Intend buying a new Air Compressor, up to now have used an 8 bar Clarke
model.

Looking at Machine Mart they have loads of compressors, many with
little difference between them ... looking for a 24 litre air receiver
..... Again there is plenty of choice .... But the key thing is Air
Pressure ..... majority are 8 bar models 1.5hp ..... but you can get
10 bar, but they are about 45% more expensive.

I was just about to buy an 8bar 7cfm model on sale as a special at a
big discount, and then chickened out at last moment. (would be more
than double price to get the equivalent 10bar model)

Trying to understand if/why I would need 10 bar, all my air nailers
etc. run at around 6 bar or less.
When do you need 10 bar? .... Assume it can't be for spraying as here
it would be cfm that is important not an extra 2 bar of pressure.

Anybody any idea ?

Rick wrote:
Intend buying a new Air Compressor, up to now have used an 8 bar
Clarke model.

Looking at Machine Mart they have loads of compressors, many with
little difference between them ... looking for a 24 litre air receiver
.... Again there is plenty of choice .... But the key thing is Air
Pressure ..... majority are 8 bar models 1.5hp ..... but you can get
10 bar, but they are about 45% more expensive.

I was just about to buy an 8bar 7cfm model on sale as a special at a
big discount, and then chickened out at last moment. (would be more
than double price to get the equivalent 10bar model)

Trying to understand if/why I would need 10 bar, all my air nailers
etc. run at around 6 bar or less.
When do you need 10 bar? .... Assume it can't be for spraying as here
it would be cfm that is important not an extra 2 bar of pressure.

Anybody any idea ?

How about...when you have two air tools on the go at the same time?
--
Sir Benjamin Middlethwaite

"Rick" wrote in message
oups.com...
Intend buying a new Air Compressor, up to now have used an 8 bar Clarke
model.

Looking at Machine Mart they have loads of compressors, many with
little difference between them ... looking for a 24 litre air receiver
.... Again there is plenty of choice .... But the key thing is Air
Pressure ..... majority are 8 bar models 1.5hp ..... but you can get
10 bar, but they are about 45% more expensive.

I was just about to buy an 8bar 7cfm model on sale as a special at a
big discount, and then chickened out at last moment. (would be more
than double price to get the equivalent 10bar model)

Trying to understand if/why I would need 10 bar, all my air nailers
etc. run at around 6 bar or less.
When do you need 10 bar? .... Assume it can't be for spraying as here
it would be cfm that is important not an extra 2 bar of pressure.

Anybody any idea ?

===================
Sand blasters need the higher capacity and some of the tools like needle
scalers etc. One difference to look for (regardless of size) is 'oil free'
or otherwise.

Cic.

Rick typed:

Intend buying a new Air Compressor, up to now have used an 8 bar
Clarke model.

SNIP

Anybody any idea ?

The most important thing with a compressor is Volume, CFM
Bigger is _always_ better, since most air tools run below 150psi you are
pursuing the wrong spec.


-

"Rick" wrote in message
oups.com...
Intend buying a new Air Compressor, up to now have used an 8 bar
Clarke
model.

Looking at Machine Mart they have loads of compressors, many with
little difference between them ... looking for a 24 litre air
receiver
.... Again there is plenty of choice .... But the key thing is Air
Pressure ..... majority are 8 bar models 1.5hp ..... but you can
get
10 bar, but they are about 45% more expensive.

I was just about to buy an 8bar 7cfm model on sale as a special at a
big discount, and then chickened out at last moment. (would be more
than double price to get the equivalent 10bar model)

Trying to understand if/why I would need 10 bar, all my air nailers
etc. run at around 6 bar or less.
When do you need 10 bar? .... Assume it can't be for spraying as
here
it would be cfm that is important not an extra 2 bar of pressure.

Anybody any idea ?


If your receiver (tank) is pumped to the higher pressure then you have
more energy stored so a given tool will run longer before the
compressor has to start up again. Few tools 'need' more than 100 psi
and run at a regulated lower o/p pressure, but things like sand
blasters are dramatically more effective above 100 psi

AWEM

On 23 Nov 2005 14:50:00 -0800, "Rick"
wrote:

Intend buying a new Air Compressor, up to now have used an 8 bar Clarke
model.

