Hello, today's Introduction to Manufacturing class is on pneumatics. If you remember from yesterday or the previous session I should say not necessarily
yesterday that the we did discuss hydraulics very similar concepts
hydraulics uses a type of fluid. Pneumatic creates are utilizes the use
of air. So we're going to jump right into some pneumatic terms, psi is used to identify
how much pressure a pneumatic system, 50 psi to 100 psi, psi is equal to pounds per square
inch, that is you know we're gonna talk more about compressed air, which uses an air
compressor. Atmospheric air is the weight per square inch exerted on the earth's
surface by the air from the surface. So if we were at sea level, which would be
nice to be at the beach right about now, if we were the pressure from the
atmosphere that we would actually feel on our shoulders is 14.7 psi so
depending on where you're at
on the planet, if you are on a more higher elevations probably be a little bit less,
if you're below sea level will be a little bit more. So than the matter of
knowing where you're at
really makes a difference. Compressed air that is taking actual atmospheric
air and compressing it or increasing the pressure using an air compressor.
Air compressor converts atmospheric air 14.7 psi sea level to a compressed air,
which is typically above atmospheric air usually somewhere in the neightborhood of about 225 to 250 psi
depending on the type of work you are doing even larger and in some cases. You
want to make sure that you don't over run what your system is capable of handling, so
if you have hoses or tools or you know valves are all rated for a 100 psi to 125 psi
system, you don't want to be pumping
250 psi into that. So keep that in mind a dryer, a drier is used remove liquid from
compressed air
well as you know atmospheric pressure there's usually a little bit of humidity and as you
compress that it creates what, it creates a little bit of heat and it creates a
little bit of water, so you want to be able to remove that you don't want water flowing
throughout your pneumatic system they tend to rust and corrode your parts so you
want to try to dry it as much as possible.
Receiver tank as you know most air compressors usually have a receiver
tank that go along with it, that's part of its part of it's unit. Sometimes you may have
a receiver tank somewhere near your actuator near your valves or
whatever is going to do the work so keep in mind your receiver tank doesn't
necessarily have to be right there.
The term port, I know we're sitting thinking about atmosphere
pressure and being at the beach, you think well there's a port over there, there's probably a
cruise ship on it I can go and get on it, well that's not the type of port. As we learned and hydraulics, a port
is actually a connection point where the hard piping or tubing connects to a
valve or even your air compressor or maybe to your receiver tank or to
something that's actually the location of where things are connected is called a
port. Flow control valves, flow control valves are used to control the speed
actually controls how fast the air is flowing through a device and you can
adjust as usually the flow control valves have adjustments on it.
Pressure gauges are used to provide a reading of the pressure system certain
areas usually they are called psig, pounds per square inch gauge, they either can be
analog using a dial or sometimes most cases now along the digital ones. Digital's
provide a much faster reading and sometimes can even be wirelessly fed to a handheld
device or computer system that's doing the numeric controls for it. Continuing on with
terms, directional control valve can be used to control the flow of the direction
of the compressed air, I like the term detented, these can be detented where the valve
locks and position must be pushed back by a solenoid or spring
operated. So understand that directional control valves are or have to
be controlled somehow either manually controlled or maybe detented or
they can actually be pushed back and forth using certain types of electronic
equipment or like magnets and such, so keep that in mind.
Exhaust muffler may be used for noise reduction when the air motors or exhaust
ports directional control valves are in operation
you will see that when the air is being released from an actuator the air has to
go somewhere and typically that air makes noise and sometimes in large psi systems
that noise can be very large and remember we're working around that,
humans are working around and it can be very loud to our ears and sensitive, so you
can call an exhaust muffler if this is the case for pneumatic system is probably
as a person protecting device to actually protect your ears or the
environment around it. The attached video for a pneumatics, we have a very
good example of a directional control valve, as well as a flow control valve,
there was even a muffler on that you'll be able to see. As long as, as well as a cylinder and
an actuator of a cylinder going up and down, you'll be able to see that and and the
video that's included with this. Continuing on, you have a lockout valve,
it's a pressure blocking valve that relieved downstream air pressure.
What it does is when you lock that out it relieves the pressure at the same time
and what's downstream so if you're working on it, if you're a maintenance person, you need to work on the
line you can turn off a lockout valve, it relieves the pressure, til you see zero on your
reading and then you go over and open it up and work on it all you want to. Shut off
valve is a manual valve used to shut off a pneumatic system. The term proportional
is used to describe the type of an automatic valve, there are different types of
automatic valves proportional is one of them.
