loving@lanai.cs.ucla.edu (05/03/89)
I am looking for valves (for fluids) taht are electrically operated. Does
anyone out there know of a source for such a thing?
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Mike Loving loving@lanai.cs.ucla.edu
. . . {hplabs,ucbvax,uunet}!cs.ucla.edu!loving
-------------------------------------------------------------------------------henry@utzoo.uucp (Henry Spencer) (05/04/89)
In article <23526@shemp.CS.UCLA.EDU> loving@CS.UCLA.EDU (Mike Loving) writes: >I am looking for valves (for fluids) taht are electrically operated. Does >anyone out there know of a source for such a thing? Check out your local source for washing-machine parts. (A good big hardware store?) Probably much cheaper than getting them from orthodox hydraulic- part suppliers. -- Mars in 1980s: USSR, 2 tries, | Henry Spencer at U of Toronto Zoology 2 failures; USA, 0 tries. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
joec@Morgan.COM (Joe Collins) (05/04/89)
In article <23526@shemp.CS.UCLA.EDU>, loving@lanai.cs.ucla.edu writes: > I am looking for valves (for fluids) taht are electrically operated. Does > anyone out there know of a source for such a thing? Mike, Try visiting a landscaping business and see what they have in the area of underground sprinklers. These control water flow with a 12 volt supply. You can probaly get what you want for about $30. Regards, Joe
myers@hpfcdj.HP.COM (Bob Myers) (05/05/89)
>I am looking for valves (for fluids) taht are electrically operated. Does >anyone out there know of a source for such a thing? If you're looking for something simple, cheap, and you have no plans to run particularly obnoxious fluids through the valves, then I suggest you go to your local garden supply shop and ask where the underground sprinkler system stuff is. Bob Myers KC0EW HP Graphics Tech. Div.| Opinions expressed here are not Ft. Collins, Colorado | those of my employer or any other {the known universe}!hplabs!hpfcla!myers | sentient life-form on this planet.
haynes@ucbarpa.Berkeley.EDU (Jim Haynes) (05/05/89)
There's also Herbach & Rademan in Philadelphia.
haynes@ucscc.ucsc.edu haynes@ucscc.bitnet ...ucbvax!ucscc!haynes
"Any clod can have the facts, but having opinions is an Art."
Charles McCabe, San Francisco Chroniclejlohmeye@entec.Wichita.NCR.COM (John Lohmeyer) (05/05/89)
In article <23526@shemp.CS.UCLA.EDU> loving@CS.UCLA.EDU (Mike Loving) writes: >I am looking for valves (for fluids) taht are electrically operated. Does >anyone out there know of a source for such a thing? > I just installed a number of these in my lawn -- try Rain Bird sprinkler dealers (or their competitors) in your area. They operate off a fairly low voltage (24 VAC?) and can handle fairly high flow rates. They probably will not work on low flow rates (say less than 2 gal per min). ---- John Lohmeyer j.lohmeyer@wichita.ncr.com NCR Corporation ... uunet!ncrlnk!ncrwic!entec!j.lohmeye 3718 N. Rock Rd. The SCSI BBS (316) 636-8700 Wichita, KS 67226 Voice: (316) 636-8703
dente@els.uucp (Colin Dente) (05/05/89)
How about any shop that sells stuff for central heating systems (i.e. a large builders/plumbers merchant) - central heating systems are usually full of electrically operated valves (Though they are quite pricey (I think 8^()) Colin =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= | Colin Dente | JANET: dente@uk.ac.man.ee.els | | Dept. of Electrical Engineering | ARPA: dente@els.ee.man.ac.uk | | University of Manchester | UUCP: ...!mcvax!ukc!man.ee.els!dente | | England | These might work now, but then again... | |-----------------------------------------------------------------------------| | Well I know how to behave in the restaurant now, | | I don't tear at the meat with my hands. ....Well, not always.... | =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
rwb@vi.ri.cmu.edu (Bob Berger) (05/09/89)
For low flow low pressure applications, Edmund Scientific sells a 12 V solenoid operated valve at 2/$3.50 or 12/$12.95. They claim it's from the automotive industry, so you might check an auto parts store. I once needed a small pump, and found a windshield washer pump at KMART that was ideal for the job. Robert Berger rwb@vi.ri.cmu.edu --
lacasse@blaise.rand.org (Mark LaCasse) (05/09/89)
I'm not sure if washing machine, sprinkler, or other binary
solinoid valves would suffice the original poster, but
what I would like and can't find are PROPORTIONAL valves
of some sort. Something like a gate value with a stepper
motor attached. Something that can take water at 80 PSI.
