air compressor pressure drop

Ratae said:

.I'd missed 'you can't use them with an extension'. You can - mine's in the back of the van so all the time - BUT you need a good quality heavy duty one & fully unroll it.
The chap with the 3 hp I mentioned hasn't had any problems with his extension either.

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many thks

well the new toy turned up

it says i’ve got to run it for 10 x minutes and not under load and to open the outlet valve, but they are the quick release valves

daft question plse, do i just plug in the hose and let it run, or do i have to plug something in the end so it’s open to atmosphere, sorry once again for the daft question

checked the oil level and that’s ok, will have to buy some more, then after 10 x hours i’ve got to change i, so will buy 2 x litres , it need to check how much it takes

thks again

Look under the tank. There is a brass plug. Has a knurled bit in the middle which looks a bit like a brake bleed screw & works in the same way. Function is to drain the water that will build up as a result of compressing air. (Referred to in the instruction manual as the 'Drain cock' see Page 13)
Slacken that off so when you do your 10 mins initial run the air just blows out past it. Keep an eye on it so it doesn't disappear in case the vibration causes it to fully unscrew & drop out - if it will fully remove without using force then I'd do that.

Ratae said:

Look under the tank. There is a brass plug. Has a knurled bit in the middle which looks a bit like a brake bleed screw & works in the same way. Function is to drain the water that will build up as a result of compressing air. (Referred to in the instruction manual as the 'Drain cock' see Page 13)
Slacken that off so when you do your 10 mins initial run the air just blows out past it. Keep an eye on it so it doesn't disappear in case the vibration causes it to fully unscrew & drop out - if it will fully remove without using force then I'd do that.

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that’s fantastic and very helpful

just don’t want to mess it up and ensure i done it correctly , think the thing that also confused me at first was the oil level being well below the motor so assumes it had to store a lot of oil

will find a picture of a compressor , so i can then understand it better

most appreciated for the great help , thank u

Don't undo the drain plug all the way out, especially if the tank is full. The pressure is unbelievable. Don't ask me how I know .. What I did in a picture frame factory was run all the lines in 15mm copper with an outlet at every work station . Did plan to do this in my workshop to save having hoses all over the place and getting trapped under wheels .

mick the builder said:

Don't undo the drain plug all the way out, especially if the tank is full. The pressure is unbelievable. Don't ask me how I know .. What I did in a picture frame factory was run all the lines in 15mm copper with an outlet at every work station . Did plan to do this in my workshop to save having hoses all over the place and getting trapped under wheels .

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thks and good to know , copper pipe u say , don’t tempt me as my plumbing / heating days will be useful then ,

still thinking of the best location, am wondering about fitting it under the stairs , maybe making an insulated box made out of mdf for noise / hiding it abit / can cut an air grill into one side of the panels

or maybe just a removabale panel to hide it, making it look like understairs cupboard , then move it to just inside the front door when i wish to use it, or leave it where it is

another idea is outside , by my kitchen door under a lean to, just toying with all different options at the moment, don’t know how it would effect it stored outside , ref water in the tank or damp into the electrics, as the lean to is well protected and bone dry

I do drain the water out of mine when there's air pressure in the tank. Unplugged from the electrics. Helps to blow the water out. But as said above CAREFULLY slacken the bleed screw or it will definitely disappear into the distance. At this time of year you're also likely to find the escaping air will cause the water to freeze round the drain plug.

Ratae said:

I do drain the water out of mine when there's air pressure in the tank. Unplugged from the electrics. Helps to blow the water out. But as said above CAREFULLY slacken the bleed screw or it will definitely disappear into the distance. At this time of year you're also likely to find the escaping air will cause the water to freeze round the drain plug.

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That's what I meant, just enough pressure to blow the water out.

Ratae said:

I do drain the water out of mine when there's air pressure in the tank. Unplugged from the electrics. Helps to blow the water out. But as said above CAREFULLY slacken the bleed screw or it will definitely disappear into the distance. At this time of year you're also likely to find the escaping air will cause the water to freeze round the drain plug.

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thks, that makes sense

remember i had an old box on wheels , so i’ve put the compressor inside it, will be considerably easier to move around

taken the drain 3/8 valve out the bottom of the tank and will get some fittings and lever valve, drill a hole through the bottom of the box , i can then just open the valve to drain the water out

daft question is it ok to use brass fititngs on the tank or stainless steel plse

looked at fititngs , 3/8 nipple , not a running one, then onto a 3/8 lever valve and cap , or hose pipe attachment after the valve

will make a ply or mdf lid , so i can then simply wheel it under the stairs out of the way

wondered what do u think plse ,

When it’s running, it’s all about airflow to cool the compressor

freelance said:

When it’s running, it’s all about airflow to cool the compressor

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thks, when it’s running will remove the lid , then when it cools down will reinstall the lid and wheel it under the stairs

think maybe some air vents in the lid might be a good idea

Swapping to a lever valve on the drain makes life easier & I've been meaning to do it for years but never got round to it - even though I live less than a mile from the compressed air specialist that I bought it from & pop in from time to time when I need airline fittings. Even though it's in the back of the van I usually forget - must be an age thing
I expect the whole plug c/w drain plug bit will unscrew - mine does - but I don't know what the thread is.
Brass will be fine.
Lid off the box when running. As you might have found out the motor & the metal pipes on the compressor get rather hot.

Ratae said:

Swapping to a lever valve on the drain makes life easier & I've been meaning to do it for years but never got round to it - even though I live less than a mile from the compressed air specialist that I bought it from & pop in from time to time when I need airline fittings. Even though it's in the back of the van I usually forget - must be an age thing
I expect the whole plug c/w drain plug bit will unscrew - mine does - but I don't know what the thread is.
Brass will be fine.
Lid off the box when running. As you might have found out the motor & the metal pipes on the compressor get rather hot.

