Safety in pneumatic circuits - PHARM Connectpharmconnect.eu/uploaded/thomas_schulz_festo.pdf ·...

Pharm connect congress 2014

Budapest Feb. 26. – 27.

Thomas Schulz

Head of ISM and KAM Biotech/Pharma

Phone: +49-711/347-52192

Mail: [email protected]

Safety in pneumatic automation

Thomas Schulz / CP-KB Pharm connect congress Budapest 2014 1

Safety in pneumatic automation

Presentation

1. General information about Festo

2. Legal Regulations - Specifics for Factory- and Process-Automation

3. Risk analysis - risk assessment - risk reduction

4. Safety Functions Categories (input logic output)

5. Applications

• Increased safety for double acting valves – defined safety position

• Increased safety for single acting valves – quick exhausting

• Combined safety measures by pressure zones and quick exhaust valves


Festo – an independent family-owned company


Some Facts & Figures

• Pneumatic & Electric Automation

Technology offering solutions for

Factory & Process Automation

• Learning Systems,

Training & Consulting

• Turnover 2,3 billion € (2013)

• 61 international Festo companies

• 300.000 Customers worldwide

• 30.000 Components

in countless variants

• 16.000 Employees worldwide

• Investments in % of turnover:

R&D: 7,0 %

Training: 1,5 %

Festo Technology Centre and

Headquarters , Esslingen, DE

Festo Customer Service Centre

and production plant, St. Ingbert, DE

Legal regulation – Risk assessment


Laws e.g. EC Machinery Directive 2006/42/EC

Risk assessment

Risk analysis Risk assessment Risk reduction

Design measures

Technical measures

User information

Evaluation : PL ≥ PLr SIL ≥ SILr

Safe machines

Evaluation and

assessment of technical

safety measures

Standardized process

+

„check list “

Risk reduction

Evaluation whether

risk reduction is sufficient

Safety function Input Logic Output

Risk Analysis – Determininig the performance level


S Severity of injury

S1 Slight /Normally reversible injury

S2 Serious (normally irreversible

injury, including death

F Frequency and/or duration of

exposure to the hazard

F1 Seldom to less often or brief

F2 Frequent to continuous and/or

long

P Possibility of avoiding the hazard

P1 Possible under specific conditions

F2 Scarcely ever possible

a – e Performance level PL

DIN EN ISO 13849-1 Appendix 1.2.3

a

b

c

d

e

Signalling structure - categories


Category B and Category 1

Signal 1 channel

Failures will not be detected 0 fault safety

Category 1 uses only “prooven components“

Input Logic Output Input-

signal

Output-

signal



Category 2

• Additional testing and monitoring failure detection possible

• 100x test of the function before the request by the machine control System

• No permanent fault monitoring 0 fault detection between the test phases

Input Logic Output Input signal Output signal

Test signal Monitoring

Logic Output

Monitoring Trigger signal

Second path for shut down

or indication



Category 3

• Signals via 2 channels

• Some, but not all faults are detected before or during the next request

• 1 Fault safety multiple undetected faults lead to the loss of Safety function

Input Logic Output Input signal

Output signal

Test signal

Monitoring

Logic Output Input Output signal Input signal

Monitoring



Category 4

• Signals via 2 channels

• Every fault must be detected before or during the next request

• 1 Fault safety

Input Logic Output Input signal

Output signal

Test signal

Monitoring

Logic Output Input Output signal Input signal

Monitoring



Category B and Category 1 Category 3

Category 2 Category 4

Risk Assessment PL vs. SIL


a

b

c

d

e

1

2

3

Cat. B Cat. 1 Cat. 2 Cat. 4 Cat. 3

MTTFd = Mean Time To Failure (dangerous) High Demand Mode

Probability of failure (per hour)

max. failure

Performance level PL Safety Integrity Level SIL

Applications - Plant and machine safety


Machine directives and safety procedures request in many cases a safe shutdown of

machines and process equipment in case of an emergency. To increase plant safety

the following technical measures can be implemented:

1. Double acting valves (DA)

Bring the valve to a defined position with the right pneumatic functions

2. Single acting valves (NC or NO)

Quick exhausting of an emergency to prevent unintended actuation of a process

valve due to back pressure and pressure peaks in the system

3. Application: Filling station for powder

Combined safety measures by pressure zones on a valve terminal and quick

exhausting

Increased safety for double acting valves – defined safety position


• Double acting valves or cylinders have no defined safety position. In case of a shutdown or emergency this might cause a problem.

• A defined safety position can be integrated pneumatically by either holding the pressure in the actuator or exhausting it.

Exhausting

Pressurizing

Increased safety for double acting drives – defined safety position


Double acting cylinder <Safety operation> <Compressed air + voltage available>

1

Action : when applying compressed air, cylinder moves to safety

position


Double acting cylinder <Safety operation> <Compressed air + voltage applied>

Action : cylinder is forced into

safety position

2


19

Double acting cylinder <Safety Operation> <Supply voltage ON, Step 1>

Action : electromagnetic valve ON

(„Enable“)

3


20

Double acting cylinder <Safety Operation> <Supply voltage ON, Step 2>

Action : pneumatic valves ON

(„Enable“)

4


21

Double acting cylinder <Safety Operation> <Cylinder positioning>

Action : 5/3-valve „move right“

5


22

Double acting cylinder <Safety Operation> <Cylinder positioning>

Action : 5/3-valve „move left“

6


23

Action : supply voltage OFF

Double acting cylinder <Safety Operation> <Supply voltage failure, Step 1>

7


24

Action : electromagnetic valve OFF


8


25


Action : pneumatic valves OFF,

cylinder moves to safety position

9


26


Action : Cylinder is forced into

safety position

10


Increased safety for single acting valves – quick exhausting


In case of an emergency single acting valves will fall back into their defined safety position. Normally the pneumatic system will remain under pressure. Accidently triggered pressure peaks might actuate a process valve possible risk

• Additional safety can be achieved by:

o Include a quick exhausting valve in the pneumatic system. In an emergency shut down the pneumatic system will be exhausted quickly.

o Include an integrated locking device for protection against unexpected start up

Increased safety for single acting valves – quick exhausting


The highest safety for this application can be reached e.g. with MS-6-SV-E or MS-6-SV-E-ASIS

Cat. 4

PL e

Diagnostic coverage Integrated, internal sensing

of the piston position

Channels 2

Certificate IFA

Safety component to

MD 2006/42/EC

YES

Powder filling station


Zone 1

Zone 2

System without pressure

Flexible bag holder

and sealing

Open/close of

powder supply

Pressure build up and

quick exhaust valve

Redundant signal cable

for quick exhaust valve



Zone 1

Zone 2

Zone 1

Zone 2

System under pressure

and working

Redundant signal cable

for quick exhaust valve



Zone 1

Zone 2

Zone 1

Zone 2

System under pressure

and working

Emergency stop or

signal missing



Zone 1

Zone 2

Zone 1

Zone 2

System partly under

pressure and working

1. Actuator for powder

supply exhausting and

closing

2. Bag holder and sealing

still working



Zone 1

Zone 2

Zone 1 System partly under

pressure and working

1. Powder supply closed

2. Bag sealing still working

Safe operation according to

“PL e” possible

Further information


Safety poster

Safety engineering brochure

Contact Data


Thomas Schulz

Head of Key Account Management

and Industry Segment Management

Biotech/Pharma/Cosmetics

+49 (0) 711 347 52192

[email protected]

Safety in pneumatic circuits - PHARM Connectpharmconnect.eu/uploaded/thomas_schulz_festo.pdf ·...

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