Liquid ammonia injection for cooling.

[US Iceman]

in re US Iceman, take my word for it there is nothing wrong with the electrical side of the machine unless the installed re-built motor has a spun out rotor and the spare has a spun out rotor in exactly the same manner. While this is a possibility it is highly unlikely. Unless the motor re-wind experts are incompetant, again highly unlikely.

Please be assured I'm not calling anyone incompetent, or in any way pointing fingers. I've seen brand new compressor packages (w/new motors and starters) exhibit similar problems.

I may be reading more into the situation than warranted, but my only point is, there are a lot of things to review (as evidenced by Josips commment on the motor check-off sheet).

[mrsparky]

US Iceman, I am very competent in electrical and checked out the electrical side some time back with direction from a electrical engineering forum. I picked through it like looking for a needle in a haystack. I disassembled the hay stack straw by straw and did not find a needle. That is how closely I checked it. There are non-invasive ways to check for a spun out rotor without disassembling the motor. These are pretty complicated and may be beyond my capability. I did not pursue this test because both motors gave the same symptom of a loud motor noise during start. My gut feeling was that the motor load i.e. compressor had a higher than designed inertial load during start, albiet this could be caused by a partially spun out rotor. While a motor running at 3550RPM is more more prone to rotor spin outs than one running at 1760RPM, this spin out is usually caused by frequent starts and stops. Our compressors are run for months at a time and off for months at a time while their work duty is rotated. Thanks, Robert

[karelsdr]

The timing in wye delta starters varies from site to site(load,voltage,coupling etc.)But 6 seconds sounds like a long time to me.

[mrsparky]

in re karelsdr, your last post sounded like a question.

Star/Delta is old school. Some call it Wye/Delta but it is the same thing. The idea is that at transition to Delta is that you want the least amount of slip between the rotor field and the stator field. The less amount of slip the lower the current at transition. The refrigeration star/delta starters where I work at are designed to cross over at one half of motor RPM. With smaller motors, configured in Star/Delta the inertial load is less and this can be accomplished at a shorter transition time. In my case any reduction of transition time would result in a large over current that trips the 1200A circuit breaker. Extending the time further does not do any good because at 6 seconds the motor configured in Star is turning about as fast as it can and lengthing it only stresses the motor thus the shift to Delta at max Star RPM. Hope this helps. Robert

[Andy]

Hi Mr sparky

what about the transition between star and delta, is there possibly a tranistion spike. This happens if the phase sequence is wrong and you are skipping a set of coils in the motor and spinning it another 90 deg before going to delta, causing a addtional peak of amps called a transition spike.

Kind Regards Andy

[mrsparky]

Hi Andy, We have closed transition starters so the so the phasing problem at transition is not a problem like open transition, if this is what you are talking about. I am positive that that there is absolutly nothing wrong with the electrical side unless both motors are have partially spun out rotors. I would bet my house on it. Replacing the injection valve really improved my machine start. The failure of this injection valve when the machine was stopped was odd in that once in a while it would be OK. Sometimes it would only have frost at the window, sometimes it would only be cold at the window and sometimes it would be so bad that the compressor would be frosting up. This problem was resolved in my original post and the first reply which was yours. Thanks, Robert

[mrsparky]

I have re-read this thread again and hope that I did not sound condensending from any of my remarks. It was not meant that way.

One thing intrigues me about an earlier post from NH3LVR. He mentions a time that he had a problem with a suction valve that caused similar symptoms. He specifically mentions about the bypass being too far open and that to me inplies that it should be open a little bit. Our refrigeration mechanic informed me that our bypass valve is kept closed all the time unless there is a pump down (think that was his words). From reading this thread I asked if the suction valve has a internal bypass. He said that it did not, that it was a older style.

He is my friend and a respected refrigeration mechanic and I am not checking his work so I know we are doing it right. The thing in the back of my mind is like US Iceman mentioned in a earlier post. The injectior valve replacement only masked the real problem and I think he is right. The motor now starts a lot easier than it used to but it still does not sound like the others during start. Like its inertial load is greater than all the others.

[nh3wizard]

I didnt read the whole thread, but is it possiable for the discharge check be stuck open? Maybe causing the hard start?

