Pneumatics

Pressure for pneumatics is usually measured in PSI or BAR or Kg/cm²
psi - Pounds per Square Inch
or
bar - 1 bar is the average atmospheric pressure at sea level
1 Bar = 14.5037738 psi
so 1 bar = approx 14.5 psi
For our purposes 1 bar = 15 psi is near enough
or
Kg per square centimetre
1 inch is 2.54 cm, 1 Kg is 2.2 lb (pounds)
14.5 psi => 14.5/2.54/2.54/2.2 => 1.02 Kg per square centimetre
so for our purposes
1 bar = 1 Kg/cm²
or
KPa - Kilo Pascals - 1 Pascal is 1 Newton per square Metre
Scientists and some people who want to impress you will talk about pressure in Pascals
1 pascal is equal to 0.000145037738007 psi
1 Pascal is 1 Newton per square Metre
For meaningful use for pneumatics a pressure in Pascals has to be in KiloPascals KPa
1 Bar = 101.325 KPa

Pneumatics fittings

A bank of five 24volt Spool valves on a 6 position Manifold
note one position is blanked off at the RHS.
The main air inlet and exhaust are at the ends,
the individual air connections to each valve are at the front.

Two Poppet valves
On the left is a 3 port valve with Inlet, Supply to aa Actuator, and Exhaust at the top.
On the right is a 2 port valve with Inlet and Supply. Exhaust requires a separate valve.

The port markings for the 3 port valve -
"P" (Pressure ?) for air supply Inlet
"A" ((Actuator ?) for supply to an Actuator
"R" (Release ?) for Exhaust

Quick release connectors
top - Mainland Europe - DIN standard?
bottom - the type mainly used in the U.K.

Actuators
top - an air Muscle
bottom - two cylinder actuators, one with the piston rod extended
The force with which an Air Muscle pulls is proportional to the surface area of the muscle and the air pressure.
The force exerted by a piston rod is the area of the piston x the air pressure
The retraction force will be less than the extending force because the piston rod takes up some area.

Various fittings
top - 5mm Banjo, 5mm straight, 1/8" BSP, 1/4" BSP, 1/4" BSP for bigger tubing.
bottom - a 6mm to 4mm convertor, a 4mm and two 6mm blanking plugs, a 6mm Equal T, a 4mm Equal T, and a 6mm R/A.
The black plastic on the Banjo fitting can rotate on the brass end which is screwed into the valve etc.
5mm fittings can be got to take 4mm, 5mm and 6mm tube.
1/8" BSP can be got for all the smaller sizes of tube,
1/4" BSP can be got for most sizes of tube,
BSP - British Standard Pipe. the size refers to the usual bore of the pipe when the standards were made.
[Paintball fittings are usually American NPT (National Pipe Thread) and don't quite fit BSP fittings]
The 5mm size is a parallel thread and has a sealing washer at the top.
The 1/8" and 1/4" fittings have tapered threads and mostly come with PTFE sealing tape already fitted.
For some appllications BSP fittings can be got with parallel threads and a sealing washer at the top - they don't mate with tapered threads.

Tools
PTFE tape, Tubing Cutter, Tool for pressing the release rings on tube fittings.

Tap, Regulator, Restrictor

Regulator dial for a 0-11 bar regulator

Regulator dial for a 0-7 Kg/cm² (0-7 bar) regulator
DO NOT use a gauge or regulator for more than its rating - it will be damaged.
The red pointer is just for human use.