HLAS – Single acting hydraulic linear actuator

Use and maintenance manual

HLAS
SINGLE ACTING SPRING-
RETURN HYDRAULIC
LINEAR ACTUATOR
MAN 620

Use and maintenance manual

4 18/02/19 Updated data-plate Sassi Orefici Vigliano
Updated applicable
3 18/04/16 regulation (chapter 1.1.1) Ermanni Orefici Vigliano
2 31/07/12 General update Ermanni Stoto Vigliano
1 25/06/10 General update Ermanni Stoto Vigliano
0 05/05/99 Document release Lazzarini Aliani Ziveri
Rev. Date Description Prepared Checked Approved

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TABLE OF CONTENTS
1 General warnings ................................................................ 4
1.1 Generalities ................................................................................. 4
1.1.1 Applicable regulation ............................................................... 4
1.1.2 Terms and conditions .............................................................. 4
1.2 Identification plate ....................................................................... 5
1.3 introducing the actuator ............................................................... 5
1.4 data sheet ................................................................................... 7
2 Installation ........................................................................... 7
2.1 checks upon actuator receipt ...................................................... 7
2.2 actuator handling ......................................................................... 7
2.3 storage ........................................................................................ 9
2.4 actuator assembly on the valve ................................................... 9
2.4.1 Types of assembly .................................................................. 9
2.4.2 Assembly procedure................................................................ 9
2.5 hydraulic connections ................................................................ 13
2.6 electrical connections (if any) .................................................... 13
2.7 commissioning........................................................................... 14
3 Operation and use ............................................................. 15
3.1 operation description ................................................................. 15
3.2 residual risks ............................................................................. 16
3.3 operations (examples) ............................................................... 16
3.4 calibration of the linear stroke.................................................... 18
3.5 calibration of microswitches (if foreseen) .................................. 20
3.6 calibration of the operation time ................................................ 22
4 Operational tests and inspections...................................... 23
5 Maintenance ...................................................................... 24
5.1 periodic maintenance ................................................................ 24
5.1.1 Check and restore oil level in the manual hand-pump........... 25
5.2 Extraordinary maintenance ....................................................... 26
5.2.1Lubrication of mechanism ............................................................. 26
5.2.2 Replacing the seals of the cylinder ........................................ 27
5.3 Dismantling and demolition ........................................................ 32
6 Troubleshooting ................................................................ 33
6.1 failure or breakdown research ................................................... 33
7 Layouts .............................................................................. 34
7.1 Spare parts order ...................................................................... 34
7.2 parts-list for maintenance and replacing procedure................... 35
8 Date report for maintenance operations ............................ 41

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NOTE:
BIFFI Italia S.r.l pays the highest attention to collecting and verifying the
documentation contained in this user manual. However BIFFI Italia S.r.l. is not
liable for any mistakes contained in this manual, for damage or accidents due to
the use of the latter. The information contained is of exclusive reserved ownership
of BIFFI Italia S.r.l and may be modified without prior notice. All rights reserved.

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1 General warnings
The manual is an integral part of the machine, it should
be carefully read before carrying out any operation and
it should be kept for future references.
1.1 GENERALITIES
BIFFI Italia S.r.l actuators are conceived, manufactured and
controlled according to the Quality Control System in compliance with
EN-ISO 9001 international regulation.
1.1.1 Applicable regulation

EN ISO 12100:2010: Safety of machinery – General principles for

design – Risk assessment and risk reduction
2006/42/EC: Machine directive.
2014/68/EU: Directive for pressure PED equipment
2014/35/EU: Directive for low voltage equipment
2014/30/EU: Directive for the electromagnetic compatibility
2014/34/EU: Directive and safety instructions for use in
hazardous area

1.1.2 Terms and conditions

Biffi Italia srl 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 Italia srl
liability shall lapse in the event that any modification or
tampering whatsoever be performed on the actuator.

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1.2 IDENTIFICATION PLATE

It is forbidden to modify the information and the marks without
previous written authorization by BIFFI Italia S.r.l.
The plate fastened on the actuator contains the following information
(Figure1).

