| |
| |
| Sizing example of Spring Return AT actuator (see also technical data): |
| |
 |
| FIG. SR07 |
| |
 |
| FIG. SR08 |
| |
| |
- SPRING TO CLOSE WHEN AIR FAILS (Balanced Torque) see also the Fig. SR07.
Published ball valve torque = 80 Nm
Safety factor (20%) = 80 Nm + 20% = 96 Nm
Air supply pressure available = 5 bar
|
The spring return AT actuator selected is AT400 S10, because it produces the
following values:
spring stroke 0° = 105 Nm
spring stroke 90° = 165 Nm
air stroke 0° = 172 Nm
air stroke 90° = 112 Nm
|
| |
| |
- SPRING TO CLOSE WHEN AIR FAILS (Unbalanced Torque) see also the Fig. SR08.
Published butterfly valve torque = 45 Nm
Safety factor (20%) = 47 Nm + 20% = 56.4 Nm
Air supply pressure available = 5.5 bar
|
| |
The spring return AT actuator selected is AT300 S12, because it produces the
following values:
spring stroke 0° = 60.8 Nm
spring stroke 90° = 94.5 Nm
air stroke 0° = 85.4 Nm
air stroke 90° = 51.7 Nm
|