Handling - Leser 411 Instructions De Service

3. Loosen and remove the lever cover (40.1).
4. Loosen the spindle cap (40.12) from the spindle
(12), remove the securing ring (40.14) and the
pin (40.13).
5. Loosen the lock nut (19) of the adjusting screw
(18).
1)
6. Turn the adjusting screw (18) anticlockwise to
remove all spring tension.
7. Remove the hex. nuts (56) from the flange of the
bonnet (9).
8. Lift off the bonnet (9).
9. Remove the upper spring plate (16).
10. Lift off the spring (54) and remove lower spring
plate (16) and split rings (14).
11. Remove spindle (12) with guide (8) and disc (7).
12. Carefully clean seat (5) and disc (7), and if
required body internals.
13. Refit spindle (12) with guide (8) and disc (7).
14. Fit the split rings (14) into spindle groove and
retain with the securing ring (59); slip on lower
spring plate (16) to locate on split rings (14).
15. Replace spring (54).
16. Slip on the upper spring plate (16) onto the
spindle (12).
17. Align adjusting screw (18), and bonnet (9). over
the spindle (12) and refit.
18. Fit and tighten the hex. nuts (56).
1)
19. Load the spring (54) to obtain the required set
pressure. Clockwise rotation of adjusting screw
(18) increases pressure. Anticlockwise rotation
of adjusting screw (18) reduces pressure.
20. Tighten the lock nut (19) onto the adjusting
screw (18).
21. Refit and secure spindle cap (40.12) by pin
(40.13) and securing ring (40.14).
22. Screw-on the lever cover (40.1).
23. Pull the lever (40.6) towards the middle so that
the lifting fork (40.5) is pushed under the spindle
cap (40.12).
24. Test spindle will lift correctly by pulling lever.
These instructions are applicable for relief
valves, safety valves and safety relief valves.
1) Caution: During all work the spindle has to be
secured against twisting in order to prevent
damage to the sealing surfaces.
The following points should be noted:
The pressure setting is wire-locked and sealed
against unauthorized alteration. The rules of the
TÜV, agreed by the manufacturer, require the
fitting of a type test approval plate stating the
correct valve data. The manufacturer cannot be
held responsible for any changes to set
pressure or other alterations after despatch
from the factory. Necessary modifications
should only be made by authorised distributors
of LESER or under the supervision of the TÜV
or any other competent inspection authority.

14 Handling

There is a risk of injury from sharp edges and
burrs. For this reason all parts have to be
handled with caution.
There is a risk from safety valves falling over.
They always have to be secured adequately.
During dismantling the spring must not be
tensioned. Otherwise there is danger of injury
from flying parts. Observe the assembly
instructions for the relevant safety valves!
Before dismantling you should always check
whether there is, or could be, any medium in
the bonnet; also check what the medium is.
There is a great risk of injury, chemical
burns or poisoning if there is any remaining
medium inside the safety valve.
One should use conventional high quality tools
in order to minimise the risks arising from bad
quality tools or inadequate tools. Any necessary
special tools are indicated in the assembly
instructions.
Safety valves may only be dismantled and
assembled by skilled staff.
The training can be carried out:
•
In the workshop by experienced staff
•
At LESER training seminars
•
By means of LESER documentation, e.g.,
videos, operating instructions, catalogues,
assembly instructions
The maintenance staff must be informed about
the risks during dismantling and installing the
safety valves.
Contamination and damage to the safety valve
must be avoided. Suitable cartons, protective
covers for the flanges, wrapping foil, shipping
palettes etc. have to be used. The packaging
must be completely removed before installation
as otherwise the function of the safety valve
cannot be guaranteed.
Safety valves have to be handled with care as
otherwise the vulnerable sealing surfaces can
be damaged or the safety valve might even be
rendered useless.
Safety valves must be stored in a dry place.
The optimum storage temperature is 5 °C to
40 °C. For o-ring discs temperatures below
freezing should be avoided, if possible. The
temperature resistance, in particular of the
o-ring materials, has to be taken into account.
Upper limit for storage: 50 °C
Lower limit for storage: -10 °C
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