Instruction manual

STP-200/300/400 Series Instruction Manual
7.3 Gas Suction
◇ When pumping gases, they may remain in the STP pump. Introduce
a purge gas and then exhaust all gasses.
Residual gases in the STP pump may cause an accident when the
STP pump is removed.
Confirm the characteristics of gases to be used, referring to the
Material Safety Data Sheet (MSDS) you obtain from the gas supplier.
◇ Chlorine or fluorine system gases can be used in the chemical
specific STP-200C/300C/400C (type C). When you use gases
including alkaline metals, but excluding Li, gases including Ga, Hg,
In, or Sn, or HBr, contact BOC Edwards (See Section 1.1, "Usable
Gases").
◇ NEVER use corrosive gases (chlorine, fluorine, or other system
gases) in the STP-200/300/400 pump or other models without
anti-corrosion treatment.
◇ Cool the STP pump to prevent the STP pump from overheating when
pumping gases (See Section 7.2," Cooling the STP Pump" ).
7.3.1 How to Introduce a Purge Gas (for Chemical Specific Pump Type C)
When pumping reactive or corrosive gases, introduce a purge gas to protect the
inside of the STP pump.
1) Connect a needle valve or a similar part to the purge port and introduce a dry
N
2
gas or other gas to perform a gas purge (See Section 3.3.6, "Connecting the
Purge Port").
2) The proper amount of the gas purge is approx.1.7×10
-2
Pa·m
3
/sec (10SCCM).
The allowable gas pressure ranges from zero (atmospheric pressure) to
0.5 kgf/cm
2
(gauge pressure).
◇ When not using the purge port, always mount the blank flange
(attached at delivery).
◇ High-pressure at the inlet port may result in a noise. This is no
abnormality/error.
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