Looking at Machine Mart they have loads of compressors, many with
little difference between them ... looking for a 24 litre air receiver
.... Again there is plenty of choice .... But the key thing is Air
Pressure ..... majority are 8 bar models 1.5hp ..... but you can get
10 bar, but they are about 45% more expensive.

I was just about to buy an 8bar 7cfm model on sale as a special at a
big discount, and then chickened out at last moment. (would be more
than double price to get the equivalent 10bar model)

Trying to understand if/why I would need 10 bar, all my air nailers
etc. run at around 6 bar or less.
When do you need 10 bar? .... Assume it can't be for spraying as here
it would be cfm that is important not an extra 2 bar of pressure.

Anybody any idea ?

I have a 10bar,2.2kW 150 litre compressor for my workshop airline ring
main system (SIP 06646)

http://www.worldofpower.co.uk/acatal...fessional.html

However, I was more concerned about having plentiful air storage and
delivery rate than absolute pressure. The 10bar aspect came with
that.

I use a number of air tools which use a lot of air as well as doing
spraying. I also have a number of medium air use nailers and
similar which, as you say, are happy at around 6 bar, and assorted
things such as tyre inflaters and blow guns. There are then some
pneumatic clamps and similar that I use on my table saw.

The compressor is connected directly to the ring main and then there
are drops to filter/regulator/lubricator units, e.g.

https://secure.thorite.co.uk/Product..._unit_885.html


which give adjustable pressure outlets with and without misted oil
lubrication for nailers etc.

Since the compressor is relatively large, it is hoisted high up out of
the way in the roof space of the workshop. Clearly I don't want to
keep climbing up and down the ladder to change the pressure for
different purposes.

Having the 10bar maximum does mean that the motor runs less frequently
during operation. However, the things to look for in choosing a
compressor are the air production rate and receiver size, considering
the application.

If you are mainly using nailers and the like, the 24litre type that
you mention is more than adequate. It would also do a reasonable
amount of spraying. If you wanted to use heavier air use tools or
do a lot of spraying, then a more substantial compressor would be a
good idea.

These smaller models also have a regulator and you can add a
lubricator if you want it.



--

..andy

On Wed, 23 Nov 2005 23:29:05 +0000, Andy Hall
wrote:


Since the compressor is relatively large, it is hoisted high up out of
the way in the roof space of the workshop.

How do you manage the condensate water drain from the tank with this
installation (roof space mounting of a compressor is an option I'm
looking at for a friends workshop)?

--
Peter Parry.
http://www.wpp.ltd.uk/

On Wed, 23 Nov 2005 23:43:43 +0000, Peter Parry
wrote:

On Wed, 23 Nov 2005 23:29:05 +0000, Andy Hall
wrote:


Since the compressor is relatively large, it is hoisted high up out of
the way in the roof space of the workshop.

How do you manage the condensate water drain from the tank with this
installation (roof space mounting of a compressor is an option I'm
looking at for a friends workshop)?

I used an automatic electronic condensate drain made by Domnick Hunter
- RS carry a similar one - stock code 386-3422. I was fortunate to
get a very good deal on one when I was buying a whole load of stuff
for the project - normally they are about £100, but I paid around £40,
which I thought reasonable for the convenience.

The principle of these is that they fit under the compressor receiver
and condensate trickles down into a reservoir with a float switch
which triggers a solenoid operated valve. There is a breather pipe
which can be implemented in flexible tube that is connected to a tee
into the location where the regulator goes on the top. The whole
chamber remains under pressure. When the chamber fills, the valve
operates for a second or two and compressed air forces the water out
through a second tube. I run that into a large container which I
empty periodically - although it could go straight outside.

An alternative would be to use a mechanical automatic tank drain. Most
of the air equipment manufacturers like Norgren, SMC, Parker etc. make
these e.g. RS stock code 234-1987 Prices around £35 or so. I would
have gone for one of these had it not been for getting the electric
one for a similar price. I have fitted one of these mechanical
drains at each far corner of the airline pipework at a low point - the
pipework is arranged with a slight slope to deal with it.
A bit of air is lost with these, but I don't think that that matters a
lot.


