Our actuators can be delivered as single- or double acting and can operate ball-, butterfly- and globe valves. The design simplifies maintenance and installation, which gives the customer a cost-effective product. Quarter turn actuators are delivered with adjustable stroke or fixed 90 degree rotation with mechanical locking.
Single acting, hydraulic actuator
Type: 1/4 turn hydraulic actuator
RE2 – Spring-to-close-action
RF2 – Spring-to-open-action
- Scotch-yoke design, piston type
- Adjustable stroke
- Local visual position indicator
- Stationary hand pump or quick connectors for portable hand pump
- Connection flange according to ISO 5211
Available torque up to 17800 Nm (Larger actuators on request)
Service temperature -20°C to +80 (+110°C upon request)
Double acting, hydraulic actuator
Type: 1/4 turn hydraulic actuator
RA2 – Mechanical locking
RB2 – Adjustable stroke
- Scotch-yoke design, piston type
- Local visual position indicator
- Manual operation by stationary hand pump or by portable hand pump via quick connectors
- Connection flange according to ISO 5211
Max hydraulic working pressure 220 bar
Actuator torque range 69 – 64550 Nm
Service temperature -45°C to +120°C
Use area: For dry and submerged purpose (for submerged type “SBM” a seal connection kit is added)
Pneumatic actuators, single acting
The actuator operates by a combination of force created by air and spring force.
Type: 1/4 turn pneumatic actuator
RA2 – Mechanical locking
RB2 – Adjustable stroke
- Scotch-yoke design, piston type
- Local visual position indicator or indicator box with different options
- Connection flange according to ISO 5211
- Max working pressure 12 bar
- Actuator torque range upon request
- Service temperature -20°C to +70°C
- Various sizes upon request
Pneumatic actuator, double acting
The actuator operates by force created by air.
Type: 1/4 turn Pneumatic actuator
RA2 – Mechanical locking
RB2 – Adjustable stroke
- Scotch-yoke design, piston type
- Local visual position indicator
- Connection flange according to ISO 5211
- Max working pressure 12 bar
- Actuator torque range upon request
- Service temperature -20°C to +70°C
- Various sizes upon request
Mechanical locking
All RA actuators are delivered with Mechanical Locking as standard. The mechanism is integrated in the actuator and totally independent of hydraulic oil. If there is loss of hydraulic pressure or even a fire, the valve will be kept safe in last position (open/close).
More details around mechanical locking
Hydraulic actuators of “scotch yoke” design with mechanical locking of the actuator in both end positions.
Skarpenord’s hydraulic actuators based on the “scotch-yoke” principle. The “scotch yoke” design allows a sturdy construction that ensures maximum performance under all conditions. Compared to other actuator designs, the risk of malfunction due to contaminated oil is greatly reduced allowing improved reliability at less maintenance. The design also allows the actuator’s plunger to be mechanically locked in both end positions. Consequently, the valve disc is mechanically locked in both open and closed position and cannot be turned by the forces normally created by excessive pressure or flow in the pipelines.
The mechanical locking works independently of the hydraulic oil pressure and thus eliminates the need for a “hydralock” – a double pilot-operated non-return valve in the actuator branch lines. Any extraordinary temperature compensating arrangement intended to keep the actuator in its end position is also unnecessary. A hydralock or any temperature compensating components depend a.o. on the cleanness of the hydraulic oil. Such extra components are avoided because of the actuator’s mechanical locking function, and the “scotch yoke” actuator ensures a reliable performance even with heavily contaminated hydraulic oil.
Easy maintenance
The Mechanical Locking gives the feature of Easy Maintenance as well. The only regular maintenance we recommend on Skarpenord actuators, is changing of the piston sealing. Because of the Mechanical Locking, the sealing can be replaced without any dismantling. The actuator can remain attached to the valve and the valve does not have to be disconnected from the pipeline. The maintenance can be performed with the valve safe locked in fully closed or open position. Full flow can be maintained in the pipeline during maintenance.
EAL™ Hydraulic Oil
Our VRC systems is also suited for use with EAL™ Hydraulic Oil and can be used upon customers preference. This is premium quality, high performance hydraulic oils developed to meet the demand for environmentally acceptable hydraulic fluids