OPERATION MANUAL Sumitomo Heavy Industries, Ltd.
SRDK Series CRYOCOOLER 42
4-2 HELIUM LEAK
4-2 HELIUM LEAK
<Warning about explosion, escape of gas>
This cryocooler (cold head, compressor unit, compressor adsorber, flex lines) contains a high-
pressure (about 1.62 MPa (16.5 kgf/cm
2
G, 235 psig)) helium gas sealed in. Hitting the
equipment with a sharp edge or touching it with a pointed object may cause explosion or escape
of gas. Handle the equipment with extreme care.
The Cold Head cannot be performed a required cooling power in normal operations, as the result of the
He-gas pressure reducing gradually in the Cold Head in condition of occurring a He-gas Leak in the
Cryocooler. The Compressor unit will be shut down as the function of the Low Pressure Switch to be
sensed and excessive lower He-gas pressure, and verify the charged He-gas pressure in the Compressor
Unit as specified pressure. The charged He-gas pressure will be indicated individually for each
application, and see “TECHNICAL INSTRUCTION” of the Cold Head used.
COLD HEAD MODEL STATIC PRESSURE
RDK-408D2 4K Cold Head
RDK-408D 4K Cold Head
RDK-415D 4K Cold Head
1.60 - 1.70 MPa at 20 deg.C (68 deg.F)
(16.3 - 17.3 kgf/cm
2
G, 232 - 246 psig)
RDK-408S2 10K Cold Head
RDK-408S 10K Cold Head
RDK-400B Single Stage Cold Head
1.45 - 1.55 MPa at 20 deg.C (68 deg.F)
(14.8 - 15.8 kgf/cm
2
G, 210 - 225 psig)
A Leak detector will be applied to leak area hunting for convenience, and “Liquid Leak Detector” also will
be useful to check the He-gas leaking of couplings for the Flex Line by watching any bubbling carefully, if
the Leak Detector not in use at the field.
WARNING