(Which leaves out $100 each heating system zone valves.)
So whats the scoop on this?
Mark LaCasse qantel!hplabs!sdcrdcf!randvax!lacasse
c/o The Rand Corporation cbosgd!ihnp4!sdcrdcf!randvax!lacasse
1700 Main Street decvax!randvax!lacasse
Santa Monica, CA 90406
213/393-0411 ext. 1509 lacasse@Rand-Unixsukenick@ccnysci.UUCP (SYG) (05/11/89)
>>I am looking for valves (for fluids) taht are electrically operated. Does >>anyone out there know of a source for such a thing? Dayton, Angar Scientific, there are many other companies. Check the Thomas Registry for others. This book may be found in your friendly neighborhood science or engineering library.
larry@kitty.UUCP (Larry Lippman) (05/12/89)
In article <2011@randvax.UUCP>, lacasse@blaise.rand.org (Mark LaCasse) writes: > I'm not sure if washing machine, sprinkler, or other binary > solinoid valves would suffice the original poster, but > what I would like and can't find are PROPORTIONAL valves > of some sort. Something like a gate value with a stepper > motor attached. Something that can take water at 80 PSI. > (Which leaves out $100 each heating system zone valves.) A gate valve is not usually considered to be a proportional valve. The most common type of proportional control valves are: globe, needle, diaphragm, butterfly and ball. These valves are driven by an electric motor or by air (electrically controlled using an I/P transducer). A proportional control valve usually operates on a 4-to-20 mA DC signal, although voltage inputs are available. Proportional control valves are not cheap; you are looking at several hundred $$$ for a bottom-of-the-line valve (that is rated for industrial service). <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231, 716/773-1700 {att|hplabs|utzoo}!/ <> FAX: 716/741-9635, 716/773-2488 "Have you hugged your cat today?"
ron@hpfcmgw.HP.COM (Ron Miller) (05/12/89)
Re: Really want a proportional GATE valve? Huh? Gate valves aren't throttling valves. Gate valves are like flapper or butterfly valves, they are either OPEN or CLOSED but not really in between. Gate valves are used where minimal flow restriction is desired when the valve is open. They are expensive but pretty effective for isolation functions. If you want a throttling valve, buy a throttling valve. Recommend you try contacting a plumbing supply shop for the name of their valve vendor then contact the valve vendor for further contact names. It isn't going to be easy until you find the network of professionals who design or repair industrial fluid processing plants. Ron Miller
henry@utzoo.uucp (Henry Spencer) (05/12/89)
In article <2011@randvax.UUCP> lacasse@blaise.UUCP (Mark LaCasse) writes: >what I would like and can't find are PROPORTIONAL valves >of some sort. Something like a gate value with a stepper >motor attached... Good proportional valves are probably much more expensive than simple on-off valves, since the market is much smaller. As was suggested a while ago when this came up, one thing you can do is combine several on-off valves in parallel, with flow restrictors, to build a hydraulic digital-to-analog converter; it's not true proportional control but it might be close enough. -- Mars in 1980s: USSR, 2 tries, | Henry Spencer at U of Toronto Zoology 2 failures; USA, 0 tries. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
sparks@corpane.UUCP (John Sparks) (05/13/89)
<2011@randvax.UUCP> Sender: Reply-To: sparks@corpane.UUCP (John Sparks) Followup-To: Distribution: Organization: Corpane Industries, Inc. Keywords: In article <2011@randvax.UUCP> lacasse@blaise.UUCP (Mark LaCasse) writes: >I'm not sure if washing machine, sprinkler, or other binary >solinoid valves would suffice the original poster, but >what I would like and can't find are PROPORTIONAL valves >of some sort. Something like a gate value with a stepper >motor attached. Something that can take water at 80 PSI. >(Which leaves out $100 each heating system zone valves.) > >So whats the scoop on this? I don't know, but we've (Corpane) have been looking for such an animal for a while now. We have water cooled machines and would like our on-board microprocessor to control how much water is let into the system. So a stepper motor controlled proportional water valve is exactly what we need. We looked everywhere, I think we found one place that sold it but it was an outrageous price (somewhere around $1500). If anyone knows where we could find a cheaper version than that, Please help us out and tell us where. I guess our next step will be to build it ourselves. But we really aren't set up for such an enterprise. -- John Sparks | {rutgers|uunet}!ukma!corpane!sparks | D.I.S.K. 24hrs 1200bps [not for RHF] | sparks@corpane.UUCP | 502/968-5401 thru -5406 If a town has one lawyer, he starves; if it has two lawyers, they both get rich
phillip@bartal.CRLABS.COM (Phillip M. Vogel) (05/14/89)
