Compressor rinsing
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And strangely enough our local water is particularly soft and low in other contaminants..... but we knew that before we started using tap water.
I've hot washed the Turmo iv and the Makila; interesting to see that TM are still offering hot wash options on our Arrius [not that we're going to do it] if research shows that this leads to more contamination. Brian, do you know what the calcium content/hardness of the water was in your incident?
I've hot washed the Turmo iv and the Makila; interesting to see that TM are still offering hot wash options on our Arrius [not that we're going to do it] if research shows that this leads to more contamination. Brian, do you know what the calcium content/hardness of the water was in your incident?
Last edited by Droopy; 11th Sep 2005 at 01:23.
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Does anyone have any thoughts on rinsing with filtered water, There seem to be quite a few brands of charcoal filters and the like on the market, would these remove enough of the contaminents to provide satisfactory rinse water???
Our customers fleet had a particular problem. Out of the 4 Arrius 2B1 engines they have, 3 had to be rejected at 1300 hours (tbo 3000 hours) because of compressor erosion. The 4th passed the inspection but has noticeable wear on the compressor.
The reaction has been to bring in a programme of daily rinses (Turbomeca's manual talks about 3 separate processes: rinse, wash and clean), weekly washes and cleaning at 100 hours. The water used is de-ionised which is bought by the box from a local supplier. Each engine requires 3.5 litres per rinse, so that's 42 litres per week for the rinses plus whatever is needed in the weekly wash if you're calculating budgets.
It was also pointed out to the customer that when they've gone to the trouble of buying sand filters, it helps if you leave them switched on throughout the flight i.a.w the FLM. It also helps if you let the engineers fix them when they break, rather than just making it an Acceptable Deferred Defect.
The reaction has been to bring in a programme of daily rinses (Turbomeca's manual talks about 3 separate processes: rinse, wash and clean), weekly washes and cleaning at 100 hours. The water used is de-ionised which is bought by the box from a local supplier. Each engine requires 3.5 litres per rinse, so that's 42 litres per week for the rinses plus whatever is needed in the weekly wash if you're calculating budgets.
It was also pointed out to the customer that when they've gone to the trouble of buying sand filters, it helps if you leave them switched on throughout the flight i.a.w the FLM. It also helps if you let the engineers fix them when they break, rather than just making it an Acceptable Deferred Defect.
trackdirect,
Just seen your message. Charcoal/ other filters will remove contaminants but not minerals like the carbonates found in hard water (from limestone/chalk). You need salt-based water softeners to do that - cause as many problems as they cure.
Just seen your message. Charcoal/ other filters will remove contaminants but not minerals like the carbonates found in hard water (from limestone/chalk). You need salt-based water softeners to do that - cause as many problems as they cure.
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Droopy,
Can only tell you that the water was HARD (bore water). Dont know what treatment it went through, or have an analysis, but was the domestic water used by the oil company in its gas plant, heliport etc. Some people thought it so unpalatable as to not drink the stuff.
blue skies,
Brian
Can only tell you that the water was HARD (bore water). Dont know what treatment it went through, or have an analysis, but was the domestic water used by the oil company in its gas plant, heliport etc. Some people thought it so unpalatable as to not drink the stuff.
blue skies,
Brian
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trackdirect - t & b is correct about the GAC (Granular Activated Carbon) filters, which will only remove chlorine and a few minerals. Similarly, a water softener won't do the job either - they work as ion exchange units, so you'll get other stuff you don't want instead.
There are filter systems (around £500) that will filter water to biological laboratory standards i.e. as pure and electrically resistive as you'll find. If it's good enough for scientific work, I can't believe it'll harm the engines, although we're waiting on the manufacturers to report on minimum quality, as mentioned by Droopy earlier.
t & b - I think you should check the maintenance manual (ref 71-01-01) where you'll find it's 7 litres per engine, administered by two rinses of 3.5 liters, followed by a drying run (with a 5-25 min gap in between each) . . . unless you do a hot rinse when the whole 7 litres goes in at once, albeit at a slower rate!
There are filter systems (around £500) that will filter water to biological laboratory standards i.e. as pure and electrically resistive as you'll find. If it's good enough for scientific work, I can't believe it'll harm the engines, although we're waiting on the manufacturers to report on minimum quality, as mentioned by Droopy earlier.
t & b - I think you should check the maintenance manual (ref 71-01-01) where you'll find it's 7 litres per engine, administered by two rinses of 3.5 liters, followed by a drying run (with a 5-25 min gap in between each) . . . unless you do a hot rinse when the whole 7 litres goes in at once, albeit at a slower rate!
An un-named British subsidary of a large American helicopter company operating out of Warri, Nigeria had a problem with engines on S-76's. Seems they were changing engines faster than they did socks....which knowing some of our engineers would not mean much. Tear down analysis of the engines showed corrosion equivalent to old boat anchors raised from the sea floor after centuries.
