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SurfLung

Contributor
Messages
195
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Location
Central Minnesota
# of dives
500 - 999
Tornado 3000-4-3
Possibly a Jewel That Just Needs Cleanup and Service?
Tornado01.jpg

Tornado02.jpg

- This compressor has been for sale for almost a year. Back then, I was looking for a new project and gave the seller a low-ball offer... It just didn't look like much in the pictures. The seller declined but also remarked, "This is a real scuba compressor and it runs. These things go for thousands of dollars. My price is almost nothing already." So just recently I came across his advertisement again and he had lowered the price to what I offered before. I won't say the price. I WILL say it was an extreme bargain... Especially after I went to pick it up and could look it over in person. The pictures did not do it justice. I took the photos above and I don't know if my photos are any better. For one thing... Its alot BIGGER than I expected. I have seen photos of smaller Kidde compressor units being hefted with one hand. I estimate this whole thing is 3 feet long and about 100 lbs.
Tornado03.jpg

- The pump unit is a 4-Stage "Slant Type" Kidde military surplus unit. I've seen online manuals that suggest it is capable of 4 cfm if run at 3750 rpm. This installation is direct drive with a 3.5 HP, 220 volt, 3500 rpm motor so I expect it pumps 3-3.5 cfm. And rated for 3000 psi. The "Tornado" model of complete compressor was advertised in Skin Diver magazine back in the '60s and manufactured by High Pressure Engineering out of Oklahoma City, OK. This particular unit was used in a fire department to fill SCBA tanks. It is covered with oil and dust... I'm hoping it was retired from service simply because it needed servicing and they couldn't find anyone to do it. I turned the fan blade (which is direct drive) and it moves freely... So hopefully no pistons are seized up.
- First order of business is to clean it up so I can look it over closer and see what I've got. Second is to see if the pump can be rotated and pistons go up and down without causing damage. And third is to see if the electric motor is in working condition. I think I'll take the whole thing to our local electric motor repair service for inspection, wiring, and test run. :D
 
like I posted on the VDH forum, I'd be shocked if the motor itself was bad. Those things very rarely fail. It's possible, but unlikely. Getting it wired properly is ideal though.

What's your goal with it?
 
Actually I'm a lot less concerned with whether the electric motor works than with whether the compressor head works. I can get a working motor easier than a compressor head. Over the weekend I did some more cleanup and took the fan off so I could put a wrench on the drive shaft. Turning the drive shaft with my finger over the air intake port, it sucked my finger hard against the port. So, I'm thinking the compressor head is working! That's GOOD news.

What's my goal? Well, I had a lot of fun rebuilding and learning my RIX SA-3 compressor... And I get alot of satisfaction from having it run at peak efficiency... A true 3.0 cfm fill rate. But there's nothing left to do with it. So, I started looking around for a dirt cheap used compressor to fix up. I've made several extremely Low Ball offers that were turned down. I was figuring, I don't want to spend alot just to have something to play with. Anyway, I think I may already have got my money's worth out of this new/old Tornado... I've learned so much and enjoyed it so much.

My goal is to get it running at peak efficiency pumping good clean breathing air. After that, I might hook it up in parallel with my RIX and pump air at 6-7 true CFM! :)
 
wear your hearing protection, those little things are loud when running at full RPM. Also make sure that when you combine them that you have separate filtration for the Kidde to get rid of the oil and water before they go together into final filtration and have check valves between the two
 
This Thing Really SUCKS!
- Well, since my original post, I've done some cleaning up and a LOT of examination and figuring... But a brief conversation with Mr. Shelden of Shelden Sports really explained a heck of alot. Mr. Shelden was VERY familiar with this particular Tornado compressor. It's quite a bit different from my RIX SA-3... Seemingly a lot more complicated. I took some notes after I got off the phone:

- So I asked him about some of the known mysteries:
1. The tube with the glass sight tube full of oil is the oil reservoir. The black top is both, an over pressure
release AND the fill cap. The oil goes out the bottom to the front of the Kidde which is the oil pump.
From there is a return tube that goes back to the top of the oil reservoir. Further on the oil... There's a
brown plastic vent tube coming out of the 4th stage that will give a spurt of air with oil and moisture
mist when the compressor is powered down.
2. The black tower is the moisture accumulator which drains automatically when you shut down the
compressor. I told him about the stuff under the platform... There's a T with one side being a pressure
switch that looks like a gauge and the other side looks blunt end or pressure release. This T is what both
the moisture accumulator and the filter towers bottom plumbing is connected to. Jim asked me to send
him pictures of this set up.
3. The filter tower is a hydraulic accumulator. He says to re-pack it 2/3rds 13X Sieve on the
bottom and Activated Charcoal on the top.
4. Now the plumbing from the top of the filter tower has a pressure gauge, some sort of view port, and a
rectangular section with a faucet knob on top and an arrow indicating direction of flow on the side. Jim
thought this might be a back pressure regulator. Again, I'm supposed to take some photos and send
them to him.

