Cold weather and compressor posts, has anybody else noticed ?

[normspanners]

As per title we have had loads of posts re compressors not starting easily "Oh but it was starting OK a few weeks ago, it has only just started giving a problem" nearly all posts/symptoms could have been written by one person, sorry no------ most have said thank you in some form
HUM coincidence ?? or could it be the weather
Everyone saying it can't be this that or the other
Chaps do yourselves a favour and change your oils first IT DOES NO HARM !!
It is the same with cars some will not start, but there fine after run for a minute,
I wonder why??

 

[SmartWerks]

That's why I preheat the cylinder block in cold weather. It's mentioned I the trouble shooting guide, saying the compressor shouldn't be operated below 5 degrees, i assume that's because of the oil emulsifying as it's not in the right temp range. I'm hoping it will be a thing of the past now I'm fully insulating the shop. A 16amp supply or using a continental plug negates the problem. I've been using a continental plug for a few years now but as I'm getting more serious I've added the suitable power supply as i was needing to run other things which need 16amp supply.

and yes, people who don't thank people for advice their like barristers asking the same question until they get the answer they want.

you would think you could get a winterised oil for the comp? Using motor oil is a big no no apparently from what ive been advised?

 

[brightspark]

dunno how u work that one out dont use motor oil .my compressors over 40 years old and thats all its ever had in it .its a westinghouse the same type are fitted to most diesel engines on wagons and busses air brakes that do literaly thousands of miles and they run off the main engine oil . the only thing i can say that in winter they are harder to turn over when cold . i had a 90cfm v twin broomwade compressor run off a 20hp twin lister engine in summer i could hand crank it over no problem , in winter i couldnt so had to warm the motor and pump up with a blow torch and then it would

 

[the snooper]

there may be 2 problems with the cold weather, one could well be the oil the other is lack of amperage / good power supply which will be amplified by the cold weather, most that post problems are using a 13 amp supply which is adequate while everything is nice and warm and free

 

[normspanners]

i had a 90cfm v twin broomwade compressor run off a 20hp twin lister engine in summer i could hand crank it over no problem , in winter i couldnt so had to warm the motor and pump up with a blow torch and it would

It was my job as the apprentice to start an ex WD 4 wheeled trailer mounted genny with a 6cyl engine, first job in morning, it was fitted with many ways to start it cartridge/clockwork starter(broken)/ electric/ and handle , guess which I had to use ?
Yep handle could start it in summer no problem, winter, I used to have a cut off 45g drum, (barbeque), I would start fire of old broken pallets let it die down and slide it under, for 10 mins worked every time, till I went on holiday and came back to a new genny somebody thought, I actually STARTED the fire under there !! -----with loads of diesel.
I think they got good money for the scrap!

 

[normspanners]

a 13 amp supply which is adequate while everything is nice and warm and free

Wish mine was !

 

[SmartWerks]

dunno how u work that one out dont use motor oil .my compressors over 40 years old and thats all its ever had in it .its a westinghouse the same type are fitted to most diesel engines on wagons and busses air brakes that do literaly thousands of miles and they run off the main engine oil . the only thing i can say that in winter they are harder to turn over when cold . i had a 90cfm v twin broomwade compressor run off a 20hp twin lister engine in summer i could hand crank it over no problem , in winter i couldnt so had to warm the motor and pump up with a blow torch and then it would

I didn't understand why, but there was i legitimate reason that sort of made sense. I'll go find the post so i don't miss quote what i was told.

 

[the snooper]

Wish mine was !

not quite sure what you refer to but you might be able to get medication for it

 

[rtbcomp]

........... Using motor oil is a big no no apparently from what ive been advised?

There's motor oil and motor oil.

AFAIK it's OK to use basic non-detergent single grade engine oil, usually SAE 30 or 40. Apparently detergent oil keeps the muck in suspension and as there's no filter it stays in the oil. On the other hand with non-detergent oil the muck sinks to the bottom and gets flushed out when you change the oil.

 

[brightspark]

I didn't understand why, but there was i legitimate reason that sort of made sense. I'll go find the post so i don't miss quote what i was told.

dont wurry about it they probably are reasons why diffrent oils are specified depending on the make and type

 

[SmartWerks]

There's motor oil and motor oil.

