SIGMA projetor - Manual (Page 38)

MAINTENANCE INSTRUCTIONS
4.7
Model 880 Series Annual Maintenance Requirements
Model 880 Series exposure devices must receive inspection and maintenance at least once a year.
The locking mechanism and outlet port mechanism must be removed from the exposure device and
disassembled for proper cleaning, inspection and lubrication of components that are critical to safety.
These procedures can only be performed on an empty exposure device, which requires transfer of the
radioactive source assembly into an approved storage container.
The inspection and maintenance procedures must be performed by personnel specifically trained and
qualified for this work. QSA Global, Inc. service engineers will service these systems at one of their
service centers or in the field upon request.
Trained and qualified personnel who wish to perform this work should use the following procedure:
1
Perform a daily inspection of the system and transfer the radioactive source assembly into an
approved storage container. Disengage remote controls and source guide tubes. The exposure
device must be empty for the following steps.
2
Remove the four 5/16-18 x 1½ in socket button-head screws that retain the locking mechanism plate
from the empty Model 880 device using the tamperproof tool bit mounted in a ratchet.
3 Remove the 10-32 socket head screws that retain the selector-ring and plunger lock housings from
the mounting plate using a 5/32 in Allen wrench.
4
Disassemble the locking mechanism assembly, taking care not to lose the spring loaded parts. Place
the disassembled locking mechanism components into a pan filled with fresh, clean solvent. Clean all
parts using a brush to dislodge any dirt or grease. Remove cleaned parts from the solvent bath, dry
and place on a clean surface. Inspect all parts for wear. Replace worn parts as necessary.
Discard all used locking mechanism springs and replace with new springs. All compression springs
located within the selector ring mechanism must be replaced at 12-month intervals to ensure smooth
and consistent operation of the mechanism.
When ordering spare parts, quote the model and serial number of the exposure device as well as the
part number to ensure correct replacement.
Remove the lock retainer from the mounting plate by unscrewing the two 10-32 x ½ in socket head
screws using a 5/32 in Allen wrench. Remove the plunger lock from the lock retainer by removing the
cap screw using a 3/32 in Allen wrench. Clean the lock plunger, lock retainer and springs in a solvent
bath. Ensure the lock plunger is thoroughly rinsed to remove all dust from the key tumblers. Remove
the cleaned parts from the solvent bath and dry thoroughly, using compressed air to dry the lock
tumbler. Inspect all parts for wear. Replace worn parts as necessary. Lubricate the plunger lock
barrel and tumbler using two drops of a light viscosity oil. Apply Vibratite™ thread sealant to the lock
set screw and install. Check the plunger lock for proper function by using the key to engage and
unlock. Apply Vibratite™ to the lock retainer's 10-32 x ½ in screws, then mount the lock retainer to
the locking mechanism plate. Hand-tighten the screws using a 5/32 in Allen wrench.
Apply a light coating of lubrication to the inside surfaces of the selector body and selector ring using
MIL-G-23827B (or C), MIL-PRF-23827C, (or equivalent radiation resistant grease authorized by QSA
Global, Inc.). Do not lubricate the lock slide and sleeve. Note that some types of greases may
undergo chemical changes and form tars when exposed to radiation.