9 - AHP Merkle GmbH

4 Operating and maintenance instructions
4.1 General instructions for maintenance of hydraulic cylinders
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As a general rule, the same general requirements concerning maintenance work apply for hydraulic cylinders
as for other machine components. Maintenance work should be performed only by trained, qualifi ed personnel.
To prevent damage to the seals and cylinder parts, it is important to always pay attention to cleanness.
When changing seals, there are some important points that must be observed. Scratches, scoring and notches
damage seals and reduce their service life. Therefore is also important during maintenance work to make sure
not to scratch surfaces or edges, and not to damage the cylinder or seals with impact effects. For safe installation
of seals there are corresponding installation sets that can be purchased directly from AHP Merkle.
For some cylinders with inductive proximity switches, the switches have to be removed before dismantling.
Furthermore, there are some essential points that must be observed not only for maintenance work, but also
for storage. These include the type of storage and the creation of certain storage conditions on the cylinder,
seals and add-on parts, such as degreasing and protection against light, moisture, heat, etc.
It must also be ensured that seals are not stored in the vicinity of adhesives, solvents, fuels, chemicals, acids,
disinfectants, or the like. See also DIN 7716 „Rubber products; requirements for storage, cleaning and
maintenance“.
Seals CANNOT be stored for indefi nite periods.
Heat and light additionally speed up material
changes.
Complete installation sets for seals can be purchased
directly from AHP Merkle
www.ahp.de
E-Mail: service@ahp.de
Tel.: +49 76 65 42 08-0
Fax: +49 76 65 42 08-88
4.2 Procedure for assembly and maintenance work
As a fundamental rule, only qualifi ed personnel may perform work on hydraulic cylinders. At the beginning
of maintenance work on hydraulic cylinders it must be ensured that no load motions are possible when
the hydraulic system is depressurized. Suitable measures must be taken to ensure this, and the work safety
rules must be observed. When installing or removing the hydraulic cylinder, the instructions of the machine
manu facturer and/or systems integrator must be observed.
The use of system-based safety systems such as check valves or the like is not suffi cient by itself.
Before the cylinder is opened or screw or hose connections are detached, it must be ensured that the entire
hydraulic system has been depressurized – and also that it is not possible for pressure to build up unintentionally.
All of the lines connected to the cylinder have to be removed before the fastening is released. It must be
ensured that releasing the fastening will not endanger the maintenance personnel or any other persons.
It is advisable to ensure that no large quantities of oil can escape when the
hydraulic system is opened at the cylinder. It may be possible to do this using
shut off valves or quick disconnects within the hydraulic system, which can be
used to cut off large volumes of oil from the rest of the system.