Figure 1 – Data plate

1.3 INTRODUCING THE ACTUATOR

HLAS single acting hydraulic linear actuators, are suitable for the
operation of linear valves ( wedge gate valves, through conduit gate
valves) for ON-OFF and modulating heavy-duty service.
The actuator is made up of an hydraulic cylinder, a spring cartridge
and a mounting pedestal complete with a joint for the coupling to the
valve stem of actuator output stem. The valve is actuated in opening
and in closing position by the actuator hydraulic cylinder in one
direction and by the spring unit in the other direction.
The output thrust of spring unit can be downward or upward
according to valve operation requirements ( spring to open, spring to
close, direct acting valve , reverse acting valve).
The spring return pack incorporates up to four spring , fully
encapsulated in a factory welded cartridge: this assures safety
conditions to personnel and simplifies the assembly.

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The linear stroke of the valve is adjustable by means of the external

mechanical stop for upward position and by the adjustment of the
coupling of valve stem to actuator joint for the downward position.
The actuator pedestal has a flange with threaded holes to fix the
actuator to the valve.
BIFFI can supply different types of control system following
Customer’s requirements.

The expected lifetime of actuator is approximately 25 years .

Lifting eyelets

Hydraulic cylinder

Spring cartridge

Manual Hand-Pump
MHP (optional)

Valve position indicator

Valve coupling

Figure 2 – Identification of actuator parts

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1.4 DATA SHEET

Supply fluid Mineral oil or synthetic fluids
Operating temperature Standard: from –30°C to +100°C
Optional: from –60° to +140°C
Applications Gate, Globe valves

2 Installation
2.1 CHECKS UPON ACTUATOR RECEIPT
❑ Check that the model, the serial number of the actuator and the
technical data reported on the identification plate correspond with
those of order confirmation (Sect. 1.2).
❑ Check that the actuator is equipped with the fittings as provided for
by order confirmation.
❑ Check that the actuator was not damaged during transportation: if
necessary renovate the painting according to the specification
reported on the order confirmation.
❑ If the actuator is received already assembled with the valve, its
settings have already been made at the factory.
If the actuator is delivered separately from the valve, it is
necessary to check, and, if required, to adjust, the settings of the
mechanical stops (Sect. 3.4) and of micro-switches (if any) (Sect.
3.5).

2.2 ACTUATOR HANDLING

The lifting and handling should be made by qualified staff

and in compliance with the laws and provisions in force.

The fastening points are appropriate for the lifting of the

actuator alone and not for the valve + actuator assembly.
Avoid that during the handling, the actuator passes above
the staff.
The actuator should be handled with appropriate lifting
means. The weight of the actuator is reported on the
delivery bill.
Picture 1 – Lifting points for HLAS actuators

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1 = Lifting points ( obligatory )

Picture 2 - Positioning by chains

1 = point of support - 2 = don’t lay the actuator on tie-rods of
cylinder 3 = don’t lay the actuator on accessories ( manual
hand-pump, hydraulic control system etc. )

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2.3 STORAGE
If the actuator needs storage, before installation follow these steps:
❑ Place it on a wood surface in order not to deteriorate the area of
valve coupling.
❑ Make sure that plastic plugs are present on the hydraulic and
electrical connections (if present).
❑ Check that the cover of the control group and of the limit switch box
(if any) are properly closed.
If the storage is long-term or outdoor:
❑ Keep the actuator protected from direct weather conditions.
❑ Replace plastic plugs of hydraulic and electrical connections (if any)
with metal plugs that guarantee perfect tightness.
❑ Coat with oil, grease or protection disc, the valve coupling area.
❑ Periodically operate the actuator (Sect. 3.3).
2.4 ACTUATOR ASSEMBLY ON THE VALVE

2.4.1 Types of assembly

The adapter pedestal in fabricated carbon steel is specifically

designed for adaptation to any type of valve with provision for local
indicator, limit switches and other accessories (on request).

Lift the actuator by safety-hook for chains using the lifting-points (see
sect. 2.2) on the top of actuator for handling, transporting and
assembling in vertical position (see picture 1). For handling,
transporting and assembling the actuator in horizontal position by
safety-hook for chains use the lifting-points on the top of cylinder
head-flange and on coupling flange (see picture 2).

2.4.2 Assembly procedure

Failure to comply with the following procedures may

impair product warranty. Installation, commissioning
and maintenance and repair works should be carried
out by qualified staff.
A non-conforming assembly could be the source of
serious accidents.

For actuator assembly on the valve:

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Check that the assembly position, as shown on the

documentation, complies with system’s geometry.
Check the consistency of the parts of actuator-valve
coupling.

