Instruction manual

SM425 INSTRUCTION MANUAL 4.0 PIPING
4.2 Piping for System 2
Piping in System 2 is illustrated in Figure 4-7.
Figure 4-7 Piping for System 2
System 2 illustrated in Figure 4-7 requires piping as follows:
• Connect a stop valve or check valve to the nipple at the reference gas inlet of the detector.
• If a high-temperature detector is used and the sample gas is under negative pressure, connect an
auxiliary ejector to the sample gas exhaust hole of the high-temperature probe adapter (see
Section 1.18.4, Figure 4-3).
• If a high-temperature detector is used and the pressure of the measured gas is 0.5 kPa or higher,
it is recommended a needle valve (throttle) be used in the sample gas exhaust of the high-
temperature probe adapter (see Section 1.18.4, Figure 4-4).
- A throttle valve is used to lower the sample gas temperature below 700°C. If the process is at high
temperature and pressure, the sample gas temperature may not fall to below 700°C before it reaches the
detector.
If the sample gas temperature is lowered too much, condensation may be produced in the high-
temperature probe adapter. During wintertime it is recommended the probe adapter be protected with an
insulating material to avoid condensation forming (see Section 1.18.4, Figure 4-5).
Refer to Section 1.11.2 for guidelines on using the high-temperature probe adapter.
• The air feed for blow-back should also be taken into consideration if blow-back is being used to
reduce particulate clogging in the high-temperature probe adapter and detector.
72 42500001 REV A