Just throwing it out there

[Andy]

Hi Andy, We have closed transition starters so the so the phasing problem at transition is not a problem like open transition, if this is what you are talking about. I am positive that that there is absolutly nothing wrong with the electrical side unless both motors are have partially spun out rotors. I would bet my house on it. Replacing the injection valve really improved my machine start. The failure of this injection valve when the machine was stopped was odd in that once in a while it would be OK. Sometimes it would only have frost at the window, sometimes it would only be cold at the window and sometimes it would be so bad that the compressor would be frosting up. This problem was resolved in my original post and the first reply which was yours. Thanks, Robert

Robert

I have never come accross closed transition starters, what way does this work, can you post a link please.

Kind Regards Andy

[US Iceman]

Our refrigeration mechanic informed me that our bypass valve is kept closed all the time unless there is a pump down...

If this bypass valve is the one that bypasses the suction check valve, it is not a bypass valve, but rather an equalizing line (which happens to have a valve in it).

This valve is normally opened just a little bit to equalize the discharge pressure down to suction pressure BETWEEN THE TWO CHECK VALVES (SUCTION AND DISCHARGE).

When the compressor motor is de-energized , the suction check valve closes to prevent excessive backspin on the rotors. Once the rotors have come to a complete stop, the gas pressure is equalized down to suction through this valve.

If the valve is closed, the pressure cannot equalize. This means the compressor would be starting against discharge pressure, which would be the same as what nh3wizard was hinting at.

The purpose of this equalizing valve is to allow the compressor to start at low pressure, and could also be adding to the problems experienced.

[US Iceman]

Andy,

Have a look at this link.
http://www.mastercontrols.com/EngInf...l/TA_RWood.htm

The problem you mentioned is due to the use of an open transition starter. The closed transition style uses a third contactor to keep the circuit energized.

All of the wye-delta starters used for screw compressors here in the US are the closed transition style (at least every one I have seen).

[Andy]

Andy,

Have a look at this link.
http://www.mastercontrols.com/EngInf...l/TA_RWood.htm

The problem you mentioned is due to the use of an open transition starter. The closed transition style uses a third contactor to keep the circuit energized.

All of the wye-delta starters used for screw compressors here in the US are the closed transition style (at least every one I have seen).

Hi Iceman

thanks for the link

yes I can remember seeing this on some older plant, the extra contactor is linked to a set of resistors to keep the magnetic fields going at Y Delta change over.

To be honest I haven't seen this in years. We have two 415volt 355kW motors starting on LV, but they are soft start, quite a lot of 200kW motors starting on open transition Y Delta without any problems I think we have a 250kW on the star delta start, but that is as big as it goes. After that 3300 volts and even one at 11kv on a double tapped trasformer for a two speed start (now that is scary)

I wonder why we don't use the closed transition over this side of the pond now a days, is it our voltage
I was taught to look for transition spikes when commissioning, and would change the leads on the motors to minimise this (means changing four leads), this worked OK for me. Does anyone else do this

Kind Regards Andy

[NH3LVR]

This means the compressor would be starting against discharge pressure, which would be the same as what nh3wizard was hinting at.

The purpose of this equalizing valve is to allow the compressor to start at low pressure, and could also be adding to the problems experienced.

This has not been a problem in my experience. I will concede that most Screw Compressors I work on these days have Soft Starts. Starting problems have not been a major issue for me.
When the Screw is started the pressure is equal on both sides. It is unloaded and I do not think it pumps much in the few seconds it takes to come up to speed.
I do have two machines that use Wye Start/Delta Run. Up to this point I have not noticed any starting difference between full Head Pressure starts and pumped out. Others may have had different experiences. Some machines start differently than others for many reasons.
I do work on machines occasionally without the Suction Bypass Valve. The largest problem I have experienced is that under some conditions they will fill with liquid. It does not take much of a leak when in a Discharge Check or Liquid Injection Valve over a long down period for this to occur.

[mrsparky]

Hi All, Andy, with a closed transition starter the motor is never disconnected from the line during start therefore there are no phasing problems at transition. If you ask me it is a ramshackle design fraught with electrical problems. The contactor connected to the resistors is only pulled in for app. one half of a second at the moment of transition. Timing is crutial and any mishap causes large over currents. I will now be using soft starters when ever we have a closed transition starter blow apart.

I have wondered about the discharge check valve in the past. It was explained to me that when the slide valve is at minimum the gas ony circulates inside the compressor. Please correct me if I am wrong. Something about this last statement seems wrong to me because I have read that the compressor is a positive displacement pump. I have wondered in the past and now if the slide valve is truly at minimum when the dial indicator points to zero. Then again this would not make a difference if it is off much since the gas that is not being discharged is only circulating. Please remember that I am in new territory here but have a good physics understanding.

