Flowserve LPS Series Heavy-Duty Actuators - Manual (Page 3)

1 Safety Function Specification
The safety function used in LPS Actuator Series is defined
as follows:
Single acting actuator:
a. When an unsafe condition is detected in a plant by a
process sensor, the controller, via the control panel,
drives the Actuator to close the shut-down valve,
normally de-energizing a solenoid valve, and venting
air via the control system, OR
b. When an unsafe condition is detected in a plant by a
process sensor, the controller, via the control panel,
drives the Actuator to open the shut-down valve, normally
de-energizing a solenoid valve, and venting air via the
control system.
Double acting actuator:
a. When an unsafe condition is detected in a plant by a
process sensor, the controller, via the control panel,
drives the Actuator to close the shut-down valve,
depressurizing the OPEN chamber of the cylinder and
pressurizing the CLOSE chamber, OR
b. When an unsafe condition is detected in a plant by a
process sensor, the controller, via the control panel,
drives the Actuator to open the shut-down valve,
depressurizing the CLOSE chamber of the cylinder and
pressurizing the OPEN chamber.
The choice of the safety function to be implemented is
responsibility of the system integrator.
2 Configuration of the Product
The LPS Actuator Series is composed by pneumatic, single
acting (spring return) LPS-SA or double acting LPS-DA
actuators designed to operate several types of quarter-turn
valves.
The LPS-SA actuators can be assembled in the ‘fail to open’
or ‘fail to close’ configurations.
Actuator design characteristics are shown on the data plate
attached to the actuator.
The LPS-SA actuator series is available in a wide torque
range. The torque ratings of this actuator series are specified
in the document: “PRESSURE-TORQUE CHARTS LPS
SINGLE ACTING ACTUATORS” (doc. n° DUT008-LPS-SA”,
Draft Document).
The overall dimensions of the LPS-SA actuator series, their
weight, the number of available models and all the available
constructive options are listed in the documents:
“dim-data_LPS_SA_FC”, “dim-data_LPS_SA_FO”,
“Weight SA” and “Selection table” (Draft Documents).
3 Service Condition Limitations
(Limitation of Use)
The limits of operating conditions strongly depend on the
Actuator type and on materials of construction; operating
limits of temperature and pressure are indicated in the
following table:
Operating Condition Range
Pressure
Design pressure = 12 barg
(MOP* depending on actuator size)
Tmin
- 29°C
(-60°C with special seals)
Tmax
100°C
(160°C with special seals)
*MOP = Maximum Operating Pressure, as per ISO12490.
The service condition limitations (Max Rated Pressure,
Temperature range, ... ) are included on actuator label
(see below).
Figure 1: LPS Actuator Nameplate
3
LPS Series Heavy-Duty Actuators FCD LPS-SM-00 – 1/14