be attached to garden hose bibb threads that would relieve backpressure from a pressure washer, in order to protect old pipes and reduce the ...
Tim's user avatar
  • 225
1 vote
2 answers
66 views

Is there anything close to automatic shuttle valve?

I am building a pneumatic system that needs an automatic shuttle valve. That means if I apply air pressure on one of the inputs In1, it closes the other input In2 and creates a path between In1 and ...
NHB's user avatar
  • 11
1 vote
1 answer
64 views

Are there hydraulically actuated pneumatic valves?

I am working on a hydraulic system that is powered by an air-hydraulic piston pump, the pump uses pneumatic pressure to drive a piston which then pressurizes the hydraulic system. The system needs to ...
David's user avatar
  • 31
0 votes
0 answers
39 views

Diesel fuel valve outdoors: Gate, Globe, or Ball?

Real world question: We need to replace an internally failed (cannot shut) gate valve installed as a shut-off valve on a 2" Diesel fuel line exposed to weather (roof top) and operating at less ...
ehbowen's user avatar
  • 223
1 vote
2 answers
336 views

How does this transmission valve "hydraulic computer" work?

I just came across this: The claim is that it is a kind of analogue computer. But I don't see any moving parts. How does it work? EDIT: If someone could draw lines on the diagram to illustrate, that ...
spraff's user avatar
  • 131
0 votes
1 answer
63 views

Is there a pressure check valve that doesn't bleed the excess pressure?

My issue is that downstream, I have a boiler making pressure at 10.54 bar and upstream I have a system that must NOT be heated at any point beyond 130 °C. My plan is to make sure the system pressure ...
Pulkit Sharma's user avatar
0 votes
1 answer
35 views

Solenoid valve that does not restrict air flow when open [closed]

I wonder if such a valve exist - a cheap solenoid valve that when open does not restrict air flow? I've only found solenoid valves for compressed air, although the opening may very (4-12mm) there is a ...
Simon's user avatar
  • 115
0 votes
3 answers
93 views

Releasing compressed air with the loudest pop

Due to the dry summer I've been thinking about theory of making cracker/banger without fire. Would connecting a nozzle (de Laval?) to quick release valve from small cylinder with the pressurised air ...
Filip Matyja's user avatar
0 votes
1 answer
50 views

Plug valve problem

A pig is a solid plug that is introduced into the pipeline to be serviced. Fluid is pumped upstream of the pig to provide the necessary force to set the device in motion, and to perform the desired ...
user080522's user avatar
0 votes
1 answer
39 views

How would a gas flow switch react to falling pressure in the gas supply?

There's currently an ongoing discussion (not decision!) in Germany if households could be cut off from gas supply come winter, to make more natural gas available for industry. Of course media is full ...
mart's user avatar
  • 4,771
1 vote
0 answers
39 views

Understanding flow curves of an hydraulic directional proportional valve

In the picture below you can see the command signal to flow curves for a proportional valve I'm using. Since I'm using it to control the speed of a cylinder I was looking at the looped flow path ...
Landau's user avatar
  • 151
0 votes
2 answers
976 views

How to connect a 1/4 NPT pressure gauge to a schrader valve while being airtight

I need to attach this pressure gauge - https://www.amazon.co.uk/gp/product/B07CXM3ZGT/ref=ask_ql_qh_dp_hza - to a schrader valve with a pipe to measure the pressure. The valve has a 1/4 NPT thread. I ...
Pipistrelle's user avatar
0 votes
2 answers
31 views

Can you make a simple hand-operated pump using two check valves?

question is basically the title. I was wondering if it would be possible to connect a check valve on each end of a squeezable bladder in order to make a simple pump. The purpose would be to make a ...
Andrew's user avatar
  • 1
0 votes
0 answers
22 views

What is the lowest energy solution for emptying a drip irrigation water collector : a mono-stable solenoid valve or a bistable coupled to a pump?

