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Questions tagged [valves]

119 questions
20
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Sizing a pressure safety valve for two-phase flow

I understand that valves in two-phase vapour / liquid were sometimes sized by considering the required vapour and liquid flow rates separately, and then adding the results together. But this is now considered an outdated practice. I have also heard…
SecondVector
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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 the alleged effectiveness of the valve is based…
James
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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 roughly 1/2”/12mm (female, threaded) which is just…
Oliver Nicholls
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2 answers

For a small valve in a fluid system, what is the relationship between pressure and flow rate?

The specific example I have in mind is a car tire with a small leak in it. As the pressure increases, does the outflow of air increase linearly, i.e. $v\propto P$, or does it have some more interesting behavior?
Chris Mueller
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4
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1 answer

LO/LC, CSO/CSC Valve Definition

Does any one here know of an authoritative source (ASME, ISA, NFPA, OSHA, etc..) that gives a definition for the following in one of their standards or codes and the number for that standard or code: LO (Valve Locked Open) LC (valve Locked…
Jrican
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4
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2 answers

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 and flow of the system. I can tune the max line…
Brian Collins
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2 answers

Solenoid valve pressure drop

I'm designing a solenoid valve for an automated irrigation project that I'm working on. After having looked at some designs, I have a question. For most of the designs I've seen, the orifice is smaller than the pipe diameter. Wouldn't this reduce…
azhamn
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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 a certain value. The use case is a system with a…
Kalle Richter
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4
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4 answers

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 bottle, a connector, valves and diffusors and…
Kalle Richter
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3
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1 answer

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 If it matters, the valve is used to control water…
user16
3
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1 answer

Service Life of a Flashback Arrestor

First of all, I would like to know about the service life of a flashback arrestor. In my laboratory, I got three flashback arrestors {WITTgas RF53N(1/4”NPT-F), Brass} from the ex-students who used those items in 2012 and already finished their…
Shubhra Kanti Das
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4 answers

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 relay? This would be useful if the air dump failed,…
Micah Lindstrom
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3
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1 answer

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 water always keeps recirculating. The system uses…
NoumanQ
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3
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Does this exist? -Sliding Fluid Restrictor -Solenoid Valve -Ball Valve

I am trying to come up with a way to restrict beer flow using a valve that does not cause foam. I have found that a solenoid valve causes a change in the direction the beer must flow and this sharp change through a different size opening creates…
Peace
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3
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2 answers

What type of liquid flow control could this device use?

I am trying to figure out what kind of device is being used to stop and start the flow of liquid inside this device. Below is a link to the device. It looks too small to be a solenoid or a pump. How else would they do it? I heard somewhere it may be…
JoeTaylor
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