AFAIK it's OK to use basic non-detergent single grade engine oil, usually SAE 30 or 40. Apparently detergent oil keeps the muck in suspension and as there's no filter it stays in the oil. On the other hand with non-detergent oil the muck sinks to the bottom and gets flushed out when you change the oil.

That sounds about right, I was thinking additives - but yes detergent. Thanks buddy, just saved me trying to bloody find the advice someone gave me.

It's being single grade that us causing the winter problems

 

[normspanners]

not quite sure what you refer to but you might be able to get medication for it

I wish my 13 A supply was free

I found this
Name is a bit sus but :-

[paste:font size="6"]Dr. Dmitri Kopeliovich

Compressor oils are fluids used for lubrication of moving metal parts of gas (air) compressors.

The following factors are taken into account in selection of a compressor oil:

• Type of compressor.
• Gas to be compressed.

Chemically active gases (Oxygen, hydrogen chloride) are not compressed in compressors lubricated by hydrocarbon oils (not mineral nor synthetic), which are flammable.
Mineral oils are not used for compressing breathing air.
Hydrocarbon gases (natural gas) may dissolve in the compressor lubricant changing its properties. The lubricant for this application should resist to gas absorption.

• Compressed gas pressure.

Maximum compressed gas pressure is determined by the compressor type.

• Discharge temperature.

Lubricants of low viscosity grades are used in refrigeration compressors and other low temperature applications. High viscosity grade oils are used at increased temperatures. 150°C–200°C For the discharge temperature above 300°F (150°C) synthetic lubricants (polyglycol, diester, polyolester, phosphate ester) are used.

• ISO Designation of compressor lubricants
• Compressors types
• Properties of some compressor oils

[paste:font size="3"]to top

[paste:font size="3"]Corrosion inhibitors, anti-oxidants and anti-wear additives. Higher viscosity indexes are used for higher temperatures. For some applications synthetic lubricants of equivalent viscosity indexes (diester, polyglycol, polyolester or phosphate ester) are recommended. Hydrocarbon lubricant (mineral and synthetic) are never used for compressing active gases (hydrogen chloride, oxygen).

• 
  
  
  • Reciprocating compressor

In a reciprocating compressor a gas is compressed in a cylinder under a moving piston. Intake and release of the gas (air) is controlled by inlet and discharge valves (similar to the internal combustion engine).
There are two lubrication systems in reciprocating compressors: cylinder lubrication and crankcase lubrication.
Cylinder lubrication provides oil to pistons, piston rings, cylinder liners, cylinder packing and valves.
Crankcase system lubricates cross-head guides, main bearings, wristpins, crankpins and cross-head pin bearings.
Both lubrication systems are commonly lubricated by mineral oils from the viscosity range IS VG 68 to ISO VG 220 containing Corrosion inhibitors, anti-oxidants and anti-wear additives. Higher viscosity indexes are used for higher temperatures. For some applications synthetic lubricants of equivalent viscosity indexes (diester, polyglycol, polyolester or phosphate ester) are recommended. Hydrocarbon lubricant (mineral and synthetic) are never used for compressing active gases (hydrogen chloride, oxygen).

• Sliding vane compressor

Sliding van compressor utilizes centrifugal force of a rotating van mounted eccentrically in a cylinder.
Sliding van compressors are commonly flood or injection lubricated. The compressed gas pressure is about 150 psi (1 MPa).
Mineral oils of viscosity grades ISO VG 46, ISO VG 68, ISO VG 100 with anti-wear and mild extreme pressure (EP) additives are used for the sliding vane compressors. Synthetic oils of equivalent viscosity indexes (polyalphaolefin, diester, polyglycol synthetics) are recommended for compressors with increased discharge temperature.

• Centrifugal compressor

Centrifugal compressor uses centrifugal force of an impeller rotating at high speed (up to 20000 RPM).
Bearings of centrifugal compressors are lubricated by oils of viscosity grades ISO VG 32 ISO or VG 46 (for increased ambient temperatures) with anti-wear additives.

