Specifications
Heavy-Duty Hydraulic Cylinders
HV2 Series
Catalog HY08-M1140-3/NA
74
www.milleruidpower.com
Miller Fluid Power
Des Plaines, IL
Milton, Ontario Canada
Before selecting or using Miller Fluid Power (The Company) cylinders or related
accessories, it is important that you read, understand and follow the following
safety information. Training is advised before selecting and using The Company’s
products.
1
.0 General Instructions
1.1 Scope – This safety guide provides instructions for selecting and using
(including assembling, installing, and maintaining) cylinder products. This
safety guide is a supplement to and is to be used with the specic Company
publications for the specic cylinder products that are being considered for
use.
1
.2 Fail Safe – Cylinder products can and do fail without warning for many
reasons. All systems and equipment should be designed in a fail-safe mode
so that if the failure of a cylinder product occurs people and property won’t be
endangered.
1
.3 Distribution – Provide a free copy of this safety guide to each person
responsible for selecting or using cylinder products. Do not select or use
The Company’s cylinders without thoroughly reading and understanding this
safety guide as well as the specic Company publications for the products
considered or selected.
1
.4 User Responsibility – Due to very wide variety of cylinder applications
and cylinder operating conditions, The Company does not warrant that any
particular cylinder is suitable for any specic application. This safety guide
does not analyze all technical parameters that must be considered in select-
ing a product. The hydraulic and pneumatic cylinders outlined in this catalog
are designed to The Company’s design guidelines and do not necessarily
meet the design guideline of other agencies such as American Bureau of
Shipping, ASME Pressure Vessel Code etc. The user, through its own
analysis and testing, is solely responsible for:
• M
aking the nal selection of the cylinders and related accessories.
• Determining if the cylinders are required to meet specic design require-
ments as required by the Agency(s) or industry standards covering the
design of the user’s equipment.
•
Assuring that the user’s requirements are met, OSHA requirements are
met, and safety guidelines from the applicable agencies such as but not
limited to ANSI are followed and that the use presents no health or safety
hazards.
•
Providing all appropriate health and safety warnings on the equipment on
which the cylinders are used.
1
.5 Additional Questions – Call the appropriate Company technical service
department if you have any questions or require any additional information.
See the Company publication for the product being considered or used, or
call the number on the back page of this catalog for the technical service
department.
2
.0 Cylinder and Accessories Selection
2.1 Seals
– Part of the process of selecting a cylinder is the selection of
seal compounds. Before making this selection, consult the “seal information
page(s)” of the publication for the series of cylinders of interest.
T
he application of cylinders may allow uids such as cutting uids, wash
down uids etc. to come in contact with the external area of the cylinder.
These uids may attack the piston rod wiper and or the primary seal and
must be taken into account when selecting and specifying seal compounds.
D
ynamic seals will wear. The rate of wear will depend on many operating
factors. Wear can be rapid if a cylinder is mis-aligned or if the cylinder has
been improperly serviced. The user must take seal wear into consideration
in the application of cylinders.
2
.2 Piston Rods – Possible consequences of piston rod failure or
separation of the piston rod from the piston include, but are not limited to are:
• Piston rod and or attached load thrown o at high speed.
• High velocity uid discharge.
• Piston rod extending when pressure is applied in the piston
retract mode.
P
iston rods or machine members attached to the piston rod may move
suddenly and without warning as a consequence of other conditions
occurring to the machine such as, but not limited to:
•
Unexpected detachment of the machine member from the piston rod.
• Failure of the pressurized uid delivery system (hoses, ttings, valves,
pumps, compressors) which maintain cylinder position.
•
Catastrophic cylinder seal failure leading to sudden loss of pressurized
uid.
•
Failure of the machine control system.
Follow the recommendations of the “Piston Rod Selection Chart and Data”
in the publication for the series of cylinders of interest. The suggested piston
rod diameter in these charts must be followed in order to avoid piston rod
buckling.
