Hypertherm HT4001 Plasma Arc Cutting System - Manual (Page 126)

OPERATION
11-96
HT4001
Instruction Manual 5-35
Changing the Water Tube
Problems and causes you may find with a defective or improperly installed water tube:
• Short electrode life: Water tube not screwed in tightly; wrong water tube for consumables
• Flow switch interlock shutting down the system: Water flow restricted due to loose water tube.
• Humming or rattling sound coming from the torch: Water tube bent or loose
If you suspect a problem with the water tube, you may need to replace it.
1. Disconnect power supply from power source.
2. Remove all consumables from torch (see Changing Consumable Parts earlier in this section.
3. Verify that the correct water tube is installed – The standard water tube (020990) is recessed about 5/64 of an
inch (2 mm) from the end of the torch head. The nitrogen beveling water tube (020991) extends about 19/64 of
and inch (7.5 mm) from the end of the torch head. The oxygen beveling water tube (020992) extends about
23/64 of an inch (9.1 mm) from the end of the torch head.
Note: part numbers are laser engraved on the water tubes.
4. Look for any damage or bends in the water tube.
5. Remove and replace the water tube by using the water tube wrench (027347) supplied with the consumable
parts kits – Fig. 5-11. When installing water tube, do not overtighten! Snug down by hand only.
Figure 5-11 Changing the Water Tube
WARNING
Always disconnect the power supply
from the main power source before
inspecting or changing the torch parts.