Double-acting and spring-return pneumatic quarter-turn

actuators for on-off and modulating control of valves in

heavy-duty service. Available for output torques to

1.000.000 Nm.

General Application

ALGA, ALGAS and ALGAS-QA pneumatic actuators are

designed for on-off or modulating control of quarter-turn

ball, butterfly, plug or damper style valves.

Features

• Totally enclosed, weatherproof housing in fabricated

carbon steel for maximum strength.

• Guide bar resists transverse loads and supports the

piston rod.

• Hard chromium plated alloy steel material guarantees

corrosion protection and minimal friction.

• Polytetrafluoroethylene (PTFE)-impregnated bronze or

sintered bronze bushings provide minimal friction and

extended service life.

• Scotch yoke design with canted or symmetric torque arm

allows close working to distinctive valve torque profiles.

• External travel stops for precise angular stroke

adjustment 90° ±4° at each end of travel.

• Electroless nickel plated and polished cylinder provides

maximum corrosion resistance and reduces friction.

• Floating type piston seals provide low hysteresis and

high sensitivity, preventing sticking problems.

• ALGAS spring-return pack incorporates up to four

springs, fully encapsulated in a factory welded cartridge

ensuring personnel safety and simplifying assembly.

• ALGAS spring action can be changed easily in the field

from to close to open or vice versa.

• Special coatings for offshore or corrosive environments.

Installation

The actuator can be mounted parallel or perpendicular to pipeline. The actuator can

be installed in any convenient position including vertical, horizontal or upside down.

1.Bolt mounting bracket to actuator hand tight. Do not tighten yet.

2.Install coupling on valve. Be sure rotary stops on valve are removed or

adjusted to allow actuator stops to do the stopping.

3.Install actuator and bracket to valve being sure to leave all fastener

connections hand tight. If possible, stroke valve and actuator to a half open

position 45° and physically shift actuator back and forth until coupling and

all fasteners are relaxed then tighten all bolts and nuts. This procedure will

accurately align valve stem to actuator output shaft and prolong valve stem

seal life. Lift the actuator at a balance point near the center housing. Do not

lift the weight of the valve, see Figure 1.

4.Cycle valve/actuator assembly and observe for smooth operation.

5.Adjust travel stops for perfect alignment in both open and closed positions.

NOTICE

If jackscrew override is installed, please refer to Section 3 for stroke adjustment.

6. Tubing connections – some models utilize two pistons for added power.

Spring-return (single-acting) dual cylinder designs require one “jumper”

to make the supply port common on both pistons. Double-acting (air to air)

dual cylinder designs require two “jumpers”. Refer to Figure 2 for

typical arrangement.

Introducing the Actuator

The hydraulic actuator series OLGA-H was engineered and is manufactured to provide

maximum torque output with minimum supply pressure. The OLGA-H actuators

are suitable for any quarter turn application such as ball, plug, butterfly valves or

dampers, in both on/off and modulating heavy-duty service.

The actuator (see Figure 4) is made up of a weatherproof scotch yoke mechanism

transforming the linear movement of the pneumatic cylinder (on closing or opening)

into the rotary movement, which is necessary for operation. The angular stroke of

the yoke is adjustable between 82° and 98° by means of the external mechanical

stops screwed into the left wall of the mechanism housing and into the end flange

of the pneumatic cylinder. The cover of the scotch yoke mechanism is arranged

for the assembly of the required accessories (positioner, signalling limit switches,

position transducer, etc.) by means of proper matching units. The above mentioned

accessories are operated by the actuator drive sleeve. The housing of the scotch yoke

mechanism has a flange with threaded holes to fix the actuator to the valve either

directly or, if required, with the interposition of an adaptor flange or a mounting

bracket. The actuator yoke has a hole with keyways suitable for the assembly of an

insert bush the internal hole of which is machined (by Biffi or at customer care),

according to the shape and dimensions of the valve stem. Biffi can supply different

types of control system following customer’s requirements.

Terms and Conditions

Biffi guarantees that all the items produced are free of defects in workmanship and

manufacturing materials and meet relevant current specifications, provided they are

installed, used and serviced according to the instructions contained in the present

manual. The warranty can last either one year from the date of installation by the

initial user of the product, or eighteen months from the date of shipment to the initial

user, depending on which event occurs first. All detailed warranty conditions are

specified in the documentation forwarded together with the product. This warranty

does not cover special products or components not warranted by subcontractors,

or materials that were used or installed improperly or were modified or repaired

by unauthorized staff. In the event that a fault condition be caused by improper

installation, maintenance or use or by irregular working conditions, the repairs will be

charged according to applicable fees.

The warranty and Biffi liability shall lapse in the event that any modification or

tampering whatsoever be performed on the actuator.

Electrostatic Charge

An electrostatic charge risk is present on the actuator surface; in case of cleaning,

use only antistatic cloth; in case of maintenance, avoid all rubbing/frictions that could

electrostatically charge the equipment.

Features

• Totally enclosed, weatherproof housing in fabricated carbon

steel for maximum strength.

• Guide bar resists transverse loads and supports the

piston rod.

• Hard chromium plated alloy steel material guarantees

corrosion protection and minimal friction.

• Polytetrafluoroethylene (PTFE)-impregnated bronze or

sintered bronze bushings provide minimal friction and

extended service life.

• Scotch yoke design with canted or symmetric torque arm

allows close working to distinctive valve torque profiles.

• External travel stops for precise angular stroke adjustment

90° +/- 4° at each end of travel.

• Electroless nickel plated and polished cylinder provides

maximum corrosion resistance and reduces friction.

• Triple-element piston seals provide low friction, high

sensitivity, ensure long life and prevent sticking problems.

• OLGAS-H fully encapsulated spring-return pack ensures

personnel safety and simplifies assembly.

• OLGAS-H modular design enables spring action to be

changed in the field easily.

• OLGAS-H QA is the quick-acting spring-return hydraulic and

electro-hydraulic actuators with high flow rate manifold and

cylinder, integral quick exhaust valves, and end-of-stroke

damper systems, designed by Biffi.

• OLGAS-H QA achieves “safe” position in less than 0.3 second.

This configuration can be provided with a double camber

option and the name will add the suffix DC at the end.

Double-acting and spring return hydraulic quarter-turn actuators for

ON/OFF and modulating control of valves in heavy-duty service suitable

for high pressure supply. Models available for output torques to 750.000 Nm.

General Application

OLGA-H and OLGAS-H series hydraulic actuators are designed for the

control of quarter turn ball, butterfly, plug or damper style valves.

Technical Data

Design Pressure (MAWP)

OLGA-H/OLGAS-H

With standard CS:

352 barg maximum (based on actuator model,please contact the

factory to receive confirmation)

With optional SS: Please contact the factory

OLGAS-H-QA: Contact factory

MOP

With standard CS tie rods:  Refer to torque table

With optional SS: Please contact the factory

Supply medium: Hydraulic oil, special versions for fire resistant fluids

Output Torque

OLGA-H: Double-Acting torque up to 750.000 Nm

OLGAS-H/QA:

Spring starting torque up to 335.000 Nm

Spring ending torque up to 235.000 Nm

Higher values available with special versions

Ambient Temperature

Standard range: -20 to +100 °C / -4 to +210 °F

Extended range: -60 to +100 °C / -70 °F to +210 °F

MAWP: 

Maximum Allowable Working Pressure is the pressure defined

for the design of the actuator pressure containing parts.

MOP: 

Maximum Operating Pressure is pressure that generates the torque

used to engineer the mechanical loaded parts of the actuator and

it is the one required to produce the Maximum Operating Torque

(MOT) of the actuator.