In article <2011@randvax.UUCP> lacasse@blaise.UUCP (Mark LaCasse) writes: >I'm not sure if washing machine, sprinkler, or other binary >solinoid valves would suffice the original poster, but >what I would like and can't find are PROPORTIONAL valves >of some sort. Something like a gate value with a stepper >motor attached. Something that can take water at 80 PSI. >(Which leaves out $100 each heating system zone valves.) > A good (and cheap) way to handle this was suggested by someone else a couple of months back when this was discussed (it seems to come up regularly). The plan is this: Get a number of on/off valves, and add flow restrictors to them. The flow restrictors should be set such that the flow through each valve is twice the flow through the previous valve ie. 1gpm, 2gpm, 4gpm, 8gpm, 16gpm, 32gpm, 64gpm etc. What you have then is a digital to analog converter which puts out water instead of electricity. We all learned that electrical current through a conductor is analagous to water flow through a pipe, so I guess this is a natural extension of that theory. BTW, if you need finer control, you could start the binary series at a lower flow rate (1/4 gpm, 1/8 gpm, etc.). It really doesn't matter where you start as long as the rates douple for successive valves. Another advantage to this is that once the flow restrictors are set up, you will have precise and PREDICTABLE flows. Wit a proportional valve connected to a stepper motor, you will have to do a lot of experimentation to determine the proper settings for desired flow rates. Sorry for the long posting, but I hope it helps. Phillip -- Phillip M. Vogel, President | #include <standard_disclaimer.h> Bartal Design Group, Inc. Englewood, NJ | (201)567-1343 FAX:(201)568-2891 UUCP: killer!crlabs!bartal!phillip | Domain: phillip@bartal.crlabs.com ^^^^^^of questionable reliability these days
brianr@tekig5.PEN.TEK.COM (Brian Rhodefer) (05/16/89)
In article <2011@randvax.UUCP>, lacasse@blaise.rand.org (Mark LaCasse) writes: > I'm not sure if washing machine, sprinkler, or other binary > solinoid valves would suffice the original poster, but > what I would like and can't find are PROPORTIONAL valves > of some sort. Something like a gate value with a stepper > motor attached. Something that can take water at 80 PSI. > (Which leaves out $100 each heating system zone valves.) Someone already mentioned the "hydraulic DAC" approach, so I'll offer another whimsical translation of electronics technique to the water world: the hydraulic switchmode buck converter! Find a large tank somewhere. A possibility would be a defunct hot water heater whose element is shot, but doesn't leak at the stipulated pressure. Plug up its normal (hot) outlet. Connect its cold inlet through one of those binary solEnoid valves, to the water supply. If significant lengths of plumbing are involved, you'll need a healthy standpipe on one or both sides of the valve. Take your output either from the "inspection drain", or tee it from the the inlet, hopefully through a lengthy pipe. Drive the solEnoid valve with either a fixed frequency, variable duty cycle ON/OFF control train, or a fixed pulsewidth, variable frequency one. The ON and OFF pulsewidths should be longer, by at least an order of magnitude, than the operating speed of the valve. You can read in Circuit Cellar Ink all about how such a system can be driven by a relatively straightforward controller running a multitasking operating system, using as little as 32K of RAM. Or, if you're willing to work with your windowshades down, you might use a dual op-amp instead. Brian Rhodefer
larry@kitty.UUCP (Larry Lippman) (05/16/89)
In article <631@corpane.UUCP>, sparks@corpane.UUCP (John Sparks) writes: > >I'm not sure if washing machine, sprinkler, or other binary > >solinoid valves would suffice the original poster, but > >what I would like and can't find are PROPORTIONAL valves > >of some sort. Something like a gate value with a stepper > >motor attached. Something that can take water at 80 PSI. > >(Which leaves out $100 each heating system zone valves.) > > I don't know, but we've (Corpane) have been looking for such an animal for a > while now. We have water cooled machines and would like our on-board > microprocessor to control how much water is let into the system. So a stepper > motor controlled proportional water valve is exactly what we need. > > We looked everywhere, I think we found one place that sold it but it was an > outrageous price (somewhere around $1500). If anyone knows where we could > find a cheaper version than that, Please help us out and tell us where. > > I guess our next step will be to build it ourselves. But we really aren't set > up for such an enterprise. My organization frequently uses proportional control valves for various chemical instrumentation projects. Most of the valves we use are off-the-shelf chemical industry control valves which require a 4-to-20 mA actuation signal (i.e., 4 mA = closed, 20 mA = fully open). However, there have been a few projects where we did not wish to use an such an off-the-shelf valve because of size considerations, and because we wished to use a stepper motor and remain all digital for more precise control. Here is how we did it: 1. First, begin with a bellows valve intended for metering service (actually a globe or needle valve will also work). In one particular application we used a Nupro (a Swagelok company) bellows valve. Nupro is the cadillac of valves; lesser quality valves should suffice for water control applications. 2. The above valve required about 2-1/2 turns from fully closed to fully open. To limit travel of the valve, use a mechanical limit stop assembly. We used a device made by Winfred Berg, Inc. which cost about $ 100.00, and which has an adjustable stop range from about 30 to 900 degrees. Couple the limit stop assembly to the valve. 