NPK
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GAS CHARGE
NITROGEN GAS PRESSURE
The nitrogen gas pressure must be measured with no preload on the tool. Remove the
tool; or position the hammer with the tool fully extended against the tool retaining pin.
The hammer must not be resting vertical on the tool. The gas pressure in the hammer
will vary according to the gas temperature.
PREFERRED METHOD
The preferred method to measure or charge the nitrogen gas pressure is with the
hydraulic system temperature stabilized at maximum operating temperature. The chart
showing values for
“Operating Temperature”
should be used, see below.
ALTERNATE METHOD
The nitrogen gas pressure can be measured or charged at ambient temperature (cold),
before operating the hammer. See the chart
“Ambient Temperature”
below.
DO NOT OVERCHARGE THE HAMMER!
Exceeding the gas pre-charge specifications can result in damaging hammer
components. The NPK WARRANTY does not cover failures resulting from exceeding
the specified nitrogen gas pressure.
NITROGEN GAS PRE-CHARGE SPECIFICATIONS
MODEL
AT AMBIENT TEMPERATURE
(cold, before operating)
PSI (BAR)
(plus 0, minus 25)
AT OPERATING TEMPERATURE
PSI (BAR)
(plus 0, minus 25)
GH7
350 (24)
405 (28)
GH9
365 (25)
420 (29)
GH10
GH12
GH15
GH18
GH23
390 (27)
450 (31)
GH30
GH40
GH50
GAS CHARGING KIT
ALL NPK HYDRAULIC HAMMERS are furnished with the following gas charging kit. In
addition, a nitrogen tank and pressure regulator valve (not furnished with the hammer)
are required. These can be obtained from your local welding supply house. A regulator
valve is available from NPK.
GAS CHARGE KIT (PART NO. 7300588)
g1. CHARGE ADAPTER (PART NO. 30604040)
g3. PLUG (PART NO. 30102050)
g4. HOSE (PART NO. 20118010)
g5. CHARGING KIT BOX (PART NO. 35001030)
g7. OPTIONAL REGULATOR VALVE
(PART NO. 21101060)
Summary of Contents for GH10
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