[TXiceman]

First you need to be sure the slide valve is properly calibrated and the compressor will not start unless the slide valve is at minimum position.

Next, is this a high stage compressor or is it a booster compressor? If it is a booster and a smaller motor, it could have problems using a wye-delta starter.

Also, has anyone made a check on the motor starting torque to see if it can start the compressor in wye windings?

Until you can get the liquid solenoid repaired, if the machine will be shut off, manually close the block valve to the liquid injection and tag the unit out of service. As long as it is running the solenoid is open and the leak is not a problem.

What is the separator temperature prior to starting?

Ken

[mrsparky]

The oil temperature in the separater tank was 109 degrees F at start.

This is a high stage compressor. Our high stage compressor motors are 500HP and the booster motors are 400HP.

The motor starts the compressor in wye but the RPM was app. 20% lower than a working compressor at transition when I made the measurement some months back. This machine does not have the high pitched whine during start that the other compressors have.

The liquid injection solenoid was replaced and this helped out during start (less noise).

I do not know how to measure motor torque during start. I am a electrican and not an electrical engineer. If I could make this measurement with an uncoupled motor during start this would tell me if the rotor has problems. If the problem is electrical it would have to be a partially spun out rotor and the spare would have an identical problem. This is a possibility because both motors are old and rebuilt except for the rotor. I have been over the electrical with a fine toothed comb except for the rotor. There is a test that energizes the motor winding with a reduced voltage. Then as you rotate the motor, current measurements are taken to check the condition of the rotor. I think that the currents should remain stable. I may read up on this better and try this approach also.

[TXiceman]

mrsparky, to check the motor torque, you will need to get the speed-torque data and the starting torque of the compressor from the manufacturer. It should be in the data in the technical manual. Now you need the speed-torque data from the motor manufacturer to overlay with the compressor data. The motor manufacturer should be able to help with this for you.

The compressor curve should be below the motor curve for motor to pull the compressor up on start. With a Wye-delta starter, you need to be sure you have the torque to get the compressor rolling and accelerate while in the wye configuration.

While the soft start starters are gaining in popularity, the wye-delta is still a viable method of starting a motor to limit inrush.

You stated that you are in wye windings for about 6 seconds. Is the motor still accelerating at this point or has it peaked out. Have you tried to shorten the time for transition? I ahve seen a number of applications where they performed better by shortening the time for transition. The motor vendor should be able to help you with the time.

Ken

[US Iceman]

When the Screw is started the pressure is equal on both sides. It is unloaded and I do not think it pumps much in the few seconds it takes to come up to speed.

With screw compressors, unloaded and slide valve position are two different animals. The slide valve can be at 0%, but the compressor still has some pumping capacity. After reaching full speed (at 0% slide valve position) the compressor typically has somehwere between 10% and 20% of the full load displacement trying to pump.

The critical thing in this thread is not the problem after reaching full speed, it's the problem of reaching full speed.

Once the rotors reach about 50% speed they start to pump more gas. This is also somewhere around the RPM where the starter (in question) begins to have problems.

This is the reason why the slide valve has to be at 0% slide valve position and the pressures are equalized in the compressor. Anything that can cause the toque load to be higher during start can affect the starting ability.

On full voltage starters you hardly if ever see these problems. On wye-delta start and auto-transformer it's a different problem and the speed torque curves are essential in determining what the problem is, or is not.

If the compressor requires more torque than the motor can develop during this time, strange noises and things happen.

When TXiceman comes back, maybe he can confirm (or deny) these points, but I believe this is true.

[NH3LVR]

When TXiceman comes back, maybe he can confirm (or deny) these points, but I believe this is true.

I never doubt you Iceman!
I am due to do some service on a Wye Start/Delta Run 400HP Screw this spring. I have been after them to install a 1/4" bypass but it will require some welding, so it has not been done. I bleed the machine off with a hose before I work on it. Perhaps I will take some Amperage readings just to compare.

[US Iceman]

I have been after them to install a 1/4" bypass but it will require some welding, so it has not been done.

That must be one of the older packages as I was under the impression almost all of the newer ones had the equalizing line around the suction check.

