Emerson Bettis GVO-C Series User manual

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0
March 2016
Bettis GVO-C Series
GVO-CHP-DA Hydraulic Actuators

I
Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0
Table of Contents
March 2016
Table of Contents
Table of Contents
Section 1: Introduction ��������������������������������������������������������1
Section 2: Operation ������������������������������������������������������������2
Section 3: Maintenance
3.1 Checking the Gland Packing and Barrel Seals .............................................. 3
3.2 Checking the Piston Packing ....................................................................... 3
Section 4: Packing Replacement
4.1 Dismantling the Cylinder ............................................................................ 4
4.2 Reassembling the Cylinder .......................................................................... 5
Section 5: Packing-Kit Selection �������������������������������������������7
Section 6: Storage Condition ������������������������������������������������8

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0
March 2016
1
Section 1: Introduction
Introduction
Section 1: Introduction
Bettis GVO-C Linear cylinder has been engineered and manufactured to meet or exceed
the most varied applications.
It has been factory inspected, adjusted and tested to pre-determined tolerances and
specifications to ensure trouble free operation.

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0 March 2016
2
Section 2: Operation
Operation
Section 2: Operation
1. Only filtered hydraulic oil ESSO NUTO-H32 or equivalent should be used to
actuate cylinder. The oil must be filtered to remove all contaminants.
2. Care should be exercised to ensure that regulated oil pressure does not
exceed the indicated pressure rating.
3. Unless supplied with optional metallic rod-scraper and rod boot, the cylinder
should be operated in a low dust and abrasive free environment for maximum
life.
4. The standard operating temperature is between –30°C and +120°C
(–25°F and +250°F). Consult the factory for extreme temperature applications.
For Special Application, please consult technical staff or your nearest distributor.

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0
March 2016
3
Section 3: Maintenance
Maintenance
Section 3: Maintenance
Bettis GVO-C Linear cylinder has been designed for a long life expectancy, with the
exception of the piston packings and gland packings, which should be replaced
periodically, depending on environmental conditions and frequency of operation.
NOTE:
This product is only intended for use in large-scale fixed installations excluded from the
scope of Directive 2011/65/EU on the restriction of the use of certain hazardous
substances in electrical and electronic equipment (RoHS 2).
3�1 Checking the Gland Packing and Barrel Seals
1. Connect pressure at the rod end port.
2. Verify the gland bushing to observe any abnormal oil accumulation in this zone.
3. Verify the zone between head and barrel.
4. Connect pressure at the cap end port.
5. Verify the zone between cap and barrel.
3�2 Checking the Piston Packing
1. Connect pressure at the cap end port to allow cylinder to fully extend the piston
rod.
2. Install a pressure gauge at the rod end port and read it during a lead of time of
30 seconds. If the pressure gauge reads 0 PSI, that means there is no leak.
If the pressure rises, the packing should be changed.
3. Connect pressure at the rod end port and the gauge to the cap end port and
repeat the same steps to verify the piston packing in the opposite direction.

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0 March 2016
4
Section 4: Packing Replacement
Packing Replacement
Section 4: Packing Replacement
4�1 Dismantling the Cylinder
1. Remove the cylinder from machine to which it is mounted.
2. Place the cylinder in a clean work area.
3. Unscrew tie rod nuts and remove the tie rods. Always use appropriate tools.
NOTE:
There are two set screws that retain the tie rods to the head that must be loosened.
4. Remove the head and the cap from barrel. Use a rubber mallet if necessary.
5. Pull out the piston and piston rod assembly from barrel. Take care not to damage
the rod and the barrel. Do Not Disassemble the Rod from the Piston.
6. Remove gland retainer.
7. Remove packings from both piston and gland bushing, noting orientation of
packing lips (vees). Packing must face pressure. Remove seals (O-rings) from
head and cap grooves.
8. Verify inside of barrel, gland bushing and rod surface for damage and/or excessive
wear.

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0
March 2016
5
Section 4: Packing Replacement
Packing Replacement
4�2 Reassembling the Cylinder
1. Clean carefully all parts, grooves and surfaces prior to starting the assembly.
Use compressed air to remove all solid particles.
2. Apply a light coat of grease (ESSO LIDOK EP2 or equivalent) to all packings and
seal grooves.
3. Place the O-rings in the head and cap grooves.
4. Install the piston packing. Vees must face pressure.
5. Install the wear band on piston (if any).
6. Slide the piston and piston rod assembly into the barrel. Take care not to
damage the packing.
7. Carefully install gland seal, gland packing, back-ups and rod wiper on the
gland bushing.
8. Insert the gland bushing into the head. Use a rubber hammer if necessary.
9. Install gland retainer.
10. Install the cap on the barrel. Check if the barrel seal (O-ring) is in the groove.
11. Slide the cap over the piston rod, being sure not to damage the bushing packing
and barrel seal remains in place. Install the head on the barrel.
12. Install tie rods and nuts. Verify head and cap alignment.
13. Tighten tie rod nuts using a sequential method (1, 2, 3 and 4. See Figure 1).
Torque applied: See Table 1.

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0 March 2016
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Section 4: Packing Replacement
Packing Replacement
Figure 1 Tie Rod Nut Torquing Sequence
Table 1� Torque Values
Cylinder Bore
(Inches)
Number of
Tie Rods
Diameter of
Tie Rods (Inches)
Torque
(lb-ft)
1-1/2 4 3/8 25
24 1/2 63
2-1/2 4 1/2 63
3-1/4 4 5/8 168
44 5/8 184
54 7/8 437
64 1 740
74 1-1/8 890
84 1-1/4 1200

Operation and Maintenance Manual
GVO-CHP-DA.IOM.1001 Rev. 0
March 2016
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Section 5: Packing-Kit Selection
Packing-Kit Selection
Section 5: Packing-Kit Selection
Always use genuine Bettis GVO-C Linear parts to ensure proper fit and function for
continuous trouble free operation.
In order to purchase the right repair kit for your cylinder, you must give us the part
number and the serial number shown on the identification tag of the cylinder located
on the barrel.
For more technical information, please consult our brochure or call us.