I have a water collector I want to empty everyday for drip irrigation. It is controlled by a micro-controller. I have identified three solutions: Use a bi-stable electro-valve and a pump: advantage ...
lalebarde's user avatar
  • 101
0 votes
2 answers
121 views

Relief valve for "semi-closed" loop system (non-engineer warning :-)

My excuses in advance for the probably-bad wording of the question, I'm just an hobbyist without much knowledge in engineering. To the point I can't google for information on my problem since I don't ...
Joe's user avatar
  • 1
0 votes
1 answer
32 views

Can flow rate of a small gas flow be controlled by a valve that is opened and closed rapidly in a certain frequency?

Can flow rate of a small gas flow be controlled by a small solenoid valve that is opened and closed rapidly in a certain frequency?
David jones's user avatar
1 vote
1 answer
2k views

Head loss coefficient for a valve with respect to both the open position and flow rate

This question talks about the head loss coefficient for a valve, i.e., $K_{L}$ for $h_{L} = K_{L} V^{2} / 2g$ where $h_{L}$ is head loss. First, head loss coefficient for a valve with respect to the ...
J. Choi's user avatar
  • 121
3 votes
2 answers
423 views

Why do pneumatic valves need both a Safety Relay and an Air Dump to be safe?

If air dumps safely release pneumatic pressure from an industrial machine when an E-Stop is pressed, why is it also standard practice to cut electrical control power from the valves with a safety ...
Micah Lindstrom's user avatar
0 votes
1 answer
52 views

Is there any way to quantify the rate at which pressure is relieved in a reactor?

If a pressure relief valve is open, is it somehow possible to quantify the rate at which the pressure in the reactor will decrease?
HWIK's user avatar
  • 3
0 votes
0 answers
45 views

Which of these systems should reach a better vacuum?

I'm trying to find a cheap manual vacuum pump for a sample transportation container that carries oxidizable samples of thin-film magnetic materials. They already have a 15 nm Tantalum layer on top, so ...
user2934303's user avatar
0 votes
1 answer
38 views

Is there a valve that will only open when input pressure is above 3 atm including when the downstream pressure is also 3 atm?

I want to use an external gear pump to pump air into a combustor at a design pressure of 3 atm. Unless i use a valve that opens at threshold pressure there is no compression - the air exists the pump ...
Francis L.'s user avatar
1 vote
0 answers
34 views

Valve solution for mixing external air into a closed loop climate controlled air circulation system

I'm looking for an electronically controlled air valve solution which would provide a way to mix external air into a closed loop air circulation system used for climate control in an enclosure. The ...
Element Green's user avatar
1 vote
0 answers
45 views

What's the name of the valve that opens once pipes are mated?

I am building a wastewater system for my van (ie low pressure) and would like removable tanks for ease of emptying. I can shut off the inlet but would like to be able to drop them and automatically ...
Mike's user avatar
  • 171
0 votes
0 answers
39 views

Controlling flow through an output pipe

I wish to limit my flow through the output to a certain exact value. In this case to 10 lpm, what method or valve can I use to this task? At the moment the flow keeps on fluctuating between 10.1-11.2 (...
Anshuman Sinha's user avatar
0 votes
2 answers
180 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{\...
Tee's user avatar
  • 33
1 vote
1 answer
2k 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'...
benjarojas's user avatar
0 votes
1 answer
112 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 ...
Divyam Gupta's user avatar
0 votes
0 answers
122 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. ...
GeraltBlack's user avatar
0 votes
0 answers
36 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 ...
cheesus's user avatar
  • 101
0 votes
0 answers
29 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 ...
oorst's user avatar
  • 129
1 vote
1 answer
358 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 ...
Athena's user avatar
  • 11
5 votes
0 answers
381 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 ...
Oliver Nicholls's user avatar
0 votes
0 answers
48 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 ...
Albert Choi's user avatar