Unless... it is one of those that have a small hole drilled in the check valve plate(s) for equalizing the pressures.

[NH3LVR]

It is an old Mccormack Screw. We replaced the panels with FES. Unfortunately there is no hole through the check valve. Still run good though.

[US Iceman]

Well... at least I was half right.

[mrsparky]

Tonight I will try and perfrom the "Single Phase Test" to check the motor rotor. If I can get the right voltage, 10% of line, for the test, and it passes then I will be focusing on the slide valve.

How do I prove that the slide valve is at minimum when the dial indicator points to zero without disassembling the compressor or using x-ray.

This motor sounds like it has trouble from the git go. The high picthed whine is absent (heard on all the other compressors) and sounds to be struggling close to the beginning of start and before it reaches one half motor plate RPM which should also be the transition point. As compared to working machines. This machine can not reach one half motor data plate RPM even if you left it in wye for as long as you wanted. Of course even in a working machine the motor cannot speed up much over one half data plate RPM before it ceases to accelerate while in wye after you have extended the transition time. The fault sounds like it is occuring only in wye. Once delta is connected you can hear that the motor has enough torque to wind out.

I of course have checked electrical connections all the way back to the main switch gear. The motor does not have a current imbalance any different from a working machine. The voltage is less than 1% imbalance.

I can manually operate the slide valve at the control station. If I load up the machine to 100% by the digital readout at the control station, the mechanical dial indicator is pointing to 100% and motor current is at FLA. If I manually unload the machine from the control station to 0% then the dial indicator is pointing to zero and the motor current is app. one half of FLA and this measurement is in agreement with a working machine by less than a factor of 10%. I can supply more accurate data when I get into work tonight. This seems to steer me away from the slide valve. Is my thinking correct?

[US Iceman]

The voltage is less than 1% imbalance.

That's not bad, but it can affect the torque output of the motor slightly. If the motor torque available is marginal, then any other factor affecting it adds to the starting problem.

Since you have ruled out the electrical side of things, I think you need to ask FES and the motor manufacturer for their speed torque curves and verify the combination is correct.

If I load up the machine to 100% by the digital readout at the control station, the mechanical dial indicator is pointing to 100% and motor current is at FLA. If I manually unload the machine from the control station to 0% then the dial indicator is pointing to zero and the motor current is app. one half of FLA...

Which is exactly why you do not want to see screw compressors operating in an unloaded state. They use a lot of energy very inefficiently in this condition. just a tip to look for this if you are trying to save energy.

[TXiceman]

US Iceman was correct. The Compressor starts with pressure equalized across it at minimum slide valve position.

Which compressor is on the package, is it a D/B, Mycom, Howden, Kobe or a GEA. FES has used them all. All of these use hydraulic pressure to load and unload. It is simple enough to manually drive the slide valve to minimum position and check calibration to show minimum position on the control panel dispaly.

As the machine starts, watch the manual slide valve indicator to see it it tries to load.

I am beginning to think that the motor may not have enough torque in the wye configuration to get the compressor up to speed. Either due to not enough motor torque or too much compressor load.

Is this a conventional design with the compressor mounted on top of the separator or is the compressor mounted on a frame with a vertical separator on the end. In this case, the compressor is "submerged" and can have problems starting if you run the oil pump an excessive amount of time prior to starting. The compressor is logged with oil and the motor has to push the oil out of the casing while starting. You can also get this if the machine does not go to minimum load at shut down.

I like to manually unload the compressor to miminum load and then shut it down with a submerged design.

As I had noted earlier, 6 seconds may be too long in wye windings. Try to shorten the time to transition to 4 seconds or maybe even 2 seconds.

As a last resort, you may need to install a bypass around the compressor to keep the pressure down and time it out once started and close the bypass. The bypass will have to be pretty large to move the gas and keep the discharge pressure from building.

Excuse my rambling, but I tend to solve problems by talking out loud and see what if anything makes sense. I try not to answer myself too often when other people are watching.

If you can provide the compressor model, I maybe able to come up with the speed torque data you need. You will have to contact the motor vendor for the data in the wye and delta configurations.

Ken

[mrsparky]

Sorry I took a little time to get back to the forum. I am preparing to do the single phase test with guidance from an electrical engineering forum. If the motor passes the test then I will be almost positive that the electrical side is not causing the problem

The compressor is a conventional package with the motor and compressor mounted on top of the tank. The compressor is a "Hartford" model number 2512DLR3VDFOEM0010. The motor is 500HP/3550RPM. We have nine compressors here and one other is exactly the same as this one. It does not have any problems so I do not see a need to verify that the motor and compressor are compatable, you may know a reason that eludes me.