Lubricator is used to add lubricating oil at the point of use. So remember, I'm drying
the air so I'm forcing dry air through tools maybe it's an air wrench, maybe it's
a cylinder,
maybe it is some sort of a linear device working, so you can kind of have to, I'm sorry
pneumatic motor and so you kind of have to know what you're doing, so pushing putting
a little bit lubricating oil into the air allows it to keep the seals, keep any
type of lubrication going on so that it doesn't dry out. Dry air tends to dry
seals, those are the things that keeps you connector devices at the
ports and stuff, to keep the air out of it or keep the air in and keep
the pressure up. So lubricator is very important. Cylinder is a linear device
used to perform work. May be a single acting where compressed air moves the
device in one direction and a spring returns it. Or double acting where air pushes
the cylinder one way and then the directional control
valve moves adjusting it to put the air the other direction and usually there is an
exhaust muffler there to allow the air to escape while it does that. Air motor
is a rotating device used to perform work, it's just like an electrical motor
instead of electricity pushing the motor around, you are going to utilize air with the
veins, you're going to have veins. The veins catch the air, as the air is caught, it's
spins a shaft and hopefully in the end you have a pulley system or some sort of
mechanism to actually do the work for you.
You have filters, you have different types you have a coalescing filter which is
used to remove liquids from the compressed air and then a particulate filter
which is used to remove solids. Hosing and tubing is used for low-pressure
compressor systems, you would use hard for anything that's higher, usually less than
100 psi, you'd actually have hard tubing maybe copper, steel or anything lower than that
you can use hoses or flexible tubing to do that. ISO you've
heard this before International Organization for
Standardization, if I had a pneumatic set of plans here in front of me, they
would have certain types of symbols on it. Those symbols are maintained by the
ISO to make sure that its universal across the board.
Pressure regulating valve it can be an adjustable valve that adjust the
the pressure of the system.
Pneumatic controls they're series of valves or relays that uses low-pressure
to actually, in the control industrial equipment that actually does controlling
and make sure the valves come on maybe to adjust the directional control
valves maybe even conducts a flow control valves to make sure that I'm
getting the proper pressures in the proper air proper places to do the work
that I want to do using pneumatic controls. Pressure switch is an automatic switch that turns
on or off the device usually set a certain psi in this case we have a hundred
seventy-five set up here in our example but it can be any type. I have an air compressor at my
house I use it for certain tools air up car tires, mine is set up at a hundred
psi, the biggest thing I needed for is a nail gun, my nail gun operates at 95
psi. I so I know I'll always have at least 100 psi in my system usually any given time.
Pressure relief valve is a non adjustable safety valve required by OSHA
to release pressure if it gets over that set pressure switch. So like at my house I
have a pressure relief valve on my air compressor and the tank so that if it
sometimes I do hear it, it makes a loud swishing noise where you know the air is
escaping then usually happens the air compressor shuts off, the pressure
relief valve goes off,
lowering the pressure down to close to my preset pressure switch. Tube
fitting is commonly used in and systems to make tubing connections can be
compression style or push lock style, again these are tube fittings they made
tube connections from tube to tube, not tube to valve or not tube to pump, those are ports. I'm going to connect
those to ports. Alright when we're talking about pneumatics we definitely want to talk about
talking about psi we're talking about
creating pressure, we want to make sure we stay safe. So pneumatic safety is very
important, we want to make sure we use our proper personal protective equipment, PPE
including our hearing protection,
maybe it's using something you know goggles if I'm around a type of air tool that's
creating or could possibly create sparks or anything else, maybe even a face shield.
I don't want to have compressed air being blown on my face, definitely don't want it on my
body because remember there is of course the pressure itself but
also a little bit of oil in there too and I don't want that on a body as well.
As a safety guide use the holes or tubing on high pressure compressed air
over 50 psi should be kept very minimal, if a hose or tube is over four feet long it
should have its own shut off valve. That's just so that you can mitigate any types of
problems in there, has it's own shut off valve, you can shut it off, isolate the problem
without having to shut down the whole system. All pipes hoses and fittings of a system must
have a rating and that rating must be noted on the valve, the hoses or the fittings.
Hosing and tubing to be used in a system will have identification
marking that indicates the maximum working pressure, that's again WP, WP 045
psi or W or whatever the psi for that type of working for that condition. So
again that is it for pneumatics. It is a very cursory course, good luck on your quizzes
out there and see the next class, thank you.