A) TO ASSEMBLE THE ACTUATOR ONTO THE VALVE BY BRACKET

WITH THREADED JOINT PROCEED AS FOLLOWS:

1) Check that the coupling dimensions of the valve flange and stem,
or of the relevant extension, meet the actuator coupling
dimensions (valve stem and flange). Lubricate the valve stem with
grease in order to make the assembly easier.
2) Connect a sling to the support point of the actuator and lift it.
To make easier the assembly , the valve stem has to be in perfect
vertical position.
Note: the eyebolt is sized for the lifting of the only actuator (NOT
ACTUATOR+VALVE). Proper lifting points have to be foreseen for
the valve.

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3) . Screw the actuator coupling joint onto the valve by rotating the
actuator, or screw down the valve stem stroke-ring with Red
Loctite 542 and fix the half-bearings. When the threaded holes of
the actuator flange are in correspondence with the holes on the
valve flange screw the proper stud bolts. Screw the nuts on the
stud bolts and tighten up the valve flange is in contact with the
actuator flange.
4) Tighten the nuts of the connecting stud bolts evenly with the
torque prescribed in the table. The stud bolts must be made of
ASTM A320 L7 steel, the nuts must be made of ASTM A194 grade
2 steel as minimum.
B) To assemble the actuator onto the valve by bracket with shell
joint, perform the following operations:

1) -Check that the coupling dimensions of the valve flange and stem, or of
the relevant extension, meet the actuator coupling dimensions (valve
stem and flange). Lubricate the valve stem with grease in order to make
the assembly easier
2) To make easier the assembly, the valve stem has to be in perfect
vertical position.

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3) -Disassemble the two halves of actuator pedestal shell joint (item 8) by

unscrewing the retaining screws (item 4 ),therefore disassemble the
valve stem joint (item 7).
4) -Lift the actuator by utilizing the proper lifting eyelets, and unscrew the
nuts and the stud bolts from the actuator pedestal.
5) -Assemble the actuator onto the valve, and arrange it in its correct
vertical position proper to connection between valve stem and actuator
cylinder rod.
6) -Screw the valve stem joint (item 7) on valve stem up to reach the proper
position which allow the reassembly of the two halves of shell joint (item
8), tighten the joint fastening screws (item 4).
7) -Screw the stud bolts (item 1) into the actuator pedestal flange, and
screw the nuts on the stud bolts.
8) -Tighten according to the nut (item 2) size torque requirements.

To operate refer to following table:

Table 1: nuts tightening torque

Tightening
Threading
torque (Nm)
M8 20
M10 40
M12 70
M14 110
M16 160
M20 320
M22 420
M24 550
M27 800
M30 1100
M33 1400
M36 1700

The screwing values in Table 1 were calculated considering the

materials ASTM A320 L7 for screws or tie rods and ASTM A194
gr.2H for the nuts.

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2.5 HYDRAULIC CONNECTIONS

Check that the values of hydraulic supply available are
compatible with those reported on the identification plate of the
actuator.
The connections should be made by qualified staff.
Use pipes and connections appropriate as for type, material and
dimensions.

Use motor fluid with purity degree ISO 4406 17/14 or NAS 1638
Class 8 (AS4059 Class 4B-F).
For special applications the lower contamination degree is
required. Please refer to the documentation supplied.

❑ Properly deburr the ends of rigid pipes

❑ Properly clean the interior of pipes sending through them plenty of
the supply fluid used in the system.
❑ Mould and fasten the connection pipes so that no irregular strains at
entries or loosening of threaded connections occur.
❑ Make the connections according to the operating diagram.
❑ Check the absence of leakages from hydraulic connections. If
necessary tighten the nuts of the pipe-fittings

2.6 ELECTRICAL CONNECTIONS (IF ANY)

Use components appropriate as for type, material and

dimensions
The connections should be made by qualified staff
Before carrying out any operation, cut line power off
Safety provisions as per CEI 64-8 regulation should be
complied with (same as IEC 60364).
Remove plastic plugs from cables entries
❑ Screw firmly the cable glands.

❑ Introduce connection cables.

❑ Make the connections in compliance with applicable wiring diagrams

on the documentation supplied.
❑ Screw the cable gland.

❑ Replace the plastic plugs of unused entries with metal plugs.

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2.7 COMMISSIONING

Installation, commissioning and maintenance and repair

works should be made by qualified staff.

Upon actuator commissioning please carry out the following checks:

❑ Check that paint is not be damaged during transport, if necessary

repair the damages to paint coat.

