Hypertherm XPR170, Instruction Manual

Page: 56 / 438

Qualifications and Requirements
2
56 809480 Instruction Manual XPR300
Flow requirements for coolant

The maximum coolant flow rate is 11.36 liters per minute (3.0 US gallons per minute).

The minimum coolant flow rate is 3.79 liters per minute (1 US gallon per minute).
The cutting systems stops automatically if the flow rate reaches this maximum or minimum flow rate.
Automatic, low-flow shut-off protects the coolant pump from damage from low-flow or no-flow
conditions. Automatic, high-flow shut-off protects the torch and leads from damage from a blow-out
event.
For information about how to diagnose and troubleshoot coolant flow issues, refer to:

Low coolant flow codes (540 – 542) on page 319

High coolant flow codes (543 – 544) on page 321
Purity requirements for coolant water
Always use water that meets the specifications in Table 12 on page 56 when using a custom
coolant mix.
Water that is too pure can also cause problems. Deionized water can cause corrosion in the coolant
system. After deionization, add benzotriazole (128020).
Use water purified by any method (deionization, reverse osmosis, sand filters, water softeners, etc.)
as long as the water purity meets the specifications in the table below. Contact a water specialist for
advice in choosing a water filtration system.
Table 12 – Purity measurement methods for coolant water
Methods to measure water purity
Water purity level
Conductivity μS/cm
at 25°C (77°F)
Resistivity mΩ∙cm
at 25°C (77°F)
Dissolved solids
or hardness (ppm
of NaCl)
Grains per gallon
(gpg of CaCO
2
)
Pure water
(For reference only. Do not
use.)
0.055 18.3 0 0
Maximum purity 0.5 2 0.206 0.010
Minimum purity 18 0.054 8.5 0.43
Maximum potable water
(For reference only. Do not
use.)
1000 0.001 495 25