The Oil System...
Tornado06.jpg

- While cleaning, I traced the oil lines and the return line actually comes out of the back of the compressor. The top of the oil sump has a little screen in the center. I unscrewed it and it definitely looks like a pressure relief of some sort.

The Automatic Moisture Drain...
Tornado04.jpg

- There's an instruction sticker on top of the switch box and I managed to see the print impression where the printing itself was rubbed off. AND,just like Mr. Shelden said, the system is supposed to drain moisture automatically when you turn off the compressor. I can't see how this works but the picture shows a pressure switch that looks like a gauge with the face turned the other way. The blunt end of the T fitting may be the release mechanism.
- The instruction said to drain moisture after every hour of continuous operation and to do so by turning off the compressor. In addition, if the compressor won't be used again for at least 4 hours, you should turn it on again for 10 secs and then off to blow off any remaining moisture.

It Really Sucks...
Tornado05.jpg

- Kind of an elegant design for the air intake filter. This one obviously hasn't been changed or at least cleaned for decades. It's about a 1/4" thick pad of filter material. Low profile and integral with the 1st stage piston top. I hope I can get a new filter pad. If not, I can screw on a Solberg.
- I wanted to see if the pistons were pumping freely or froze up so I took off the fan so I could get ahold of the drive shaft with a wrench. Then I rotated the drive shaft with my finger over the intake port... WOW! It sucked my finger tip hard against the port. So, it looks like the pump itself is intact and functioning!
- The fan itself is worth commenting on. It has a spring-type shock absorber (looks like a pull cord recoil spring). The original spec for this compressor is 3750 RPM and with a direct drive motor it must rev up to that pretty fast. I'm taking it that the coil spring lets the fan have a little gentler run up to full speed? The motor is rated for 3500 rpm so, a little slower than what the compressor can handle.
 
- Hey I just got off the phone with Jim Shelden (last night). He actually ran my exact same Tornado compressor many years ago. He said this Slant type 4 stage Kidde pump is the original 1947 patent upon which the later 4 stage Kidde compressors were based. This one is a heavy duty workhorse. He said he had two of them running side by side in his dive shop for 30 years... Running day in and day out, kept his storage/cascade tanks full, etc.
- He said these compressors have a 4:1 safety factor... He has seen them run as high as 8000 psi with no problems AND if I keep mine under 3000 psi this thing will run forever.
- Here's how the auto drain works. It has nothing to do with the pressure switch and plumbing under the platform. It's all part of the Kidde 4th stage design. When you turn off the compressor, it automatically drains pressure and moisture from the fourth stage. Moisture that had accumulated in the condenser gets pushed back to the 4th stage by pressure and drains out there. So, just fill a tank for 20 minutes and turn off the compressor... Moisture will drain. Hook up another tank and turn it on again. Fill it up and then turn it off to drain again.
- Now the stuff under the platform: It's apparently just set up so as not to over pressurize. The switch is set for something I can't see. But on the other end of the T is an over pressure valve that's set for 2900 psi. So, one or the other will either shut it off or release pressure. I just bet the Switch is set for the pressure of the fire department tanks. They'd just turn it on and let it run until it filled a tank to full pressure and shut itself off... Which would drain the moisture. A back pressure valve (or PMV) would keep the tank from losing pressure until they closed the valve on the tank. I bet that up on top knob is nothing more than a bleeder.
- I asked about building pressure fast to minimize hammering. He said the Kidde will never hammer. As for building pressure fast, he said if you plugged up the 4th stage it would reach 5000 psi by the 3rd revolution! Cripes!

- Jim Shelden was building Scuba compressors from Kidde pumps for decades. He used to buy used ones from the military by the crate load. I sure feel fortunate that he has spoken with me on the phone and given me so much information and advice.
 
@SurfLung of note, peak efficiency does not mean peak speed. Peak efficiency will be considerably slower than top speed, no different than MPG's on your car. With your Rix, you were running at peak speed with a lot of losses so you were a lot less efficient, but if you are looking at true efficiency of the pump the name of the game is minimize losses, then find out where the power/heat/cfm balance out.

