Having his own compressor

[ekarais]

I don't know how you manage fill in your bottles during a diving trip. But if you go with your own boat for a few days away form any diving center like myself than you need your own compressor. That's the reason why I've decided to bu a compressor about 10 years ago (or I could have bought 10 bottles).

I feel independent. My compressor gives me freedom.

Nowadays my freedom is over. Because I have an oil leakage problem and can not get pressure more than 140 bars and oil is everywhere. This is a Walter Kidde compressor (ex-army equipment, you know it) I've assembled it myself with a gas engine, put two filters one for collecting the moisture and the other with 3 stages filled with carbon and silicagel. It has worked perfectly years. Now I have find where the leakage comes from and fix it. Unfortunately don't have spare parts.

Kidde owners, can you help me?

Efe

 

[pescador775]

Ekarais, these three stage pumps are fairly cheap in the US. In fact, there is one for sale by 'Bargain marge' on EBAY. Just type in the words 'SCUBA compressor' and look for the sale. Or, look here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1300&item=3688339612&rd=1

I don't have any parts for three stage Kidde compressors. It sounds like your oil pump is bad, probably needs new seals. Did you say that you fixed it but need parts?? These pumps are similar to the four stage type that I have but turn in the counterclockwise direction. My spares are all clockwise pumps. Moreover, it is likely that low oil pressure caused failure of the third stage resulting in blowby and low output pressure. It could also mean bad valve springs. I mean, 10 years? It could be a lot of things. If ruined, the entire stage would have to be replaced. I mean, simply replacing the oil seal won't help. The front seal, incidently has a US part number, SAE (not metric). I can give you a part number but I really think you need to define the problem more accurately. Buy a new compessor and keep the old one for parts.

You could probably get a compressor from bargain Marge (protecair.com) for about USD 300-350.

 

[ekarais]

Pescador, Thanks for your answer. My compressor has four stages. The leakage comes from the seal between the 1st cylinder and man body. It is a metal seal but broken.

I've checked ebay. Unfortunately they don't deliver to Turkey. I haven't use mine intensively. I guess it has run less than 200 hours in total.

It does not have a plate. Therefore I can not tell which model it is. It has four stages positioned in + form. Oil pump is behind the propeller. I have mounted it on a metal frame with a 5 hp suzuki engine coupled with a V belt.

Do you have seals of it?

 

[pescador775]

Your post continues to be mysterious. Some Army versions of the 4 stage compressor were trailer mounted and directly coupled to a gas engine and turned in the counter clockwise direction. However, some mods, like those used in the M60 tank, were coupled to an electric motor and turned clockwise. Maybe this is what you have.

When you say the the cylinders are + configured, do they stand at 90 degrees to the crankcase or are the 2nd and 3rd stages canted at 60 degrees? Does the unit have a metal tube running from the crankcase to the first stage? Positive crankcase ventilation is what it is called.

Are you claiming that the seal is responsible for the low air output? Have you checked for bubbles?

Is the first stage black or is it the color of matte chrome (looks like aluminum)?

What does the oil tank look like? Be specific this time, please. I need to know how it is connected and what side of the compressor it is mounted on. Is it bolted to the crankcase or held by a front mounted bracket?

I may have a seal for it but these metal seals can be hand made. Trace the form and cut it. There is an inexpensive cutter called a gasket cutter made for cutting circular shapes. A compass used by architects might work but it needs a sharp blade.

If you have a 890 series compressor such as 890228, etc. I can probably find a seal but I need to know more about this thing.

You must use Mobil JET II oil in the compressor. This is aircraft turbine engine oil, NATO code 156. Other brands of this oil are Aeroshell and Royco. MILITARY specification 23699.

EBOOKS sells the tech manual for the latest model of the 4 stage compressor but not very old mods as far as I can tell.
http://www.tpub-products.com/index....age=2&osCsid=e2e94a2738e27355b40169c0dc4819aa

I can sell you a working compressor, rebuilt, for USD400 + shipping but I don't know how the heck I would get it to Turkey. UPS + a hefty fee? If that is what you want I will try.
Pesky

Pescador, Thanks for your answer. My compressor has four stages. The leakage comes from the seal between the 1st cylinder and man body. It is a metal seal but broken.

I've checked ebay. Unfortunately they don't deliver to Turkey. I haven't use mine intensively. I guess it has run less than 200 hours in total.

It does not have a plate. Therefore I can not tell which model it is. It has four stages positioned in + form. Oil pump is behind the propeller. I have mounted it on a metal frame with a 5 hp suzuki engine coupled with a V belt.

Do you have seals of it?

 

[ekarais]

Pescador, My unit has 4 stages each 90 degrees to as you mentioned. The first stage cylinder is black. I turn it in correct direction since there is an arrow on the propeller.

There are two tubes coming out of the crankcase. First one connected to the oil tank is thicker (should be oil outlet from to crankcase) and is fitted right bottom point of the case. The second tube connected to the oil pump is thinner (should be oil inlet to the crankcase) and is fitted to a higher point on side of the case.

