Husky 521-0 User Manual
Ultra 500/750/1000 Single Cavity Valve Gate 2.0
Service Procedure: 521-0
.
Product Affected Reference
Molds
Revision History
Rev. No. Comments Date
0 Initial release 2006-April-28
©2006 Husky Injection Molding Systems Ltd.
This document is the property of Husky Injection Molding Systems Ltd.
and the information herein is strictly confidential. This document shall
not be reproduced or used without the written permission of Husky
Injection Molding Systems Ltd.
Keeping our customers in the lead
Summary: Follow this procedure to:
- perform preventative maintenance
- disassemble the Single Cavity Valve Gate (SCVG) unit
- replace the valve stem
- replace the seals
- reassemble the SCVG unit
Estimated Hours: 2 hours
Special Tools Required:
Reverse taper stem removal tool (HPN: 3512615).
Parts List:
HPN Description Qty
644751
534526 High temperature grease
High temperature anti-seize compound
*
1
1
1. Perform Lockout/Tagout. Refer to Machine Manual
for details.
WARNING!
Complete Lockout/Tagout of all energy
sources in accordance with applicable
local codes before performing
maintenance activities. Failure to do so
can result in injury or death.
*Estimated hours are for planning purposes only and do not include preparation times.
Service Procedure 521-0 2 of 21
Weepage
Every 250,000 cycles the SCVG unit should be
disassembled, any weepage in the stem retainer well
should be cleaned out, and all seals replaced (see Seal
Replacement).
NOTE: Refer to the section entitled "Disassembly" for
instructions on how to disassemble the SCVG
Disassembly
1. Remove the Locating Ring (not shown).
unit.
NOTE: Jacking screws are provided if necessary.
2. Make sure the wires and air lines are free and clear of
the unit.
3. Pull the unit from the mold.
4. Remove the flexible air lines and air fittings
(Figure 1, item 20).
5. Loosen the four SHCS (item 13) securing the sprue
bushing insert (item 32) and remove them from the
extruder pad (item 31).
6. Loosen the four SHCS (item 14) securing the
extruder pad (item 31) and remove them from the
sprue body (item 27).
7. Loosen the two SHCS (item 9) securing the stem to
the stem retainer (item 29).
8. Remove the front ring from the nozzle heater (not
shown).
9. Remove the nozzle heater snap ring (not shown).
10. Remove the nozzle heater (not shown).
11. Loosen the nozzle tip (item 24).
Figure 1 U500 & U750 SCVG assembly (typical)
Service Procedure 521-0 3 of 21
12. Insert the valve stem removal tool (HPN: 3512615)
into the injection side of the sprue body.
13. Gently tap the valve stem removal tool ensuring
contact with the stem (item 45) at all times until the
stem is tapped free from the sprue body.
14. Loosen the two sprue body retainer tab SHCS (item
10) from the air plate (item 39).
15. Loosen the cylinder SHCS (item 11) securing the
cylinder (item 34) to the air plate (item 39).
16. Pull the valve stem slider (item 28) and piston rods
(item 41) out of the sprue body (item 27).
17. Pull off the cylinder insert (item 33) from the air
plate (item 39).
18. Disengage the piston rods (item 41) from the piston
(item 40).
19. Pull the Melt Channel (M/C) reducer (item 36) out of
the air plate (item 39).
20. Pull the nozzle (item 23) out of the air plate (item
39).
21. Remove the weep fitting (item 25) from the sprue
body (item 27) to enable removal of the sprue body
heater (not shown).
22. Clean all parts after disassembly. Make sure the
sealing and contact surfaces are free of plastic,
grease, dirt, and dust.
23. Replace the Grafoil seals (item 22), piston seals
(items 18 & 19), cylinder insert seal (item 43), and air
plate seal (item 44) at each disassembly.
Service Procedure 521-0 4 of 21
Seal Replacement
All seals should be replaced each time the unit is
disassembled to ensure optimal sealing. Seal life is rated
at 250,000 cycles or 6 months (whichever occurs first).
Husky recommends having a spare Preventative
Maintenance (PM) kit on hand to facilitate easy seal
replacement.
NOTE: The following PM kits are available:
• SCVG 500 PM kit (HPN: 3509935)
• SCVG 750 PM kit (HPN: 3509936)
• SCVG 1000 PM kit (HPN: 3509937)
Stem Removal
1. Obtain a stem removal tool (Figure 2, HPN:
3512615).
Figure 2 Stem Removal Tool
Service Procedure 521-0 5 of 21
2. Loosen the four SHCS securing the sprue bushing
insert and remove them from the extruder pad.
3. Loosen the four SHCS securing the extruder pad and
remove them from the sprue body.
4. Loosen the two SHCS securing the stem retainer to
the stem slider.
5. Remove the front ring of the nozzle heater.
6. Remove the nozzle heater snap ring.
7. Loosen the nozzle tip.
Figure 3 SCVG Assembly
Service Procedure 521-0 6 of 21
Figure 4 Inserting the Valve Stem Removal Tool
8. Insert the valve stem removal tool into the injection
side of the sprue body.
9. Gently tap the valve stem removal tool ensuring
contact with the stem at all times, until the stem is
freed from the sprue body.
Service Procedure 521-0 7 of 21
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