Design/Selection - SMC Networks MGC Seires Operation Manual

8. Design/Selection

1) Confirm the specifications.
Products represented in this catalog are designed only for use in compressed air systems (including vacuum).
Do not operate at pressures, temperatures, etc., beyond the range of specifications, as this can cause damage
or malfunc tion. Please contact SMC when using a fluid other than compressed air made by pneumatic
equipment (including vacuum). We do not guarantee against any damage if the product is used outside of the
specification range.
2) Confirm the applicable specification range.
The cylinder specifications listed in the catalog apply to standard strokes, including intermediate strokes.
Please consult with SMC for specifications on long strokes. There are also some made-to-order products (-XB□
/-XC□) for which product specifications do not apply.
3) There is a danger of sudden action by cylinders if the sliding parts of machinery are twisted, etc.,
or changes in forces occur.
In such cases, human injury may occur, e.g. by hands or feet getting caught in the machinery, or damage to the
machinery itself may occur. Therefore, the machine should be designed to operate smoothly and to avoid such
dangers.
4) If there is a chance that the product will pose a hazard to humans, install a protective cover.
If the moving portion of the product will pose a hazard to humans or will damage machinery or equipment,
provide a construction that prevents direct contact with those areas.
5) Be certain that the secured portions will not loosen.
Be certain to adopt a reliable connecting method if the cylinder is used very frequently or if it is used in a
location that is exposed to a large amount of vibration.
6) Consider the possibility of a power source related malfunction.
For equipment that relies on power sources such as compressed air, electricity, or hydraulic pressure, adopt a
countermeasure to prevent the equipment from causing a hazard to humans or damage to the equipment in the
event of a malfunction.
7) Design the circuitry to prevent the sudden lurching of driven objects.
When a cylinder is driven by an exhaust center type directional control valve or when starting up after residual
pressure is exhausted from the circuit, etc., the piston and its driven object will lurch at a high speed if
pressure is applied to one side of the cylinder because of the absence of air pressure inside the cylinder.
Therefore, select equipment and design circuits to prevent sudden lurching because there is a danger of human
injury and/or damage to equipment when this occurs.
8) Consider the action of the cylinder in the event of an emergency stop.
Devise a safe system so that if a person engages the emergency stop or if a safety device is tripped during a
system malfunction, such as a power outage, the movement of the cylinder will not cause a hazard to humans or
damage the equipment.
9) Avoid synchronized operation using cylinders only.
Even if multiple pneumatic cylinders are initially set to the same speed, their speeds may vary due to changes in
operating conditions. Therefore, avoid designs where a single load is moved by synchronizing multiple cylinder
operations.
10) Consider the action of the cylinder when restarting after an emergency stop.
Devise a safe design so that the restarting of the cylinder will not pose a hazard to humans or damage the
equipment. Install manually controlled equipment for safety when the actuator has to be reset to the starting
position.
11) Intermediate stops
When an intermediate stopped position is performed with a 3position closed center type/double check valve
type directional control valve, it is difficult to achieve accurate and precise stopped positions due to the
compressibility of air.
Furthermore, since valves and cylinders are not guaranteed for zero air leakage, it may not be possible to hold a
stopped position for an extended period of time. Please contact SMC in case it is necessary to hold a stopped
position for an extended period of time.
12) Do not disassemble the product or make any modifications, including additional ma chining.
Doing so may cause human injury and/or an accident.
13) Refer to the Auto Switches Precautions for us ing with an auto switch.
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