The oil tank dimensions are 50*160*90 mm (w*l*h) approximately. It is located very close to the crankcase (I use the same bolt for fix the tank and the case to the base frame) under the 2nd or 3rd stage.

I can't send you a picture. Because it is in another location now, therefore I tell you everything by heart).

The mentioned seal is located between this black first stage and crankcase. It is metal and is broken. I've tried to make it by hand but didn't have good tools to cut it correctly. I haven't check for bubbles, but the oil starts to wet the unit from that level and splash everywhere over 100 bars. The maximum I can get is 140 bars (I was getting 230 bars in the past)

It is not easy to find the correct oil here. I use Mobil RARUS 424 (ISO32). I'll try to find Mobil Jet II oil.

Finally, if I can not solve the problem the last solution is to buy from you or to send mine to you for maintenance if you agree. The freight cost by DHL is 85 USD (one way, I've just asked). So it's still feasible to send mine to you or to buy yours.

Pescador, thank you for all these details.

Efe Karaismailoglu

 

[pescador775]

Efe, I must know what side the oil tank is fastened. Looking at the fan, is the oil tank on the right or the left? It sounds like a 'right hand' compressor which would make it Army. I can't be sure at this point.

Set that issue aside. I have never heard of the first stage gasket blowing out. My best guess is that you have excessive crankcase pressure which has ruptured the gasket. Blowby pressure is usually the result of a damaged piston and a blocked relief port. Is there a short, thin tube routed from the oil tank to the bottom of the #1 cylinder?

This tube ducts blowby gas from the crankcase (via the oil tank) where it enters the first stage and helps to lubricate the first stage. Because of this system there is never any significant pressure in the crankcase. However, your compressor likely has huge pressure in the crankcase which is not a good sign. Something has to give way, to fail if this is the case. Luckily, the crankcase didn't crack.

Where does this pressure come from? If there is a problem with one of the stages, a bad fouth stage valve for instance, pressure will mount in the first stage and prevent blowby gases from being ducted into the cylinders in the normal way. Normally, this pressure blows off from a relief valve located on the oil tank, not out a broken gasket.

There is a second blowby relief port drilled into the crankshaft. If the drive adapter and spline is not drilled to match the splined crankshaft the second blowby relief port will be blocked. Even so, the blowby relief valve on the tank should take care of the problem.

This continues to be puzzling.

I do not recommend sending, at considerable expense, a compressor with an unknown problem. It's value as a trade in would only be worth the postage expense or less.

I don't know what to do at this point. I can supply a left handed or right handed compressor. However, I do not have any available right hand tanks. This is not a problem. Should you have a right handed tank you can just bolt on the old tank. I would include a relief valve as well in case yours is damaged or missing.

Also, I should mention that I have a new Kidde compressor, left hand tank. This is the latest model and has never been used, zero hours on the clock. I have just one. $600.
However, you would find that the rebuilt compressors are very similar to new in appearance and function.

Keep talking, maybe the answer is in sight.
Dennis, AKA Pesky

 

[ekarais]

I will send you some pictures of my unit within next week. Then we will understand what is it.

It was a bad idea to send you my compressor. I agree with you. Let me try to fix it first. If I can not succeed than I will buy yours.

Talk to you soon. Bye for now.

Efe

 

[pescador775]

Pictures are helpful, thanks.
I checked the specs for Rarus 424. It would appear to be a good choice for this type of compressor. However, Rarus is a mineral oil and not accepted lubricant for the KIdde high speed compressor. These small compressors require synthetic oil. Mobil JET II and Aeroshell 500, are accepted types. Any oil that meets the MIL spec 23699.The Mobil oil is the most widely sold turbine oil in the world. Aircraft suppliers should have this stuff. If not, I could include two liters, no charge, if the shipper has no objections, if it comes to that. No need to tell them, I suppose.
Pesky,

 

[ekarais]

Pictures are helpful, thanks.
I checked the specs for Rarus 424. It would appear to be a good choice for this type of compressor. However, Rarus is a mineral oil and not accepted lubricant for the KIdde high speed compressor. These small compressors require synthetic oil. Mobil JET II and Aeroshell 500, are accepted types. Any oil that meets the MIL spec 23699.The Mobil oil is the most widely sold turbine oil in the world. Aircraft suppliers should have this stuff. If not, I could include two liters, no charge, if the shipper has no objections, if it comes to that. No need to tell them, I suppose.
Pesky,

Hi Pesky,

Here are the pictures of my Kidde finally. What is your opinion?

 

[ekarais]

Hi Pesky,

Here are the pictures of my Kidde finally. What is your opinion?

I've dismantled my compressor unit. I'm adding some more pictures now. 2nd stage valve spring is broken. Another sealing under the 1st stage cylinder cover is weak. There are a couple of o-rings which have to be replaced. The rest seems to be ok! I have also found out its plate. This is a 4CFM 3000 PSI unit turning with 3750 rpm.

What is your idea? Can I find these spares?

Knd regards,

Efe