Subject: Step down regulators From: "Kelvin Smith" <KelvinSmith@untraveledroad.com <mailto:KelvinSmith@untraveledroad.com>> Date: Thu, 27 Jan 2000 13:53:28 -0700 Hello, I have a question about regulators. I am looking into replacing my blower and considering one with higher pressure output. The old one I assume had = a static of 7". I am looking at one with about 15" static. It was suggested that I use a "step down regulator" to get closer to the ~5" pressure for most of the windchests. I do not understand very well how a regulator = would be affected by higher input pressure. Except for the pedal, my whole organ has been fed through a main regulator that then fed regulators for each division. With the new blower I was hoping the main regulator could be set at 10" pressure (which is the pressure I want the tuba to be on) and then go down to 4 to 5 inches at the divisional windchests. Here are some questions: 1. Is the pressure in a regulator affected by a) just the weight on the regulator or b) does the input pressure affect it also? In order to regulate accurately, it seems that the weight ought to be the only factor. 2. If the input pressure is higher, the regulator would tend to fill up more with the same amount of opening at the curtain valve. Am I right to think that I can adjust the curtain valve to compensate for the higher pressure (the objective to keep the spill valve from opening). 3. How much difference can you get between static and regulated pressure with one regulator? I have another situation where I need to understand this. I have a blower to operate the pneumatics in my console combination action which puts out about 20" pressure (not much cfm of course). I doubt the solenoids will operate against that much pressure. I am anticipating the need for a regulator to reduce the pressure. I am trying to decide what would prevent me from getting whatever pressure I end up needing by building a small regulator with a small curtain valve so that not much air goes into it. Thanks, Kelvin

Subject: Re: [Residence Organs] Step down regulators From: <RDoer30176@aol.com <mailto:RDoer30176@aol.com>> Date: Thu, 27 Jan 2000 20:40:19 EST Hi Kelvin In general terms, a reg. with curtain valve does not care,within reason, = what the inlet prusure is. The reg. presure is controled by weight, springs or = both. For the consloe blower, a small curtain valve reg, would be fine. One say 8"by10" would do. A little larger would be better. In your case, if you are only needing to wind the tuba, maybe a separate blower would be better. But you would need another reg. 1 1/2 or 2 square feet. I have a windjammer blower on 15" 3 stage 120 volt 3" outlet. Not sure of = the cubic feet per minute but I think I can find out. Russ

Subject: Re: [Residence Organs] Step down regulators From: <GRSCoLVR@aol.com <mailto:GRSCoLVR@aol.com>> Date: Thu, 27 Jan 2000 21:17:04 EST Hi Kelvin--- I recently purchased a console regulator from a 4 manual A-S pipe organ,,,,supposedly the last console that they built. The console = regulator is 6X6 inches,,,,and has no curtain valve,,,it has a cone type valve = worked by a relatively thick pouch about 4 inches in diameter, and that with a = coil spring (adjustable) on the top of the cone valve/pouch assembly. This regulator is marked 10 inches on it,,however,,I adjusted it down to to 4 inches without any problems. The cone is about 3 inches in diameter. It looks like one that size could be made easily,,,,,I would think if it was designed to wind a 4m console it would be big enuf for about anything in = the console department. Hope this helps. Regards, ---Roc