❑ Check that the values of hydraulic supply available in the system are
compatible with those reported on the identification plate of the
actuator (Figure 2) and on the documentation supplied.

❑ Check that the feed voltage values of the electric components

(solenoid valve coils, micro-switches, pressure switches, etc.) are
compatible with those reported on the identification plate of the
actuator (Figure 1).

❑ Check that the setting of the components of the actuator control unit
(pressure regulator, pressure switches, flow control valves, etc.)
meet the plant requirements.

❑ Carry out all kinds of operations and check their proper execution
(Sect. 3.3).

❑ Check the absence of leakages in the hydraulic connections.

If necessary tighten the nuts of the pipe-fittings

❑ Check proper operation of all the due signalling ( valve position,

hydraulic supply pressure etc. )

❑ Make a complete functional test in order to verify all the operations

are executed according to operating schematic diagram supplied.

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3 Operation and use

3.1 OPERATION DESCRIPTION

The supply fluid pressurizes the hydraulic-cylinder chamber relevant
to the operation to carry out (opening or closing) (see following
pages).
This pressure starts the linear motion of the piston and the
consequent motion of the valve stem that is coupled.
The spring action operate the valve stem in the opposite direction
(fail safe position)

Hydraulic
supply
connection

For local or remote operations, please refer to technical

documentation furnished with actuators.

The power and control systems are supplied on specific customer

demand.

For all the relevant information please refer to the specific

documentation supplied.

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Figure 4 – Single acting function with jackscrew

manual override MHP

3.2 RESIDUAL RISKS

The actuator has parts under pressure.

Use the due caution.
Use individual protections provided for by the laws and
provisions in force.

3.3 OPERATIONS
( refer to specific document: operating diagram furnished )

3.3.1 Emergency manual operation (MHP)

Refer to applicable control schematic in supplied

documentation.

The HLAS actuators can have an emergency manual override in

addition to the local and/or remote control system which controls the
oil supplied by a power pack for the “normal” actuator operation.
The emergency manual override mounted on the actuator, consists
of an hydraulic manual override and a hydraulic manual selector to
choose the actuator “Normal operation”, with oil supply from a power
pack, or the “Emergency manual operation”. For nominal pressure
until 105 bar the manual override is similar to chapter 7.2 table 3. For
nominal pressure upper to 105 bar the manual override will be OMFB
for carbon steel material, or dedicated model engineered by BIFFI for
stainless steel material
3.3.2 Remote control operations

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3.4 CALIBRATION OF THE ANGULAR STROKE

It is important that the mechanical stops of the actuator (and not
those of the valve) stop the linear stroke at both extreme valve
position (fully open and fully closed), except when this is required by
the valve operation).
The setting of the open/closed valve position (upward position)is
performed by adjusting the travel stop screw into the end flange of
the hydraulic cylinder and by the adjustment of the coupling of valve
stem to actuator joint for the downward position.

Picture 5 – Mechanical stop on cylinder end flange

For the adjustment of the mechanical stop on the end flange of

cylinder, follow these steps (Figure 6):

❑ Remove with the specific wrench (c1) the plug (t).

❑ Insert a wrench for Allen keys (c2) in the through hole until
reaching the adjustment pin (g).
❑ Keep the protection cover blocked with the special wrench (c3).
❑ If the actuator angular stroke is stopped before reaching the
upward position (fully open or closed), unscrew the adjusting
screw by turning it anticlockwise with a proper wrench , until the
valve reaches the right position
❑ If the actuator angular stroke is stopped beyond the upward
position (fully open or closed valve), screw the stop screw by
turning it clockwise until the valve reaches the right position.
❑ When the adjustment is over tighten the plug (t).

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HYDRAULIC WRENCH WRENCH WRENCH

CYLINDER C1 C2 C3
SIZE (mm) (mm) (mm)

075 22 10 36
100 22 10 36
135 22 10 36
175 22 14 46
200 27 14 46
235 27 17 65
280 27 17 65
300 36 17 110

Figure 6 – Mechanical stop of the cylinder

For high pressure cylinder models, the mechanical stop is internal
(without protection cover) proceed at the same way : (1) remove the
plug and (2) operate the adjusting screw