• Screw (helical lobe) compressor

Helical lobe screw compressor consists of two rotors mounted in a housing. When the rotors rotate they compress air between helical lobes.
The compressed gas is in contact with the compressor lubricant that may cause its oxidation.
Screw (helical lobe) compressors are commonly flood lubricated either by mineral oils of viscosity grades ISO VG 32, ISO VG 46 or ISO VG 68 with rust and oxidation preventive additives (R&O) or by synthetic based oils of equivalent viscosity indexes (polyalphaolefin, polyolester, diester or polyglycol.
Oil free (dry type) screw compressors utilize timing gear. The gear and the bearings are lubricated an oil from the viscosity range ISO VG 32 to ISO VG 100 (depending on ambient temperature and application).

• Rotary lobe compressor

Rotary lobe compressor consists of two lobes mounted in a housing. When the lobes rotate they compress air between them.
Lobe compressors are lubricated by mineral oils from the viscosity range IS VG 68 to ISO VG 220 with rust and oxidation (R&O) additives and anti-foaming agents. Higher viscosity indexes are used for higher temperatures. For some applications synthetic lubricants of equivalent viscosity indexes are recommended.

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[paste:font size="3"]Materials Data)

• Compressor oil ISO 32
• Compressor oil ISO 46
• Compressor oil ISO 68
• Synthetic compressor oil ISO 32/46
• Synthetic compressor oil ISO 46/68
• Semi-synthetic compressor oil ISO 68
• Semi-synthetic compressor oil ISO 100

 

[the snooper]

I wish my 13 A supply was free

oh right I thought you were having trouble with part of your anatomy

 

[normspanners]

oh right I thought you were having trouble with part of your anatomy

I am --------but that's another post--------
(but not a wooden one)

 

[normspanners]

By far the most common piston compressor is the lubricated single acting air compressor. Oil is present in the crankcase lubricating the crank and rod assemblies. A small amount of the oil passes in to the compression chamber lubricating and assists in sealing of rings and valves. However in heavy load conditions temperatures can become high enough to break down this oil into hydrocarbons that are sticky by nature. Under these conditions valves become coated with this sticky material and catch and hold contaminates that pass through the inlet filters as well as wear materials. This forms a very hard deposit that will cause the valves to stop working properly. Under extreme conditions (compressor loaded more than 80% time) can result in the need to do a valve job in a year or less.

Under these severe load conditions we recommend the use of a diester synthetic such as our PP-7 5 gallon pail for $249.00. These oils resist the formation of the breakdown products plus it removes these deposits. We do not recommended using this product to clean up a compressor as some of the larger deposits may break loose and plug air passages resulting in damage to the compressor and possibly causing a fire from the plugged passage.

Even for compressors under lower loads will result in power saving as valves that leak wastes energy. The use of PP-7 reduces this leakage and will provide for energy savings.

 

[normspanners]

Just another Quote

‘Air Compressors hate cold weather’
Air Compressors and cold weather
Air Compressors are designed to operate in ‘normal’ European ambient temperatures between about 5’C and 35’C. Outside these temperatures they start to have problems with either overheating or freezing. It should be remembered that the ambient temperature should be the temperature around the compressor itself, which is not necessarily the outside air temperature. The compressor ambient temperature will vary from the outside air temperature depending on whether it is in a heated compressor room, in an unheated, ventilated compressor room or outside under a rain cover.

It needs to be stressed that air compressors need to be situated in a very well ventilated place, so even if the room is heated there will still need to be plenty of ventilation for the compressor to work properly.

Problems start when the temperature falls below 5’C
As the ambient temperature starts to fall below about 5’C problems can start to occur. The low temperatures cause several issues within the compressed air system. These are primarily related to the fluids within the compressor itself and to the condensate created in the compression process. Note: when the compressor is running and is up to its normal working temperature the ambient air temperature is not too much of a problem, except if the actual compressed air is routed to a low temperature area and has not been adequately dried.

Air Compressors and cold weather – What can go wrong?
Air Compressor Oil

Oil tends to get thicker The air compressor coolant or oil is affected by low temperatures.when it is cold, if the oil is aged or of poor quality the oil may become too viscous. Either way the thicker oil may prevent the compressor from turning easily enough. This may lead to the electrical system tripping since the electrical demand is too high.

If the compressor is not serviced properly it is possible that the oil will contain a high level of water. This is not a huge problem at normal ambient temperatures but if the temperature falls too far this water can freeze in the oil, causing issues for the compressor at start up or causing damage to the compressor internals.