Subject: Re: [Residence Organs] Step down regulators From: "Larry Chace" <RLC1@etnainstruments.com <mailto:RLC1@etnainstruments.com>> Date: Thu, 27 Jan 2000 22:38:19 -0500 Kelvin Smith raised some interesting questions about pressure regulation. In an ideal world, it is probably true that a regulator would always = output its specified pressure as long as the input pressure remains at least a little bit higher. Real life regulators, though, most certainly have a certain amount of imperfection, and that might well result in some amount of variation in = the output pressure as the regulator's valve(s) open and close. That effect seems likely to be increased with higher input pressures. Take an extreme example, for example: if the input pressure were 1 million PSI, and the output pressure were 3", then as the regulator decided to admit some input in order to maintain the output, the slightest opening of its valve would admit a stupendous blast of high pressure air, and that just can't avoid affecting the output. It was an extreme, but the principle is still there -- some amount of the input will affect the output unless the regulator is "perfect". Isn't there a quote from G. Donald Harrison in one of the Callahan books regarding statis regulators? He explained that Aeolian-Skinner was using them, set to produce an output that was just an inch or two higher in pressure than the output of the regulators up in the organ chamber. That way, the chamber regulators didn't have to deal with a large pressure difference. In the theatre organ world, it seems to be a general rule that the static pressure should be about 150% of the chest pressure in order to get a "good" tremulant, at least for Tibias. The high input pressure gives a = bit of a "bump" to the pipes when the regulator valve opens. I would suspect that for a more classic organ design that effect would be considered a defect and that static regulators would be a good idea if the blower pressure were considerably higher than the chest pressure. Kelvin -- why not try it each way and tell us the results?!? Larry Chace

Subject: Re: [Residence Organs] Appropriate chest pressure From: <GRSCoLVR@aol.com <mailto:GRSCoLVR@aol.com>> Date: Fri, 28 Jan 2000 17:14:59 EST Hi Kelvin--- You can make yourself a wind gauge very easily with a length of clear = tygon or plastic tubing. Say about 6 feet. Tywrap it around a old yardstick = with the 2 legs at the up side of the measuring lines. Fill the tube with water,,enough to get it to some inch marking exactly preferably. make some = kind of cork adapter for the other end of the tube to fit it to the = windchest hole. With note valve open, read the summation of the inches on the = measuring device,,,,ie, 3 inches up and 3 inches depressed, =3D6 inch wind. The size = of the tubing makes no difference at all,,,its the weight of the water that = does the measuring. Hope this helps, ---Roc

Subject: Measuring Wind Pressures. From: "Bruce, David" <David.Bruce@compaq.com <mailto:David.Bruce@compaq.com>> Date: Mon, 31 Jan 2000 09:07:18 +0800 There has been a thread recently on measuring wind pressures using a manometer (U-tube). In past experience, I have found that if you only open the valve for the pipe-hole where the manometer is plugged in, you can get a false reading (usually high). I believe this is due to the regulator valve opening to make up for the lost air, but the system is still sealed and the result is that the pressure in the chest is raised. By opening a second valve and letting it exhaust to atmosphere, you will get a much better idea of what the regulator is actually regulating to. The results I had in the past were with Wurlitzer copy regulators, running at 6", 8" and 10" pressures. Blower static was 17". The effect described above may have been a result of the difference between static and = regulated pressure. Any of our professional friends on the list have any comments? David Bruce

Subject: Re: Feed Line Sizing [was New room for the organ...] From: "Bernard C. Nordmann" <bcnordmann@cdmnet.com <mailto:bcnordmann@cdmnet.com>> Date: Mon, 21 Aug 2000 09:36:47 -0500 At 12:22 PM 8/16/00 -0500, you wrote: >> Run 12" pipe between the two? 6" ? > >If you need the capacity of one 12" pipe you will need at least >four 6" jobs to get the equivalent amount of air. >Why 'at least'? Because of frictional losses in the smaller windlines. It's the cross sectional area of the lines which determines the air carrying capacity, so four 6" lines are needed just for the basic air moving. To handle air friction, an additional wind line area is needed. In practice, however, most people (I believe) ignore the air friction contribution. I did in designing for my 3/13 Wurlitzer, using a 12" line for the 5 ranks in the main chamber (originally all flue pipes - bigger users of air) and relay and a 10" line for the 8 rank solo chamber (6 = ranks of reeds). Both chambers have a rock solid supply of wind; I can't get the reservoir/regulators to sag more than a tiny amount. Bernie Nordmann, St. Louis