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3.5 CALIBRATION OF MICROSWITCHES (BIFFI LIMIT

SWITCH BOX ONLY)
Operate only the micro-switch corresponding to the
direction of operation being carried out, as clearly
reported on the micro-switch.
If different micro-switches assembly or limit switch box is
supplied, please refer to the specific documentation.
Micro-switches are placed inside a special box (Picture 7).
For micro-switches calibration please refer to the relative wiring
diagram and follow these steps:
❑ Unscrew the fastening screws of the cover (Picture 7).
❑ Remove the cover paying attention not to deteriorate the gasket
and the cylindrical and flat coupling surfaces.
❑ Operate the actuator (in opening or closing) with local hydraulic
operation (Section 3.3)
❑ Unscrew the screw of the operating cam relative to the micro-
switch to calibrate and adjust it according to the settings (Picture
8).
❑ Tighten the screw.
❑ Operate the actuator and adjust any other micro-switch with the
procedure already described.
❑ Position the cover making sure the cam-carrier shaft grips with
the index dragging shaft.
❑ Check that the cover and the index show the proper position of
the valve (Picture 9).
❑ Tighten the screws.

Picture 7 – Micro-switches Picture 8 – Cam adjustment

box

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If the index (Picture 9), does not signal the proper position of the
valve but is turned by 90°:
❑ Remove the roll pin placed on the position indicator (index).
❑ Turn the indicator until reaching its proper positioning.
❑ Put the roll pin back in its position.

End of stroke microswitches should be operated

before the stop of the stroke of the actuator due to
mechanical stops. Adjust the relative cams properly.

Position pin
indicator
(index)

Picture 9 – Position indicator and pin for

micro-switches box

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3.5 CALIBRATION OF THE OPERATION TIME

For actuator models with control system it’s possible regulate the
speed of actuator operations. The calibration of the operation time is
made by Biffi Italia S.r.L according to customer requirements and to
technical data-sheet included in technical documentation. If
necessary it’s possible to modify or reset the operating time through
two flow regulating valves (optional) placed on inlets of hydraulic
cylinder (refer to specific technical documentation furnished with
actuators scope of supply ).

Picture 10 – Adjustment of operating time by flow-regulator

valve (please refer to specific operating diagram, item 526,528
or 530)
To carry out the adjustment, operate the hand-wheel (turn clockwise
the hand-wheel to increase the operating time or turn the hand-wheel
counter-clockwise to decrease the operation time)

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4 Operational tests and inspections

Important: To ensure the guaranteed SIL grade, according to

IEC 61508, the functionality of actuator must be
checked with regular intervals of time, as described
in the Safety Manual

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5 Maintenance
Before carrying out any maintenance operation, it is
necessary to close the hydraulic feed line and exhaust
the pressure from the actuator cylinder and from the
control unit, to ensure safety of maintenance staff

Installation, commissioning and maintenance and

repair works should be carried out by qualified staff.

5.1 PERIODIC MAINTENANCE

HLAS actuators are designed to operate long-term in heavy-duty

operating conditions, without maintenance needs.

Periodicity and regularity of inspections is

particularly influenced by specific environmental and
working conditions.

They can be initially determined experimentally and

then be improved according to actual maintenance
conditions and needs.

Anyway every 2 years of operation the following is recommended:

❑ Check that the actuator operates the valve correctly and with the
required operating times. If the actuator operation is very infrequent,
carry out a few opening and closing operations with all the existing
controls (remote control, local control, emergency controls, etc.), if
this is allowed by the conditions of the plant.
❑ Check there are no hydraulic leakages. If necessary tighten the nuts
of the pipe-fittings.
❑ Check oil level (Pict. 11) into the hydraulic manual hand-pump, if
present (see chapt. 5.1.1)
❑ Check the actuators did not undergo accidental damage with oil
leakages found on site (Sect. 4.1.1).
❑ Check that improper closing of control-group cover did not produce
the presence of condensation on it.
❑ Check the integrity of worn out parts (gaskets, pads etc.).
❑ If there is an oil filter on the actuator, bleed the condense water
accumulated in the cup by opening the drain cock. Disassemble the
cup periodically and wash it with soap and water; disassemble the
filter: if this is made up of a sintered cartridge, wash it with nitrate

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solvent and blow through with oil. If the filter is made of cellulose, it
must be replaced when clogged.