That is why I think that this is a real fault and not a design problem.

[US Iceman]

As a last resort, you may need to install a bypass around the compressor to keep the pressure down and time it out once started and close the bypass. The bypass will have to be pretty large to move the gas and keep the discharge pressure from building.

Yep, I've seen this done before on some large screw boosters with wye-delta starters and the "submerged" compressor installation you mentioned. That site had experienced a similar problem to what we are discussing here.

Excuse my rambling, but I tend to solve problems by talking out loud and see what if anything makes sense. I try not to answer myself too often when other people are watching.

I've found this to be a good tool for analyzing problems too, but people do tend to look at you funny when you start to answer yourself.

[US Iceman]

I looked up a model 2512DLR3VDFOEM0010 on the Hartford compressor website. The minimum torque values are:

Breakaway torque: 130 ft-lbs
Starting torque: 182 ft-lbs

The motor would have to provide at least 182 ft-lbs in the wye configuration to get the rotors up to speed.

We have nine compressors here and one other is exactly the same as this one. It does not have any problems so I do not see a need to verify that the motor and compressor are compatable...

Having others of the same compressor does not mean anything. If the motor on the package in question has ever been changed from it's original, or any other changes made to suction pressure, etc. anything can happen.

From earlier information it appeared this problem had been occuring for several years, so something has been going on here for a long time. It was also mentioned the motor had been in the repair shop several times (maybe less, I don't recall now). What necessitated the motor rebuild(s)?

It's beginning to sound as if you do not want to check the information provided....

[mrsparky]

Quite the contrary, I want to get to the bottom of this. Whatever the solution is, it will seem obvious after all that we have been through.

I am assuming that this compressor is designed to be powered by a 500HP refrigeration motor. The spare motors we have here have been swapped around with different compressors without any problems. If there is nothing wrong with the motor or compressor itself then I should look at external ancillary equipment, i.e. discharge valve, bypass etc.

There is bypass tubing with shut off valve around the suction check valve. This is kept shut off and the suction check valve does not have an internal bleed. I told the refrigeration man that this should be cracked open to equalize pressure when turned off. He told me that FES does not do it that way. From reading other posts this may not make any difference anyway.

We have had motors burn up due to starters blowing up, bad bearings and swelled rotors. We are closely monitoring motor bearings now to prevent this easily preventable fault. When a closed transition starter blows up most of the time the fault cause was never determined (but is most likely caused by welded contacts that can't release when they should) and after replacing contactor contacts, fuses, resistors, etc. it works for years. That is why I sought permission to change the last starter blow up to a soft starter. That project is almost completed and I am only waiting for stud blocks.

I hope this facility does not sound like a hopeless case but I am condensing 8 years of my observation so please don't think we are incompetent.

I am at the point of pulling my hair out on this one, what little hair I have left.

[mrsparky]

I performed the single phase test on the motor to check condition of the rotor. It passed with flying colors. I can now focus on the compressor side.

[nh3wizard]

mrsparky, what part of Georgia are you located?

What kind of liquid levels do you have, and how far from the recirc is the compressor? I have seen where the level has caused hard starting due to the liquid feed not close all of the way and raising the level higher than normal but not high enough to cause a high level shut down, and getting some wet back in the suction on the compressor, plus making it sound differnt on starts.

Just more to throw out there

[US Iceman]

...raising the level higher than normal but not high enough to cause a high level shut down, and getting some wet back in the suction on the compressor, plus making it sound differnt on starts.

Sounds reasonable. That's essentially a flooding problem on start-up caused by the liquid foaming in the vessel.

A quick way to check if this is the culprit is to monitor the discharge temperature. If the discharge temperature goes down during start-up, the problem is due to liquid ammonia.

The discharge temperature should slowly increase to it's normal temperature as the compressor package warms up.

[nh3wizard]

It didnt take long to figure out due to liquid causing the oil filters to plug up.

[US Iceman]

It didnt take long to figure out due to liquid causing the oil filters to plug up.

Did you cut any of the filters apart? The ones I have seen are filled full with a lot of junk that came out of the system.

