Valve Definition and 218 Threads

Homework Statement Refrigerant 134-a enters the expansion valve of a refrigeration system at 160 psia as a saturated liquid and leaves at 30 psia. Determine the temperature and internal energy changes across the valve. Homework Equations Δu=cv*ΔT The Attempt at a Solution I'm...

Hello all, trying to figure this out. I work at a shipyard and operate/maintain the drydock. The discharge tunnel that flows water out into the ocean has culverts about 24.5' x 15.5' x 8'. Connected to the bottom of the culvert is a 48" pipe that goes to a gate valve of the same diameter. If I...

I am working on a problem trying to find out why a 0.010” orifice can be used to open a pilot actuated, spring return pneumatic 5/2 directional control (spool) valve, but a 0.0045” orifice only seems to work intermittently. The air system that I am working with is 100 psig. The air enters...

So the toilet in my parents bedroom is all hissing and annoying so I decided to try fix it for them. I bought a new cistern valve to replace the old one, when I removed the old one i noticed this thing circled in the attached pic. I'm not sure what it is used for except it prevents the...

Ok, so I am trying to build myself a small water tank (about 1 L) with 2 tubes coming from the top. The first one goes all the way down to the bottom (thus in the water) and acts as the outtake. The second one is an air intake where the air pressure is regulated, say 5 psi. Now, I want to be...

is it right to say that valve opening for both ball & butterfly valve is directly proportional to flowrate passing through it? say 100 m^3/hr at 100% opening 50 m^3/hr at 50% opening?? thanks in advance..

My company installed a number of balancing valves (Tour & Andersson, STAD) in a central heating system. These valves are used to measure the flow (in this case water). According to the valve's specs it should be installed with a certain distance of straight pipe both before and after the valve...

There is this talk in the New York Times about venting valves : What not use a proportional relief valve ?

What would happen if an amateur mechanic decided he wanted to adjust his valve timings outside the factory specifications and screwed up? What would happen? What can incorrect valve timings do to an engine?

http://en.wikipedia.org/wiki/Check_valve from the above wiki link I have understood basic concepts on Check Valves Suppose I Heat a gas ( air ) in a closed vessel. It's temp and pressure increase. As soon as the pressure reaches ( or exceeds??) the cracking pressure , the valve opens and...

Hi all. Probability definitely isn't my specialty, and I've run across this problem at work. There's one gate valve that isolates two 2400 psi hydrogen gas banks from each other, and I'm trying to find the probability that it fails in one year. I've done some digging and found failure rates...

Hello all - this isn't a homework question; it's a real problem I'm struggling to solve. Apparently I'm being a bit of a mechanics 'tard, so any help would be appreciated. I have a high pressure reservoir (~60MPa) sealed off from a low pressure area by means of a metal plate. The plate has a...

What are the main safety considerations during design of a pressure relief valve? and how would you go about diagnosing if they are incorrect? Is the following correct? Orifice diameter for a fixed pressure - How to diagnose if it wasn't correct? What effect would a incorrect system...

I need a valve that will pressurize a system, then leave the system pressurized for a time, then exhaust the pressure on command. I need it to be easily portable and quite small, and will run at pretty low pressures. What kind of valve would do this for me?

Is there a valve that can be set to open to let hot gas out at a certain pressure, and then close once the pressure drops back down? Edit: Sorry, I'm looking for a valve that will let the pressure build up to a high point, then open to release the gas until the pressure is released, then close...

Homework Statement build a circuit that open and closes the valve using, electronic components Homework Equations none known yet The Attempt at a Solution this is my first try

Hey guys, I have a set of rocker arms that I converted from a hydraulic to a mechanical adjuster and I am having problems with the adjuster screw I am currently using. Whats happening is that when the adjuster screw hits the valve lifter, its digging away at the top of the lifter causing a...

I need help designing a mechanism for quickly releasing water through a tiny hole on one end of a thin cylindrical pole by a switch/button/etc on the other end. I have thought of one way to do this and drew an illustration, which is in the attachment. But I'm not sure if when the bar is covering...

hi, im not sure that this is the correct category, or even the correct forum, but I am sure someone will answer my question, i am intending to build an airgun, which uses a bicycle pump to build up pressure inside a treacle tin (hahaha), and i need a valve, so that when i have compressed...

Hi guys, Right, here is the situation. Consider a long coil of pipe containing water with a thermostatic valve at the outlet and a valve (this is the valve in question) at the inlet. The inlet is gravity fed by a large reservoir of water and the question is this: as the water leaves the...

Hi all, Right, this may be a bit hard to explain but I'll do my best. Hopefully attached is a sketch of the situation. The water flows from the tank into the "rigid container" through valve (1). This tank is then heated until the water reaches boiling at which point the thermostatic valve...

Hi all, Need a bit of help with a problem. I have a 4 inch pipe (carrying water). On the end of this 4 inch pipe is a 2" orifice. Now flowing through this orifice is water at 50L/s at a head of 100m (790 GPM and 330 feet). Basically as you can imagine, there is a lot of energy behind this...

I have had trouble finding a source for a reversing valve manufacturer that carries a 12 vdc solenoid coil Any leads would be helpful. I have tried Danfoss, Ranco, and Parker, but to not avail. Thanks in advance for the help. D.

I am looking for a valve that will let water into a system, but will not let the air out. The valve however will be placed vertically with water entering from the top. Trying to add any water into my system has only created air bubbles. If you have any other suggestions on how to do so, or if...

Homework Statement Steam at 8 MPa and 500 C flows through a valve, where it exits at 100 kPa. What is the exit temperature? Homework Equations ? The Attempt at a Solution Looked up both pressures on the steam tables. Not sure how to correlate them as I have never used them before.