Picture 11 – Level measuring stick

5.1.1 Check and restore oil level in the hydraulic manual

handpump ( refer to chapt. 7.2 table 4 )

During the actuator operation the oil tank has to be closed (not in
connection with the atmosphere). Then avoid cavitation it is
necessary to proceed as follows for the check of oil level into the
tank:
1) Unscrew the dipstick (1).
2) Move the actuator into open position.
3) Check that the oil level into the tank (4) is in correspondence of
the “MAX LEVEL” notch of the dipstick.
4) By leaving the dipstick unscrewed move the actuator, by the
pneumatic control or by the hand pump, to closed position.
5) Screw and tighten the dipstick.
If necessary substitute or added the oil, proceeding as follow:
❑ Remove the dipstick (1) from the tank cover (22).
❑ Unscrew the plug (27) and the washer (9) to drain all the oil.
❑ If some dirt or/and sludge is found in the oil drained from the tank,
before filling with new oil in the tank, disassemble the oil tank tube,
by unscrewing the two cap nuts (2), and clean the internal surfaces
of the tank. If necessary substitute the gaskets (21) of the tank.
❑ Replace the plug (27) and the washer (9) into the plate (11) and
tighten.
❑ Pour the new oil into the tank through the dipstick hole (1) on the
cover (22).
❑ Replace the dipstick (1).
❑ Add oil (Table 2) if in the tank the level is BELOW MINIMUM Picture
13).

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For refill use oil of the same brand as the one in the
tanks.
The cleanliness level for actuator without control-system is NAS
8 minimum. For actuator with control system the cleanliness
level is that required by singles components, in any case Biffi
Italia S.r.L respect the customer requirements to scope of
supply, for applicable cleanliness level, refer to document:
technical data-sheet for actuators

Table 2:features of hydraulic oil suggested by BIFFI Italia S.r.l for refilling
in different working condition:
Standard temperature conditions (-30°C/+85°):
Producer AGIP
Name ARNICA 22
Viscosity at 40° C 20.9 mm²/s
Viscosity at 100° C 4.73 mm²/s
Viscosity index ASTM 153
Flash point 192° C
Pour point -42° C
Specific weight (at 15°C) 0,857 Kg/l

Equivalent oils: SHELL TELLUS PLUS 22

CHEVRON HYDRAULIC OIL AW ISO 22
MOBIL DTE22
EXXON UNIVIS N22
EQUIVIS ZS22
BP ENERGOL HLP-HM22
CASTROL DYSPIN AWS22

Low temperature conditions (until -46°C):

Manufactured SHELL
Name AEROSHELL
FLUID 41
Viscosity at -54° C 2300 cST
Viscosity at -40° C 491 cST
Viscosity at 40° C 14,1 cST
Viscosity at 100° C 5,30 cST
Viscosity index (ISO 2909) >200
Flash point 105° C
Pour point <-60° C
Specific weight 0,87 Kg/dm3
(or equivalent)

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Low temperature conditions (until -60°C):

Manufactured SYNTESIS
Name SYNTRASS-CS
500
Viscosity at -60° C 580 cST
Viscosity at -30° C 39cST
Viscosity at 20° C 5,8 cST
Viscosity at 50° C 2,1 cST
Flash point 152° C
Pour point -68° C
Specific weight 0,897 Kg/dm3
(or equivalent)

5.2 EXTRAORDINARY MAINTENANCE

In case of need extraordinary maintenance can be performed on the
parts of the actuator.

Anyway contact BIFFI ITALIA customer care.

5.2.1 Lubrication of mechanism

For normal duty the HLAS actuator is lubricated "for life". In case of
high load and high and high frequency of operation it may be
necessary to periodically restore the lubrication: it is advisable to
apply a generous coating of grease on the contact surfaces of
moving parts. For this operation is necessary to disassemble the
closing plates (item 41 refer to table pag.34) from pedestal with
coupling-joint.

The following grease is used by BIFFI for standard working

temperature and suggested for re-lubrication:

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AGIP MU/EP/2 AEROSHELL GREASE 7 or

equivalent
To be used in standard temperature To be used in low temperature
conditions (-30°C/+85°C) conditions
(-60°C/+65°C)
NLGI consistency: 2
Worked penetration: 280 dmm Colour: Buff
ASTM Dropping Point: 185°C Physical state: Semi-solid at
ambient temperature
Base oil viscosity at 40°C: 160 mm²/s
Odour : Slight
ISO Classification: L-X-BCHB 2
Density : 966 Kg/m³ at 15°C
DIN 51 825: KP2K – 20
Flash Point : ›215°C (COC)(Based
on synthetic oil)
Equivalent to: ESSO BEACON EP2 Dropping point : 260°C (ASTM D-
BP GREASE LTX2 566)
SHELL ALVANIA GREASE R2 Product code : 001A0065
ARAL ARALUB HL2 Infosafe No.: ACISO GB/eng/C
CHEVRON DURALITH GREASE EP2
CHEVRON SPHEEROL AP2
TEXACO MULTIFAK EP2
MOBILPLEX 47
PETROMIN GREASE EP2