It's like the liquid flushes all of the debris right of the pipes and vessels and deposit it in the compressor where the oil filters are then left to try to filter the enormous amount of junk out of the oil.

I have ran into this on large system start-ups also. Not much fun...

[Andy]

Hi Mrsparky

most slides have an end stop. 0% is not 0 capacity, usually a machined ring is fitted to the slide piston cylinder limiting how low the slide goes. Time to pull down the screw I think
Check the slide stop and check with Harford what should be in there.

Also do a bearing movement/play check as per manufacturers requirements and check your rotor outlet clearance.

I suppose you could check the VI against your other compressor, probably 3 in this case by the code you quoted and check with the manufacture what the VI should be.

Wish you luck

Kind Regards Andy

[TXiceman]

VI should have minimal effect at start up. Also, has this compressor had this particular motor on it since start up or just since you noticed the starting problem. If you have had the motor rewound, it is possible the motor shop altered the windings enough to have less torque during start up. Do you have another motor to swap out and try on the compressor?

How many hours are on the machine and does it roll freely (with sleeve bearings, it will not roll as freely as a rolling element machine) when disconnected from the motor? Are the rotors meshing smoothly or do they drag.

Have you checked for phase imbalance when under starting load? It may check OK at rest or once running, but one leg may drop while under load.

Does the motor start OK in delta winding? Set your transition time down to 1 or 2 seconds and see how it starts.

A normal torque motor, 500 HP motor should have enough torque to start a 2512 compressor.

I can see that being of the electrical nature, your inclination will be to check electrical and blame mechanical for any problems that may not be explained. The electrical problems are easier to check than tearing into a compressor, so let's exhaust all of the electrical items before we start opening up a compressor that may not need to be opened.

The 2512 compressor has replacable angular contact ball bearings for thrust, but the sleeve journal bearings are pressed in and line bored in place when needing replacement. If you get this far into the machine, you will need a good machine shop to go on from this point.

Oh and Andy, If you can not fix it, remove all traces of evidence that you tried to fix it.

Ken

[US Iceman]

I have a question...

On the oil pre-lube operation before the compressor starts; how long does it take to develop sufficient oil pressure to prove out the safety circuit before the starter engages?

The longer it takes to develop oil pressure with a pre-lube pump, the more time you might have of pumping oil into the compressor, which could also create additional torque loads that have to be overcome.

[mrsparky]

nh3wizard, I work in "Hotlanta" and reside in Forest Park although I have to admit that I am a yankee from the Buckeye State. I am an electricain with limited knowledge about refrigeration but the hi temp recirculator tank is only ten feet away from this compressor. There are two windows on the oil separter tank. The bottom widow is full and the upper window is empty.

I did not work on it any last night but will check the discharge temperature at my next opportunity, if there is a temperature sensor. I am still familiarizing myself with the mysteries of ammonia refrigeration. Once I get through all of this I may try and get certified. Lots of jobs for this trade.

If I set the transition time too low then at transition there is too much slip and the circuit breaker trips.

When I performed the single phase test I had to remove the coupling guard to slowly rotate the motor. The motor was still connected to the compressor and it hand rotates with a force (guess only) of five pounds. It turned relatively easy by hand contrary to what I stated in a much earlier post.

Being the only third shift electrician at the facility, I am called for everything and anything. I derive some pleasure of chastising mechanics when it is a mechanical problem. This problem seems mechanical to me but I can't prove what the cause is yet except that it is not electrical from the motor back to the mains disconnect.

The oil pumps for app. ten seconds before the motor receives a start command.

[mrsparky]

Thanks to all for the moral support and technical support. This project has been put on the back burner for a little while. During the cold months we don't need as many high stage compressors running and other projects are taking precident. I am at an age where I have to forget something in order to learn something new and I have been learning a lot of new stuff lately. I'll resume contact when we start working on this problem again. Thanks again to all. Robert

[mrsparky]

One more tidbit, A manager, a friend of mine, asked me this morning about a propane refrigerator in a camper. I told him that it is an absorbtion machine and told him to rent the Harrison Ford movie "Mosquito Coast". Has anyone every watched this movie and is this technique in the jungle possible? Only watch the first three quarters of the movie and then turn it off.

[Andy]

Oh and Andy, If you can not fix it, remove all traces of evidence that you tried to fix it.

Ken

I feel your pain

Kind Regards Andy

[wolfie]

Is there A bursting disc fitted in the manafold system
My be wrong without more info