A valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries ) by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings , but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. The simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid (gas or liquid) flow in one direction, but is pushed open by flow in the opposite direction. Valves are used in a variety of contexts, including industrial, military, commercial, residential, and transport. The industries in which the majority of valves are used are oil and gas, power generation, mining, water reticulation , sewage and chemical manufacturing . In daily life, most noticeable are plumbing valves, such as taps for tap water . Other familiar examples include gas control valves on cookers, small valves fitted to washing machines and dishwashers , safety devices fitted to hot water systems , and valves in car engines. In nature, veins acting as valves are controlling the blood circulation ; heart valves control the flow of blood in the chambers of the heart and maintain the correct pumping action. Valves play a vital role in industrial applications ranging from transportation of drinking water to control of ignition in a rocket engine. Valves may be operated manually, either by a handle , lever or pedal. Valves may also be automatic, driven by changes in pressure , temperature , or flow. These changes may act upon a diaphragm or a piston which in turn activates the valve, examples of this type of valve found commonly are safety valves fitted to hot water systems or boilers . More complex control systems using valves requiring automatic control based on an external input (i.e., regulating flow through a pipe to a changing set point) require an actuator . An actuator will stroke the valve depending on its input and set-up, allowing the valve to be positioned accurately, and allowing control over a variety of requirements.
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Premium Questions (42)
my son is 4 month old baby , he is diagonised of heart murmur with hole in heart of 6 mm. how XXXXXXX it is? he sweats a lot. is that a problem.what is the treatment for such hole? IS IT LIFE THREATENING, I AM WORRIED AS HE SWEATS A LOT.
Dear Doctor, I am taking cardiac medicines like a) Multaq 400 mg b) Cardace 2.5 mg c) Acitrom 2 d) Ecosprin 75 mg e) Dilgem SR 90mg f) Feuselerc and insulin for DM+ This is after my recent second open heart surgery...
having this pain in the middle of my chest and some time a little more on the right side of chest.I have a leaky Mitral valve prolapse but all my test indicated that I was just fine and noting was getting worse.What...
Just went to healthfair Normal everything except mild aortic regurgatation Should i worry?
Ecocardiography for my mother 67 have below mentioned indications:
Mitral valve - Grade-1 MVP (aml)
Doppler study - mild MR
LV - compliance - reduced
There is inflammation on one of the valve (could be...
Hi, I have CCA (Beals Syndrome), closely related to Marfans Syndrome. I am having shortness of breath and chest pressure, usually as a result of exertion. Inter tracheal echo 13 years ago showed my aorta on the high...
I have mitral valve prolaspse can i take levitra?
I am a 22 year old female. Sometimes I have a thump in my chest followed quickly by a softer thump. I had this when I was sitting down after eating. I have had a holter monitor about six months ago that showed...
What does mean bilateral basal exaggerated lung markings
I had make a Chest x-ray and that was the result. I wanted to know what does it mean??
And
Prominent aortic knuckle ?? Is it something wrong??
Hello Doctor,
I generally have a regular heartbeat. Lately, I experience an extra heartbeat, especially in the evening. I had a aortic heart valve replacement over a year ago. This recent extra heartbeat has been...
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Online Doctor Chat (7) - Valvular
Doctor : hi
User : how much is it for additional time?
User : sorry, it just might take a little to explain the symptoms
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User : here is the problem- it have had these passing out problems...
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User : i just have a question a murmur is a abnormal sound that may indicate?
User : what a stroke or valvular heart disease
Doctor : yes it is abnormal heart sound
Doctor : For Health purposes please...
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User : my mother has been operated last yerar of valve replace ment
Doctor : ok
User : and after one yerar she is having some problem
Doctor : i...
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User : Hi. This is regarding my father who is 56 years old and a known...
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Public Forum (224) - Valvular
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Hello, I am Shafi Ullah Khan, I have a sister and she is 15 years old. She is a heart patient from childhood. She has a minor problem of Heart Valves, they are not completely closed. Due to that heart problem, Her Lips and Nails colour is Dark Blue. We consult to many doctors but there is no good sign of result. We are very worried about her....
1 Answer
Ok so im a female and 16 i ve recently found out i need major heart surgury to replace one of my heart valves. I m really scared and not sure weather to go 4 it as my life is complete at the moment and i dont want 2 loose any of tht what would you do?????
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I have a heart Murmur and was wondering if I can go on rollercoasters? I have a heart murmur. Pulmonary Stenosis to be exact. I was wondering if I can go on Rollercoaster or can t. My parents always told me I shoudln t but I ve never heard a doctor tell me I can t. I have no idea. So, I was wondering if any of you can help me out here. Can I...
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hi my 14 year old son had an echo done and evrything came back normal except it says he has mild pulmonic regurgitation . what exactly does this mean and will it go away. he passed out in class the other day and we are going for 5 hour glucose test but could he have passed out from the heart thing . when the other findings on the echo came back...
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i am monika suffring for urethral stenosis .nex 15 dayes i trited by my Dr.today i am much better than first day of my tretment.what is the diet for me you sugest.i take medecine is tab axif200mg bd,tamflo0.4mgat bed time,looz at bed time,cap acovit M 1od.then what is my lifestyle & diet also.plsssss tell me.with regards.............monika.
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Faulty heart valve . A relative has been diagnosed with a faulty? heart valve, and needs an operation. She is 77 years old. Can anyone with accurate info. tell me what the procedure entails, and what the risks are please. Please no silly or ill informed answers.
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How does one get rid of a heart murmur? Is a murmur treatable ? what if someone is older, can they get rid of the heart murmur?
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what is the only valve on th heart with two cusps ? give me the name !i know what is bi cupid !
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once i was at school and all of a sudden my heart beat get really,not the kind that is normal, then my heart feels like its about explode then i cant breath and it hurt. i am 14,5 6. and weigh 124.What is it?:[
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What's a heart murmur??
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