Seems the "tap water" was a bit saline....and over a few months was enough to do in brand new engines. I wonder how many engines died an untimely death due to that small oversight?
I would suggest distilled....sparkling clear....pure...pure water for engine washes....any doubt....have your tap water tested before using it. You might be surprised at what you are feeding your engines.
Seems the "tap water" was a bit saline....and over a few months was enough to do in brand new engines. I wonder how many engines died an untimely death due to that small oversight?
I would suggest distilled....sparkling clear....pure...pure water for engine washes....any doubt....have your tap water tested before using it. You might be surprised at what you are feeding your engines.
zorab64
Thanks for that - it's the final day of the weekend here so engineers not on duty (no sleeping overnight on the office floor for them - lucky tykes!). I'll check back with them after my rest day to see if it was me getting hold of the wrong end of the stick (as usual) or a mis-read on their part. Mind you, I did post those figures immediately after chatting with their head honcho, so I might have actually written exactly what they said...
(in other words, blame someone else - ideally the engineers... typical pilot, eh?)
Thanks for that - it's the final day of the weekend here so engineers not on duty (no sleeping overnight on the office floor for them - lucky tykes!). I'll check back with them after my rest day to see if it was me getting hold of the wrong end of the stick (as usual) or a mis-read on their part. Mind you, I did post those figures immediately after chatting with their head honcho, so I might have actually written exactly what they said...
(in other words, blame someone else - ideally the engineers... typical pilot, eh?)
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t&b - thanks. I would concur that a check of stick ends might be useful although, as with may things "TM", it's often a matter of interpretation.
Whilst your post was written after a "chat" with the engineers, I had the maintenance manual in front of me - although there's still plenty to get confused about. . .
If you're trying to determine how to follow the hot wash procedure, for instance, try this; Quote "Apply the washing procedure with the two engines in operation if the wind conditions make necessary to keep the rotor speed to the nominal rating (engine washed: select the GROUND IDLE mode; engine not washed: select the FLIGHT mode, fine full pitch)"
So, does that mean "engine to be washed" OR "engine that has been washed"? Likewise, "engine not yet washed" OR "engine not about to be washed"?
My experience of comp-washing with engines running says that you tend to put the fire out if it's only at Idle but, as with many things translated, there's always room for improvement.
Ho hum.
Whilst your post was written after a "chat" with the engineers, I had the maintenance manual in front of me - although there's still plenty to get confused about. . .
If you're trying to determine how to follow the hot wash procedure, for instance, try this; Quote "Apply the washing procedure with the two engines in operation if the wind conditions make necessary to keep the rotor speed to the nominal rating (engine washed: select the GROUND IDLE mode; engine not washed: select the FLIGHT mode, fine full pitch)"
So, does that mean "engine to be washed" OR "engine that has been washed"? Likewise, "engine not yet washed" OR "engine not about to be washed"?
My experience of comp-washing with engines running says that you tend to put the fire out if it's only at Idle but, as with many things translated, there's always room for improvement.Ho hum.
Hi again zorab64,
We always do the wash with the engine at idle - fire's not gone out yet. Big pain in the butt, as we can't keep the aircon on
(although we leave the sandfilter running). When the wind around the hangars has the usual Kuwait-afternoon gust-spread we do follow the instructions in finest Minglish - ie other engine to Flight while the engine being washed is at Ground, changing-over engines at Flight to minimise the vibration-band risk.
Another area where the 206/7s on the MD902 were far easier to look after than the 135T - comp-wash there is a single-person job during the daily, no fuss no bother.
Haven't heard anything back from Eurocopter about the fact that switching off the Gen to carry out the trend-monitoring in-flight checks involves the sandfilters going off, in direct contradiction to what the Sect 9 says about them remaining on at all times. On a previous type, if the EAPS blowers failed then all the crap that they were sweeping out of the way of the intakes was liable to get ingested in one big lump. Not exactly best practice.
We always do the wash with the engine at idle - fire's not gone out yet. Big pain in the butt, as we can't keep the aircon on
(although we leave the sandfilter running). When the wind around the hangars has the usual Kuwait-afternoon gust-spread we do follow the instructions in finest Minglish - ie other engine to Flight while the engine being washed is at Ground, changing-over engines at Flight to minimise the vibration-band risk.Another area where the 206/7s on the MD902 were far easier to look after than the 135T - comp-wash there is a single-person job during the daily, no fuss no bother.
Haven't heard anything back from Eurocopter about the fact that switching off the Gen to carry out the trend-monitoring in-flight checks involves the sandfilters going off, in direct contradiction to what the Sect 9 says about them remaining on at all times. On a previous type, if the EAPS blowers failed then all the crap that they were sweeping out of the way of the intakes was liable to get ingested in one big lump. Not exactly best practice.
