SIL Safety Manual
SM-025-GVO Rev. 0
November 2017
9
Section 5: Service Condition Limitations
Service Condition Limitations
Section 5: Service Condition Limitations
(limitation of use)
The designer of an SIF must check that the product is rated for use within the expected
application limits. The operating conditions limits strongly depend on the actuator type and
on its construction materials.
Operating pressure values are defined for each actuator.
Temperature limits are the following:
•
Standard ambient temperature range: -30°C to +100°C
•
Extended ambient temperature range: -60°C to +200°C (special versions)
Supply medium: instrument air, nitrogen or sweet gas (sour gas special version is available).
If GVO-CLP-SR/FS actuator is intended to be used outside the application limits or with
incompatible materials, the reliability data provided in the present document are invalid.
•
The actual environmental conditions are included on the actuator nameplate
•
The chose values are valid for the lifetime specified in Section 6.
•
Manual override
Normally, the GVO-CLP-SR/FS actuators can be fitted with one of the following types of
manual overrides:
•
MHW Manual Hand-wheel mounted on the end flange of the pneumatic cylinder
•
MHP Manual Hydraulic override including an additional hydraulic cylinder with
manual pump and distributor
With reference GVO-CLP-SR/FS actuator, the mechanical manual override can be done with
three configuration depending of the actuator size:
The use of a manual override is not recommended in a SIL classified application, as it results
in a bypass of the safety function.
In case the manual override is used, the following requirements must be fullfilled, or the
Functional Safety Certification will become invalid:
1.
The users authorized to operate on the actuator shall be skilled personnel;
2.
The maximum duration of bypass shall be defined (responsibility of the final user).
3.
If necessary, compensatory measures to allow the safe operation of the process
shall be defined (responsibility of the final user).
4.
Before selecting remote operating mode control of actuator, the manual override
must be disengaged according to IOM Manual. The position selected
(remote/automatic control or local / manual control) can be achieved with a
specific technical solution that does not allow to reach an intermediate position
lever’s and avoids unintentional activation.
5.
The engagement of the manual override shall be signalled, at least locally,
according to IOM Manual. As optional request from final user, to determine if the
manual override is engaged, an electrical signal using contact switching can be
provided to communicate the status to the control room.