There are various installation options for these devices under
compressor receivers, and the larger compressors have a venting
fitting with a 3/8 thread in the bottom which can be removed.

The main issue was having enough height underneath the compressor to
fit the drain accessory. Some of the larger ones come with wheels
etc. To get around this issue and to improve noise and vibration
(not that this compressor is noisy as its a belt drive running
relatively slowly) I made a mount consisting of two rectangular timber
frames one above the other. I fitted the two together using
Paulstradyn anti-vibration mounts. e.g RS 367-8785
The compressor is bolted to the top frame and the bottom one in my
case just sits on the boarded area in the roof.
For good measure, I fitted eye bolts so that I can hoist the
compressor up into the roof space.

The results are impressive. The compressor runs very quietly and the
drain pops perhaps once a day or so if I'm using air tools for most of
the day. Having the thing out of the way is a significant space
saver as well.







--

..andy

On 23 Nov 2005 14:50:00 -0800, "Rick" wrote:

Trying to understand if/why I would need 10 bar, all my air nailers
etc. run at around 6 bar or less.

10bar is more stored energy in the tank than an 8bar machine, even if
you're still only using it at 6bar. This doesn't make much difference
for continual sandblasting (you'll need real compressor capacity) but it
does allow you to run a "thirsty" tool in short bursts which the
compresor wouldn't otherwise have the volume capacity for.

Cheers for the links.
I already use a triple set up ... water separator, pressure reg &
oiler, and had that connected to my portable compressor (10Lit) tank
using RECTUS type 25 connectors - in fact I use these connectors on all
my air tools as the internal bore is so much larger than standard
schrader fittings. Found that frame nailer & dry wall stapler would
frequently jam on standard fittings (BeA rep advised change to RECTUS)
.... the sudden spurt of volume needed immediately after the drive
action to retract the piston fully)

I want to keep to single phase and 24 Lit receiver for portability, as
this has proved useful in the past ...

I also have a separate 50 litre receiver which I can plug into the
compressor to give me larger volume should I need high volume of air at
any time- but to be honest so far have never found a need for it.

Considering an 8 bar 7 cfm model ... a Clarke Ranger 35 (1.5Hp)
which is reduced to £60 +vat to get a 10bar ver the price hikes to
£130 + vat and up to £150 +vat to get higher cfm of 8.7 (2Hp)

On Wed, 23 Nov 2005 23:22:00 GMT, "Mark" wrote:

Rick typed:

Intend buying a new Air Compressor, up to now have used an 8 bar
Clarke model.

SNIP

Anybody any idea ?

The most important thing with a compressor is Volume, CFM
Bigger is _always_ better, since most air tools run below 150psi you are
pursuing the wrong spec.

While the cfm is important it can (and is) so bodged by the various
manufacturers to make their compressors always look better than they
actually are. For air tool use like a nailer it makes little
difference but this fraud really comes to light when you are using the
compressor semi-continuously (for paint spraying for instance)

On just about *any* new compressor from every discount supplier
costing sub 500 quid take the discharge cfm with a bag of salt. On
anything sub 2000 quid take it with a pinch of salt. Above 2000 quid
they just start to get into trustworthy territory because they usually
quote the free air delivery (FAD) and that is what matters. Also don't
believe the "HP" figures either, they are usually pure story book
fantasy - witness 2HP compressors driven by 1.2kW motors. James Watt
would be turning in his grave.

That 15"cfm" compressor complete with a 150psi, 50 litre tank may
realistically only be able to produce 60psi @ 9cfm continuously.


--

"Rick" wrote in message
oups.com...
Intend buying a new Air Compressor, up to now have used an 8 bar
Clarke
model.
When do you need 10 bar? .... Assume it can't be for spraying as
here
it would be cfm that is important not an extra 2 bar of pressure.

At one time I needed to test out the air equipment of a commercial
vehicle the compressor of which developed around 150 psi (~ 10bar).
The normal line pressure at the operating depot was 10 bar. 8 bar
was just not enough to carry out satisfactory tests.

Next one I get will definitely be 10 bar.

Roger