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brilliant , unscrewed the fitting and left with a 3/8 bsp thread

found this stainless steel pipe , so i can then come straight out the bottom of the tank, however i’m not sure about the psi rating plse

https://www.ebay.co.uk/itm/STAINLESS-STEEL-316-PIPE-TUBE-BSPT-1-4-To-2-ASTM-A312-/122925883432

wondering if i would be so kind to have a look plse , can’t find brass anywhere , don’t want to use steel as it will just rust over time


fititngs wise ,

1 x 3/8 straight pipe 100mm long
1 x 3/8 tee
2 x 3/8 short shoulder nipple
2 x 3/8 cap
1 x 3/8 lever valve

will make up a condense tee , useto do it on gas line mains

it’s just the psi rating i’m concerned about plse

many thks and will indeed use it with the lid off, am pleased with the box and will make life easier , just can’t find this short pipe

gstuart said:

that’s fantastic and very helpful

just don’t want to mess it up and ensure i done it correctly , think the thing that also confused me at first was the oil level being well below the motor so assumes it had to store a lot of oil

will find a picture of a compressor , so i can then understand it better

most appreciated for the great help , thank u

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Gary, not sure what you mean by the oil level being lower than the motor etc.
The pump oil level is where it is on the dipstick just like a car sump, there won't be lot of oil there ,it only comes to the bottom of the crank centre line roughly. The piston and crank bearings are lubricated by little steel fingers attached to the crank which dip into the sump oil every revolution and flick it up the bore. The inlet and exhaust valves are controlled by the suck and blow from the piston going up and down, no lube necessary there.
I wouldn't run it in a box unless you mount a fan to blow into it and a vent to allow the hot air to escape.
Just gently nip up the knurled brass drain plug, if you over tighten they can be difficult to undo next time so you end up using pliers or something which stripes the knurling and eventually the whole thing.
Fairly easy fix if that happens though but usually involves cutting the brass thread out of the steel tank to fit an elbow and ballvalve.
Mine are fitted with auto drains but they are pricey but useful if the compressor isn't easy to Access like mine.

Steel fittings will be fine for the tank, use a brass valve to the steel fitting.

Flossie said:

Steel fittings will be fine for the tank, use a brass valve to the steel fitting.

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bless u, just reading through ur previous thread, lol

found this stainless steel pipe which is perfect but i’m unsure about the pressure , always like to ask on the side of caution

in the link below plse ,

https://www.ebay.co.uk/itm/STAINLESS-STEEL-316-PIPE-TUBE-BSPT-1-4-To-2-ASTM-A312-/122925883432

Pressure will be fine but your wasting your money!
I'd get malleable iron fittings in galv.
Stick an MF elbow in the tank, short nipple to that (only to save reaching under to get at the valve) and a ball valve to that. Stick a pushfit fitting in the ballvalve and a length of that nylon air tube into that, then you can aim the drain water somewhere instead of blasting it wherever the valve is pointing, if you see what I mean?

Flossie said:

Gary, not sure what you mean by the oil level being lower than the motor etc.
The pump oil level is where it is on the dipstick just like a car sump, there won't be lot of oil there ,it only comes to the bottom of the crank centre line roughly. The piston and crank bearings are lubricated by little steel fingers attached to the crank which dip into the sump oil every revolution and flick it up the bore. The inlet and exhaust valves are controlled by the suck and blow from the piston going up and down, no lube necessary there.
I wouldn't run it in a box unless you mount a fan to blow into it and a vent to allow the hot air to escape.
Just gently nip up the knurled brass drain plug, if you over tighten they can be difficult to undo next time so you end up using pliers or something which stripes the knurling and eventually the whole thing.
Fairly easy fix if that happens though but usually involves cutting the brass thread out of the steel tank to fit an elbow and ballvalve.
Mine are fitted with auto drains but they are pricey but useful if the compressor isn't easy to Access like mine.

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aplogises , never had one before and after spending the evening reading , feel i’ve got a better understanding

like an upside down engine as the piston goes down towards the air tank, having a reed at the top to control the inlet and exhaust , but thks for more info

it has an oil lever sight glass on the side

i won’t put the lid on whilst using the comp , it’s to save my back and can just wheel it to the front door, leave in the hallway and run it from there , so with the lid off and front door open i will ensure it then gets plenty of air

If you want the ballvalve outside the box you could even stick a pushfit straight to the tank and run the nylon to a ballvalve outside the box if you wanted.

Flossie said:

Pressure will be fine but your wasting your money!
I'd get malleable iron fittings in galv.
Stick an MF elbow in the tank, short nipple to that (only to save reaching under to get at the valve) and a ball valve to that. Stick a pushfit fitting in the ballvalve and a length of that nylon air tube into that, then you can aim the drain water somewhere instead of blasting it wherever the valve is pointing, if you see what I mean?

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^^^This.

Flossie said:

Pressure will be fine but your wasting your money!
I'd get malleable iron fittings in galv.
Stick an MF elbow in the tank, short nipple to that (only to save reaching under to get at the valve) and a ball valve to that. Stick a pushfit fitting in the ballvalve and a length of that nylon air tube into that, then you can aim the drain water somewhere instead of blasting it wherever the valve is pointing, if you see what I mean?

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many thks and indeed follow u, you’ve reminded me as i’ve got some small pushfit fittings left over from my air suspension

good idea with it coming out the side instead of underneath and will indeed save me messaging around trying to get underneath , good thinking

will also be easy to just drill a hole through the side of the box , to keep it nice and simple