PMV's also function as a check valve, but that is not their primary purpose, the FD would have had a check valve on the fill whip somewhere to keep the tank from bleeding back. The PMV is to knock moisture and various other bad stuff out.

Looking at the drawing, the final stages aren't floating so there won't be any hammering during startup, however for filtration/condensation you need to build pressure somewhere before it gets out of the condensers and filters. Not a lot of dead space in there so 5k psi by the 3rd revolution is unsurprising.

For anyone curious about any old threads and info from Jim on these compressors, check posts from @frogman62
 
More Gems from Jim (Shelden)
Tornado07.jpg

- "The brown tube is attached to the Oil Safety and also functions as the Auto Drain tube. Exactly as designed. Turn off the compressor after every tank fill (20-30 minutes)". Pressure will force moisture back from the condenser tower and drain it thru the brown tube. When you're done using the compressor, you give it one more moisture draining blast by turning it on for 10 seconds and then off again to trigger the Oil Safety and Auto Drain again.
Tornado08.jpg

- "The other picture (above) is the relief valve, in case the pressure switch fails to shut off the compressor". This relief valve has 2,900 psi written on the side of it.
Tornado09.jpg

- This is the back side of the pressure switch. AntiqueDiver told me the other side is actually the front. It comes off to reveal adjustment screws so you can set the pressure that you want to compressor to switch off at.

I think this Tornado compressor is set up for the simplest operation by a fire department where all of the SCBA cylinders are the same operating pressure. All an operator has to do is hook up a tank, open the valve, and turn on the compressor. When the pressure reaches "full", the pressure switch will shut down the compressor, which will also drain the moisture from the system.
 
Tornado Update 5/31/19
- I've brought the entire compressor up to an electric motor repair service we use for our work shop machines. It was previously hard wired so it needs a power cord and 220 volt plug to be able to plug into my drier outlet at home. They'll also check the motor out for good operation.
- In the span of barely a week, I have gone from knowing nothing about this compressor to having a pretty good grasp of it... Thanks to Jim Shelden. I'm ready to turn it on as soon as I get it back from the electric motor shop. But I've got to slow down a little now and make sure I do some other necessary activities as follows:

1. Finish cleaning it up. I've gone over it with hot water and dawn detergent twice now. And you can still see dirt in my photos. This thing was filthy with an oil film and dust. I've gone at it gently with toothbrush and rags... And will just put a little more time into it.
2. The "elegant" intake filter needs attention. Jim said I should take the felt filter media out to avoid any of it getting sucked into the compressor. He said I can screw on a standard intake filter like the Solberg I put on my RIX, into the intake so that's what I'll do.
3. The Moisture Accumulator (black tube) and filter tower (chrome tube) are made of steel and should not have any metal fatigue (like aluminum ones). But they may have some rust inside. AntiqueDiver Bill recommends I get a well lighted look inside to be sure these parts are up to running at 3000 psi.
4. The filter media needs to be replaced. Jim says bottom 2/3rds 13X Sieve and top 1/3 Activated Charcoal.
5. The pressure gauge on top of the filter may need replacing... The glass is broken.
6. The moisture sight glass on top of the filter needs some new moisture indicator paper.
7. The back pressure valve (I think thats what it is anyway) and open/close knob needs checking out and figuring of how it works.
8. The compressor oil needs to be changed.

- I may also need some new plumbing... A fill whip, check valve(s), PMV pressure maintenance valve or BPR back pressure regulator, maybe a bleed valve. Anyway, this stuff is all part of the fun if the core 4-stage Kidde compressor turns out to be working well.
- I will keep you posted of my progress but it won't be coming at you as fast as it has during this first week of ownership. :)
 
@SurfLung on cleaning it and keeping it clean, go for steam!
I got one of these to clean the engine bay in my '51 pickup truck and it worked wonders cleaning up my Hamworthy compressor that had a lot of similar type residue on it that you're describing. They have cheaper handheld ones as well. They do brilliant double duty for cleaning things at home like grout, baseboards, counters, couches, etc. since the steam rehydrates everything so you can wipe it away.
https://www.amazon.com/Wagner-Spray...team+pressure&qid=1559583259&s=gateway&sr=8-7

You had mentioned using this in parallel with your Rix. Can you draw an "ideal" layout of what you are looking to do with filters, whips, etc which may help on the PMV, check valves, etc? May be cheaper/better to use a quick disconnect of some variety to allow you to T the two compressors in and minimize duplicate purchases of the expensive stuff like PMV's and whips
 
https://www.shearwater.com/products/swift/

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