If there are leaks in the hydraulic cylinder, or a malfunction in the

mechanical components, or in case of scheduled preventive
maintenance, the actuator must be disassembled and seals must be
replaced with reference to the follow general sectional drawing and
adopting the following procedures:

5.2.2 Replacement of cylinder seals (refer to table on pag. 31)

Before carrying out any maintenance operation, it is necessary to

close the hydraulic feed line and exhaust the pressure from the
actuator cylinder and from the control unit, to ensure safety of
maintenance staff.
If the actuator can be operated, it is essential to take it to fail safe
position, with the spring totally extended.

1) Unscrew the adjusting screw cover (for low pressure cylinder) or

the protection plug (13) (for high pressure cylinder) from the
cylinder end flange.

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2) Measure the distance of the stop screw (10) with reference to the
end flange surface (12), so as to be able to easily restore the
setting of the actuator mechanical stop, once the maintenance
procedures have been completed.
3) Unscrew the stop screw (10) by turning it anticlockwise with an
Allen wrench until the screw is complete with drawn inside the end
flange threaded hole.
4) Unscrew the nuts (14) from the tie rods (9): they must be gradually
unscrewed all at the same time.
5) Slide off the end flange (12) and the tube (11).
6) If the actuator control unit requires the cylinder chamber head
flange side to be also filled with oil, and the piston rod seal ring (3)
to be replaced, remove the flange (1). Unscrew the piston rod
threaded end from the adaptor bush. Slide off the piston rod from
the head flange (5).
7) Disassemble the head flange.

Seals replacement

Prior to reassembly check that the actuator components are in good

conditions and clean. Lubricate all the surfaces of the parts, which
move in contact with other components, by a recommended grease.
If the O-ring must be replaced, remove the existing one from its
groove, clean the groove carefully and lubricate it with a protective oil
or grease film. Assemble the new O-ring into its groove and lubricate
it with a protective oil or grease film.
1) Replace the O-ring (2) of the head flange (1).
2) Replace the back-up-ring (4) of the head flange (1).
To replace the piston rod seal rings (3) proceed as follows :
1) Remove the existing Teflon seal ring (3) with its O-ring from their
groove.
2) Clean the groove carefully and lubricate it with a protective oil or
grease film.
3) Assemble the new O-ring into its groove and lubricate it with a
protective oil or grease film.
4) Assemble the new Teflon seal ring (3) into the flange groove,
inside its rubber
O-ring, by bending it : take care that the bending radius is as large
as possible to avoid damaged the seal. Then enlarge the seal ring
with your fingers so as to restore its round shape: pay attention not
to utilise any tools which can damage the seal ring.
To replace the piston seal ring (8) proceed as follows :

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1) Remove the existing Teflon seal ring (8) with its O-ring from their
groove.
2) Clean the groove carefully and lubricate it with a protective oil or
grease film.
3) Assemble the new O-ring into its groove and lubricate it with a
protective oil or grease film.
4) Assemble the new Teflon seal ring (8) on its rubber O-ring by
introducing one side of it into the groove, then enlarge it with your
fingers so as to fit it into the groove: take care to enlarge it
uniformly without any tools which could possibly damage it. The
elastic memory of the kind of Teflon the seal ring is made of allows
the ring to shrink back to its previous dimension after a short time.

Reassembly :

1) Assemble the head flange (1), replace the washers if damaged.

2) Lubricate the piston rod (24) surface, with a protective oil or
grease film and introduce it into the head flange hole, taking care
not to damage the O-ring (3). Carefully clean the threaded end of
the piston rod (24) and the threaded hole of the adaptor. Spread
some sealant LOCTITE 452, or equivalent, on the rod threaded
end and tighten.
3) Carefully clean the inside of the tube (11) and check that the entire
surface, particular that of the bevels, is not damaged. Lubricate
with a protective oil or grease film the tube internal surface and the
bevels at the ends. Slide the tube onto the piston taking care not
to damaged the Teflon seal ring (8): the tube bevel has to
smoothly compress the seal ring; take care also not to damage the
head flange O-ring (2).
4) Assemble the end flange by centring it on the inside diameter of
the tube, taking care not to damage the O-ring (2).
5) Assemble the nuts (14) onto the tie rods (9). Tighten the nuts to
the recommended torque, alternating between opposite corners.
6) Screw the stop screw (10) by turning it clockwise with an Allen
wrench until it reaches its original position (the same distance with
reference to the end flange surface).
7) Replace the O-ring (15)under the protection cover
8) Screw the protection cover (13) into the cylinder end flange.

