Magnum Venus Plastech Megaject MKIV Revision 1_2 - Manual (Page 24)

Megaject MK IV Issue 1_2 25/11/2003 Page 24 of 31
Servicing Injection Head
See drawing 22015
Note: During maintenance ensure resin and catalyst recirculation valves are in the
recirculate position. Avoid any cross contact of resin and catalyst.
Procedure
1. Remove air signal and solvent lines from the head. Using a 5mm allen key,
remove head block bolts. Split head into two sections. Remove head block O ring.
To remove NRV 3, first remove spring retaining pin at top of valve. Screw M8 bolt
partially into the valve and pull to remove from head.
2. NRV 2 may be unscrewed from the side port.
3. To remove NRV 1 unscrew from resin recirculation valve swivel fitting and then
remove from top head block.
4. To remove NRV 4, undo catalyst pipe swage fittings. Unscrew 3 way ball valve
from NRV 4. Unscrew NRV 4 from bottom head block.
5. Inspect all head block and NRV galleries. If hardened resin is evident, remove or
replace parts as necessary.
6. To disassemble all NRV’s, remove spring retaining pin. PTFE cone can be
replaced by removing spring from seat retainer.
7. When using a new PTFE cone, grind into NRV seat using thumb pressure only to
ensure a good seal. On reassembly a suitable hook must be used to stretch the
spring sufficiently to enable the retaining pin to be replaced.
8. Reassembly is a reversal of above procedures. Inspect head block O ring and
replace if necessary using a small amount of silicon grease to lubricate.
9. After reconnection of hoses and pipes, machine must be recirculated to expel air.
Note: We highly recommend catalyst and resin pipes are not removed from the recirculation
valves as leakage is inevitable.