Talleres F. Larrinaga

Talleres F. Larrinaga, S. L., en el marco del Programa ICEX Next, ha contado con el apoyo de ICEX y con la cofinanciación del fondo europeo FEDER. La finalidad de este apoyo es contribuir al desarrollo internacional de la empresa y de su entorno.

PRODUCTS: Quarter-turn Gear Operators for valves

Quarter turn gear operators TORQUE OUTPUT (Kg.m)


1 Kgm = 9,8070 Nm      1 Nm = 0,73756 lbf.ft     1 Nm = 8,8507 lbf.ins

General Description

“90” type operators are self-locking worm gears with a 90-degree turn and adjustable stops at ±5 degrees at each end. The input shaft where the handwheel is coupled is supplied with a key in accordance with our range of handwheels. This is provided with a position indicator.


These gearboxes can be used in services coupled to electric, pneumatic or hydraulic multi-turn actuators. When this is required, the gearbox has a flange and keyed-on spindle. FL5 and FL6 models can be motorized on request, as well as other types of flanges for all other models. Please contact us for more detailed information.


In order to reduce the input torque value and to obtain reasonable operating forces on the handwheel, FL-90-30, FL-90-31, FL-90-40, FL-90-50, FL-90-60 gearboxes can be fitted with a second reduction gear. On request they can be supplied with motor coupling according to ISO-5211. Please contact us for more detailed information.


These operators are fitted on valves that require 90-degree turns for their operation, such as ball valves, butterfly valves, plug valves, etc. These are designed for use outdoors in accordance with standard IP 67. The manufacturing quality of the gear unit complies with AGMA class 8. They can only be used in those valves that require turning torque without thrust.

All our gearboxes are coated according to UNE-EN ISO 12944-6 with a total thickness of 230µ allowing them to operate in a C5 marine atmosphere.

These operators are supplied with a flat mounting base according to the ISO-5211 standard.
See Annex C of the Installation and Maintenance Manual.
The quadrant is supplied solid. At the customer`s request, quadrants can be supplied with a bore and keyway machined in accordance with the diameter of the valve spindle. The position of this keyway must be indicated. Option, on request for square shaft.

The clockwise rotation of the input shaft generates a clockwise rotation of the output shaft.

On request, they can be manufactured with the input shaft on the other side.

The operators are lubricated with permanent grease.
The range of temperature for continuous operation is from -20 to +120 ºC.

Unless otherwise specified by the customer, these gearboxes are supplied without handwheel. A range of handwheels is available, which can be supplied with the gearbox on request. The customer will determine the diameter according to the tangential force to be obtained. See Installation and Maintenance Manual.

Other handwheel diameters can be supplied on request.

The applied torque depends on the tangential force applied to the handwheel and its diameter.

The RIM tangential force according to API standard for manual applications is 360 N (80 pounds of force), but most applications are sized for a RIM tangential force of 400 N.

Applied Torque = Applied Force x Flywheel Radius

Our gearboxes can be outfitted with a number of accessories. Please contact us for more detailed information.

All Talleres F. LARRINAGA model actuators are provided with their corresponding identification label.
For motorised gearboxes, it is very important to follow the instructions described in the installation and maintenance manual.

Once the operator has been mounted on the valve, the latter should not be raised by means of the operator.

In order to store the operators, proceed as follows:

  • Store in a clean dry place.
  • Protect the machined areas from shocks and rust.
  • Turn the input spindle several times every four months during storage.