Carry out a few operations (Sect. 3) to check there are

no leakages from the gaskets.

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SINGLE ACTING-SPRING RETURN HYDRAULIC

LINEAR ACTUATOR - SECTIONAL DRAWING

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5.3 DISMANTLING AND DEMOLITION

Before starting the disassembly a large area should be created

around the actuator so to allow any kind of movement without
problems of further risks created by work-site.
Before disassembling the actuator it is necessary to close the
pneumatic feed line and discharge pressure from the cylinder of
the actuator, from the control unit and from the accumulator
tank, if present.
If actuator is still mounted onto the valve, loosen the threaded
connections between valve and actuator (screws, tie rods, nuts)
Lift the actuator using the proper lifting points (see chapter 2.2).
If the actuator needs storage, before demolition, see chapter 2.3.
The demolition of the actuator both concerning any electrical
and mechanical parts should be made by specialized staff
Separate the parts composing the actuator according to their nature
(ex. metallic, and plastic materials, fluids etc.) and send them to
differentiated waste collection sites, as provided for by the laws and
provisions in force.

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6 Troubleshooting
6.1 FAILURE OR BREAKDOWN RESEARCH
Event Possible cause Remedy
Actuator does not
work
Lack of hydraulic Open line stop valve
supply
Blocked valve Repair or replace
Wrong position of the Restore correct
distributor of the position
hydraulic manual
override
Failure of the spring Call BIFFI Italia S.r.l.
Customer Service
Failure of the control Call BIFFI Italia S.r.l.
system Customer Service
Clogged filter Clean or replace the
cartridge.
Actuator too slow Low supply pressure Restore (Sect. 1.4)
Wrong calibration of Restore (Sect. 3.6)
flow regulator valves
Wear of the valve Replace
Actuator too fast High supply pressure Restore (Sect. 1.4)
Wrong calibration of Restore (Sect. 3.6)
flow regulator valves
Leakages on Deterioration and/or Call BIFFI Italia S.r.l.
hydraulic or damage to gaskets Customer Service.
pneumatic circuits
Incorrect position of Wrong adjustment of Restore (Sect. 3.4)
the valve mechanical stops
Wrong warning of Restore (Sect. 3.5)
microswitches
Hydraulic manual handle positioned on Position the handle on
pump does not work remote control the indication of the
operation to make
Leakages on the check Call BIFFI Italia S.r.l.
valve of the hydraulic Customer Service
control group
Incorrect position of Wrong adjustment of Reset (Par. 3.4)
the valve mechanical stops
Wrong warning of Reset (Par. 3.5)
micro-switches

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7 Layouts
7.1 SPARE PARTS ORDER
For spare parts order to the relevant BIFFI office please make
reference to BIFFI order confirmation concerning all the supply, and
serial number of the actuator (Sect. 1.2) for any specific spare part
for a specific actuator model.
Please send every spare-parts request to :

BIFFI ITALIA s.r.l. - Servizio Assistenza Tecnica Clienti

Tel. : 0523-944523__________

Fax: 0523-941885__ e-mail: spareservice@biffi.it________

please specify :
1. actuator model;
2. BIFFI acknowledgement ;
3. spare parts code;
4. quantity;
5. transport condition;
6. involved people.

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7.2 PARTS-LIST FOR MAINTENANCE AND REPLACING

PROCEDURE
Table 1: Pedestal with coupling joint

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Table 2: Spring cartridge

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Table 3: hydraulic cylinder

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Table 4: Hydraulic control unit MHP

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8 Date report for maintenance

operations

Last maintenance operation date : ( in factory, on delivery ): …..

……… exec. by : …………

……… exec. by : …………
……… exec. by : …………

Next maintenance operation date: ……… exec. by : …………

……… exec. by : …………
……… exec. by : …………

Start-up date : ( in factory, on delivery ).…………………….

( on plant ) .…………………….

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