Air Compressor Condensate
Condensate is probably the cause of the biggest cause of problems for air compressors and cold weather. Condensate is formed when air is compressed and then cooled. Condensate is a mix of water (99%) and oil (1%).

Condensate tends to collect at low points within the compressed air system. These include, the compressor, separators, receivers, filters and dryers as well as in low points in the compressed air pipework. If temperatures fall low enough this condensate will freeze, blocking pipes or voids within the compressor, dryers, filters and pipework.

If there is frozen condensate in the compressor this can cause damage to the compressor, if it is in the filters or dryers again this can cause damage. If there if frozen condensate in the pipework this can get blown to the downstream equipment, again causing damage to the downstream equipment.

Air Compressor Dryers and Filters
Strangely the best protection devices for Air Compressors and cold weather are the dryers and filters built into your compressed air system. This is because this equipment removes water from the compressed air and this prevents water from freezing in the downstream pipework and equipment. So keeping your dryers and filters working effectively is important to protect the rest of your compressed air system.

Refrigerated dryers only work effectively at ambient temperatures above 5’C. So if your dryer is in an unheated compressor room this could be damaging the rest of your compressed air system. Installation of cabinet heating could help protect your dryer and the rest of your compressed air system.



5 tips to protect your Air Compressor in Cold weather
1/ Regularly drain the condensate from your compressor system
You should be doing this regularly as part of your normal daily compressor checks. But in cold weather the condensate can freeze causing blockages or damage within the compressor and compressed air pipework system. As an alternative look at fitting an auto drain system to manage condensate automatically.

2/ Fit cabinet heating inside your compressor cabinet
A simple low power heater fitted inside you compressor cabinet or compressor room will keep the compressor above 5’C and will ensure the compressor will operate correctly even after a long cold weekend.

3/ Use trace heating with appropriate lagging on external pipework
Trace heating and lagging on outside pipe runs will stop any condensate from freezing within the pipes. This will prevent problems of ice being blown into downstream plant. Alternatively look at rerouting pipework inside buildings to keep the pipework above outside temperatures

4/ Make sure your compressor has been serviced regularly
If a compressor is not being serviced regularly a number of issues can arise including a build-up of water in the lubricating oil within the compressor itself. If this water freezes this can cause significant damage to the compressor itself. Also cold oil will be thicker than warm oil, possibly creating overload issues when the compressor is starting up. A cabinet heater will help solve this issue too.

5/ Dont forget your dryers and filters
Strangely your filters and dryers are one of the most important tools to protect your system from cold weather. This makes sense when you consider they remove water from the compressed air so preventing water from freezing downstream in your pipes and other equipment. Refrigerated dryers only work effectively in ambient temperatures down to 5’C. If your refrigerated dryer is in an unheated compressor room the dryer could fail to operate correctly.

The critical issue is to keep the temperature of the compressor above 5’C. This can be achieved by fitting heaters to the compressor itself, or by heating the compressor house. It is also important to heat the filters and dryers. Finally, it is really important to heat the compressed air pipework particularly if it runs outside the building. This is easily done with low power trace heating and suitable lagging.

 

[piman]

Hello all,

aren't we getting a bit overcomplicated, as far as I'm aware most small compressors, i.e the types that run off 13A plugs don't have a lubricating oil circulation system simply a dip and splash feed to the crank. So I don't see how the viscosity of the oil materially affects the load on the drive motor?

Alec

 

[rtbcomp]

^^ the bearings still have to rotate and the piston has to slide in the oil, and if the oil is thick it's harder for these parts to move.

 

[normspanners]

Message to W.I.M.C.---- OK

 

[Turbo]

If you buy one of those chinese import compressors they are usually set up for warmer climates and come with relatively thick oil. I had this problem with a compressor, in cold weather it would not start, even with the drain plug open! My boss at the time advised changing to hydraulic oil, the stuff the huge refridgeration compressors at work used. I filled it with tellus t22, problem solved, it has ran perfect since - not bad considering the compressor was a cheap £50 chinese job.

Since I left that job I had no source for the t22 oil but I found the equivalent at my local motor factors - milking machine oil. (A milking machine pump is basically an air compressor.)

You can get a device that connects to the compressor that bleeds the air output on the pump allowing it to start off load, then once the pump is running it closes and the air goes to the tank.