P
iston rods are not normally designed to absorb bending moments or loads
which are perpendicular to the axis of piston rod motion. These additional
loads can cause the piston rod to fail. If these types of additional loads are
expected to be imposed on the piston rod, their magnitude should be made
known to our engineering department.
T
he cylinder user should always make sure that the piston rod is securely
attached to the machine member.
O
n occasion cylinders are ordered with double rods (a piston rod extended
from both ends of the cylinder). In some cases a stop is threaded on to one
of the piston rods and used as an external stroke adjuster. On occasions
spacers are attached to the machine member connected to the piston rod
and also used as a stroke adjuster. In both cases the stops will create a pinch
point and the user should consider appropriate use of guards. If these
external stops are not perpendicular to the mating contact surface, or if debris
is trapped between the contact surfaces, a bending moment will be placed
on the piston rod, which can lead to piston rod failure. An external stop will
also negate the eect of cushioning and will subject the piston rod to impact
loading. Those two (2) conditions can cause piston rod failure. Internal stroke
adjusters are available with and without cushions. The use of external stroke
adjusters should be reviewed with our engineering department.
T
he piston rod to piston and the stud to piston rod threaded connections are
secured with an anaerobic adhesive. The strength of the adhesive decreases
with increasing temperature. Cylinders which can be exposed to tempera-
tures above +250°F (+121°C) are to be ordered with a non studded piston
rod and a pinned piston to rod joint.
2
.3 Cushions – Cushions should be considered for cylinder applications
when the piston velocity is expected to be over 4 inches/second.
Cylinder cushions are normally designed to absorb the energy of a linear
applied load. A rotating mass has considerably more energy than the same
mass moving in a linear mode. Cushioning for a rotating mass application
should be review by our engineering department.
2
.4 Cylinder Mountings – Some cylinder mounting congurations may have
certain limitations such as but not limited to minimum stroke for side or foot
mounting cylinders or pressure de-ratings for certain mounts. Carefully review
the catalog for these types of restrictions.
A
lways mount cylinders using the largest possible high tensile alloy steel
socket head cap screws that can t in the cylinder mounting holes and torque
them to the manufacturer’s recommendations for their size.
2.5 Port Fittings – Hydraulic cylinders applied with meter out or decelera-
tion circuits are subject to intensied pressure at piston rod end.
The rod end pressure is approximately equal to:
operating pressure x eective cap end area
eective rod end piston area
Contact your connector supplier for the pressure rating of individual
connectors.
3
.0 Cylinder and Accessories Installation and Mounting
3.1 Installation
3
.1.1 – Cleanliness is an important consideration, and cylinders are
shipped with the ports plugged to protect them from contaminants enter-
ing the ports. These plugs should not be removed until the piping is to
be installed. Before making the connection to the cylinder ports, piping
should be thoroughly cleaned to remove all chips or burrs which might
have resulted from threading or aring operations.
Safety Guide for Selecting and Using Hydraulic, Pneumatic Cylinders and Their Accessories
WARNING: FAILURE OF THE CYLINDER, ITS PARTS, ITS MOUNTING, ITS CONNECTIONS TO OTHER OBJECTS,
OR ITS CONTROLS CAN RESULT IN:
• Unanticipated or uncontrolled movement of the cylinder or objects connected to it.
• Falling of the cylinder or objects held up by it.
• Fluid escaping from the cylinder, potentially at high velocity.
THESE EVENTS COULD CAUSE DEATH OR PERSONAL INJURY BY, FOR EXAMPLE, PERSONS FALLING FROM
H
IGH LOCATIONS, BEING CRUSHED OR STRUCK BY HEAVY OR FAST MOVING OBJECTS, BEING PUSHED INTO
DANGEROUS EQUIPMENT OR SITUATIONS, OR SLIPPING ON ESCAPED FLUID.
!
Cylinder Safety Guide