3. Provide a friction clutch between the limit stop assembly and the stepping motor. Again, we used Berg for this item. 4. Connect the stepping motor to the friction clutch. We used a Superior Electric Slo-Syn (tm) series stepping motor. While the above items cost us several hundred dollars, with some luck you can probably find them surplus for pennies on the dollar - except for the limit stop assembly, which is not too common. With some ingenuity one can probably design some type of multi-turn limit stop assembly for a few dollars in parts. The clutch is optional; you can use the inherent torque limiting of the stepper motor to limit rotation. The nice part of the above design is that no feedback pots or limit switches are necessary. The limit stop assembly protects the valve from over-travel, and the clutch protects the stepper motor against overheating. In operation, the microprocessor first "initializes" the valve on powerup by pulsing enough steps to close the valve plus some extra. Since the microprocessor had no idea where the valve position was upon powerup, we gave it something like the full open-to-close steps (around 500) plus an additional 50 steps. This _assured_ the system that the valve was closed AND against the closed rotational limit stop. Since we were now initialized, the microprocessor merely kept track of open and close steps (actually 1.8 deg increments) to see where the valve was. As long as the algebraic sum of valve increments is maintained, there is no need for any feedback devices. I'm certain that many Net readers can construct the above scheme on a low-budget basis. The least expensive item should be the stepper motor; just look for a junk LA-36 Decwriter or equivalent. :-) <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP {allegra|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> TEL 716/688-1231 | 716/773-1700 {att|hplabs|utzoo}!/ \uniquex!larry <> FAX 716/741-9635 | 716/773-2488 "Have you hugged your cat today?"
greg@bilbo (Greg Wageman) (05/17/89)
In article <28@bartal.CRLABS.COM> phillip@bartal.CRLABS.COM (Phillip M. Vogel) writes: >In article <2011@randvax.UUCP> lacasse@blaise.UUCP (Mark LaCasse) writes: >>I'm not sure if washing machine, sprinkler, or other binary >>solinoid valves would suffice the original poster, but >>what I would like and can't find are PROPORTIONAL valves >>of some sort. Something like a gate value with a stepper >>motor attached. Something that can take water at 80 PSI. >>(Which leaves out $100 each heating system zone valves.) >> >The plan is this: Get a number of on/off valves, and add flow restrictors >to them. The flow restrictors should be set such that the flow through >each valve is twice the flow through the previous valve ie. 1gpm, 2gpm, >4gpm, 8gpm, 16gpm, 32gpm, 64gpm etc. What you have then is a digital to >analog converter which puts out water instead of electricity. We all >learned that electrical current through a conductor is analagous to water >flow through a pipe, so I guess this is a natural extension of that >theory. Some potential problems with this setup: 1) It will be large and require quite a bit of plumbing. 2) It will be noisy. Both the electrically-operated valves and the flow restrictors will add their share of noise (it will tend to sound like the fill cycle on a washing machine. 3) The current draw at full-flow will be quite high, compared to a single-valve setup, since all 'n' valves will be on. Depending upon the application, you may not care about any of the above; on the other hand, this setup would not be acceptible inside the wall of your typical domestic bathroom for example (especially times two; one for cold and one for hot!). >Another advantage to this is that once the flow restrictors are set up, >you will have precise and PREDICTABLE flows. Wit a proportional valve >connected to a stepper motor, you will have to do a lot of experimentation >to determine the proper settings for desired flow rates. The flow will be predictable only if the input pressure is relatively constant, which may or may not be true depending upon application. The stepper-motor approach is *much* better if you use feedback. There's a company called Omega which publishes thick, glossy catalogs of flow-control sensors. Put a flow meter downstream of your stepper-controlled proportional valve, and read the amount of flow you're getting. Then adjust the valve up or down accordingly. A little care in avoiding oscillation, and you will get precise, variable control from a single valve. You will still need two for hot/cold mixing applications. A thermocouple downstream of the mixing point can also give you temperature feedback, which you can combine with your flow-rate data for accurate temperature and flow control. Longish .signature follows. Skip now. Greg Wageman DOMAIN: greg@sj.ate.slb.com Schlumberger Technologies UUCP: ...!uunet!sjsca4!greg 1601 Technology Drive BIX: gwage San Jose, CA 95110-1397 CIS: 74016,352 (408) 437-5198 GEnie: G.WAGEMAN ------------------ "Live Free; Die Anyway." ------------------ Opinions expressed herein are solely the responsibility of the author.