I'm not sure how to work this one... The spring on a safety valve can be compressed 15 mm by a load of 700 kg. In it's working position the compression of the spring is 22 mm. The combined mass of the valve, spring and spindle is 17 kg. Valve diameter is 80 mm. Determine boiler pressure...

Hi I hope that this won't be treated like spam or something. I just used search engine to find place where I can find people who may be interested to help me building something that I call "valve library". I started small website with intention to create online place where You can find all...

Hi, I'm a final year master's student doing a study on relief valve tailpipe design for my final year project. The system which the relief valve is fitted to is a high pressure breathing air gas cylinder (300 bar) on board a large ship and it vents to atmosphere via piping which can be...

Hi, 20m straight length horizontal pipe (60 mm internal diameter), steam flows at rate 0.5 kg/s, at midpoint there is a valve in the line. inlet pressure to this section of line is 5 bar (gauge), pressure at end of line is 3 bar (gauge). mass quality of steam is 0.8 and 2 phase flow occurs in...

Hello everyone Iam doing my M.S in aerospace engineering at Chennai, India. I require a high-speed operating pneumatic valve that can open and close more than 200 times a second. Kindly allow me to know if it is possible to acquire such a valve with these additional specifications also: > 2...

Hye everyone~ I am Jesse and I'm new to this forums :smile: and i really need your help so let's get straight to the prob.. can anyone tell me what are the choices i can use if i want to power up a solenoid valve installed in a hazardous area. I've heard about powering it thru system...

I need help with the following problem. I have attached a rough sketch showing what I'm looking at. Basically a popppet valve is closed over a vent. It is then pushed open by a force applied to the valve by the pushing rod. Their is a spring on the rod resisting this and providing a force...

if i wanted to figure out how much net force/torque is applied to a regular disk type valve in a pipe as a function of the pressure difference on both sides of the valve what would i have to do/where would i have to look?

Hallo, I'm looking for explanation for the fact that in many diesel engines we have two springs supporting the piston valves such that one is exterior and the other interior and they have opposite helical direction. Also if anyone have a link or any information it would be very helpful.

Homework Statement A nitrogen gas-liquid mixture is in a 20 cubic foot tank at a condition of 161 R with an initial quality of 0.1. Heating occurs at a rate of 10,000 Btu/h until the pressure reaches 100 psia. At this condition the BHE safety valve opens and maintains a constant pressure as...

Homework Statement You have your bicycle upside-down for repairs. The front wheel is free to rotate and is perfectly balanced except for the 16 g valve stem. If the valve stem is 34 cm from the rotation axis and is located 32 degrees below the horizontal, what is the resulting torque about the...

I need to determine if a valve can handle a flow rate of 50 GPM, this valve being: 2/2 Way, Normally closed, w/ 2-pilot control, and coupled solenoid. I also need to determine pressure drop... it is a burkhert model - 457361D the valve specs indicate: Cv = 35.1 pressure...

:!) anybody knows @ design of thermostatic expansion valve used in refrigeration and air conditioning.....?

A water based heating system is to be regulated by 2-way valves. How do these work exactly? Do they simply constrict the flow? Isn't it so that if a pipe is constricted, the velocity simply increases to maintain the flow? I mean, flow in must equal flow out.

the de laval valve comprehensively reduces the pressure, temperature and increases velocity of passing gases. but it is mostly employed in areas where gases are at very high speed. could it give same results for speeds as low as, say, 50km/hr?

I have been thinking about this a lot. It is about conservation of energy. A simplified analysis using Bernoulli's Principle for one-dimensional incompressible liquid fluids should be good enough to gain some understanding (at least for me). Let us also neglect gravitational effects. Assume...

Dear all, I'm a new user to Maxwell and to FEM. I am trying to do a magnetostatic analysis for a solenoid valve for finding inductance and force on the armature. I am facing few problems while making the simulation. 1. what value shall I assign for the source? (In the tutorial provided by...

Hey I was just wanting to know, for something like a guitar amplifyer what is the inputted signal connected to on the valve (cathode, anode, filament or grid) and also what the outputed signal is connected to. thanx

I'm in need of some assistance in calculating some flow vs pressure specifications, in order to make some changes to the system. I have a PRV valve that has a preset setting of: PRV NO.1 & 2 SET PRESSURE = 1034 KPA (150 PSI) @ 0.63 L/S (10 USGPM) Meanwhile the design criteria states the...

I'm trying to understand how a pressure reducing valve works. I'm puzzled: Water enters one side of the valve. Whatever opening the valve gives for the water to flow through, won't it come out with higher pressure? If the static pressure is less on the outlet side, doesn't that indicate that...

Homework Statement A large population of nominally identical "fail to close" control valves are put into service on the same day on similar installations. The number of valve failures per month N was recorded over time and shown to be given approximately by the following equation Calculate...

Homework Statement I am trying to find the probability that a valve will be able to undergo one cycle of demand? Given that a particular type of remotely controlled mechanical valve can be assumed to have a probability of not opening, when closed, of 0.02 and a probability of not closing...

Hi all. I am now looking for a valve whose opening can be quite accurately controlled. The size of the opening shall be quite small, around 3mm - 1cm? I am wondering if you know any valve that may suit my usage? Can the opening of a solenoid valve be adjusted using electric signal?

Hi all. I am doing a design of controlling a fluid flow. We have some fluid which is subjected to some weight, which will serve as the external force to drive the flow. The objective is to maintain a constant flow rate. Do you guys think I shall constantly changing the opening of a valve to...

Here is some information I have for throttle bodys: 60 millimeters is equal to 2.362205 inches = 17.52 square inches 65 millimeters is equal to 2.559055 inches = 20.56 square inches - (17%) 70 millimeters is equal to 2.755906 inches = 23.85 square inches - (36%) 75 millimeters is equal to...