kluksdah@enuxha.eas.asu.edu (Norman C. Kluksdahl) (05/18/89)
In article <631@corpane.UUCP>, sparks@corpane.UUCP (John Sparks) writes: > > I don't know, but we've (Corpane) have been looking for such an animal for a > while now. We have water cooled machines and would like our on-board > microprocessor to control how much water is let into the system. So a stepper > motor controlled proportional water valve is exactly what we need. This brings to mind a problem encountered by my father-in-law when he was working on biomedical instrumentation for the Air Force (actually, for NASA). One experiment which flew on Skylab required digital control of a vacuum chamber. I think the idea may have some possibilities with your application. It works like this-- take 3 or 4 (or more) electrical ON-OFF valves, and connect them in parallel to a LARGE inlet manifold. The key is to have very little pressure drop from the first valve to the n'th valve, and to have lots of capability for flow. Follow each valve with a manual valve, which you then adjust for a given flow. The first manual valve is adjusted for n gallons per minute, the second for 2n, the third for 4n, etc. By selecting which valves are on, you can control the total flow. The output of the manual valves is then fed to an output manifold, again large. ASCII graphics of this: ------| e valve 1 |---|m valve 1|--------- | n gpm | | | |-----| e-valve 2 |---|m valve 2|--------| | 2n gpm | | | ----------------| e valve 3 |---|m valve 3|---------------------- ----------| 4n gpm |-------------- inlet manifold | | outlet manifold etc. This may provide at least some measure of digital control. Hope it helps. ********************************************************************** Norman Kluksdahl Arizona State University ..ncar!noao!asuvax!enuxha!kluksdah alternate: kluksdah@enuxc1.eas.asu.edu standard disclaimer implied
larry@kitty.UUCP (Larry Lippman) (05/21/89)
In article <137@enuxha.eas.asu.edu>, kluksdah@enuxha.eas.asu.edu (Norman C. Kluksdahl) writes: > It works like this-- take 3 or 4 (or more) electrical ON-OFF valves, and > connect them in parallel to a LARGE inlet manifold. The key is to have > very little pressure drop from the first valve to the n'th valve, and to have > lots of capability for flow. Follow each valve with a manual valve, which > you then adjust for a given flow. The first manual valve is adjusted for > n gallons per minute, the second for 2n, the third for 4n, etc. > By selecting which valves are on, you can control the total flow. The output > of the manual valves is then fed to an output manifold, again large. For the above scheme to work on an _accurate_ repeatable basis without the use of a flow rate feedback sensor, it is necessary that the pressure on the inlet valve manifold be regulated. In addition, error will be introduced if the "backpressure" presented to the outlet side of the valve manifold changes - as a result of increased flow and/or other conditions caused by delivery of the fluid. The point to bear in mind is that flow rate across an orifice varies as the square root of the differential pressure across the orifice. You can calibrate an orifice (i.e., an adjustable valve) to deliver a given flow rate ONLY for a given differential pressure; if this differential pressure changes due to inlet pressure and/or outlet backpressure conditions, so will the flow rate. In industrial/chemical process applications, flow rate is never set solely through a valve without feedback either from a flowmeter, or from an ultimate process variable (like temperature, in a mixing application). <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP {allegra|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> TEL 716/688-1231 | 716/773-1700 {att|hplabs|utzoo}!/ \uniquex!larry <> FAX 716/741-9635 | 716/773-2488 "Have you hugged your cat today?"