Heat Tracing; Sample Wetted Parts; Returning Samples To The Process Stream - Siemens Maxum Edition II Installation Manual

Gas Samples
Plan to transport gases at as low a pressure as possible, typically 35 to 103 kPa (5 to 15 psig)
or 35 kPa (5 psig) above the sample return pressure. The analyzer requires 34 kPa (5 psig) of
differential pressure. The pressure should be set at the probe site.
Liquid Samples
Liquids should have a minimum of 172 kPa (25 psig) differential between the sample take-off
and return points, allowing for a minimum liquid flow of 1.9 L/min (½ U.S. gal/min). Sample lines
of 9.53 mm (⅜") OD more than 30.5 m (100') long may require more than 172 kPa (25 psig)
differential.
3.7.1

Heat Tracing

See the Application Drawing Package, Block Diagram Utility Connections sheet.
Some sampling systems require heat tracing of the transport tubing. If heat tracing is required,
it will be noted on the Block Diagram Utility Connections sheet. It is essential that none of
transport tubing be exposed to ambient conditions. The tubing must be continuously traced,
insulated, and weather protected. Steam tracing must be continuously sloped downward for
draining any condensate, and it must have condensate traps at low points and at least every
15.2 m (50'). All joints and valves must also be heat traced, insulated, and weather proofed. The
tubing must be continuously traced through the analyzer house wall and up to the edge of the
sampling system cabinet. If steam tracing is used, it must be at the pressure recommended on
the Block Diagram Utility Connections sheet. If electrical tracing is used, it must be safe for the
hazardous area location. It must also be of the wattage recommended on the Block Diagram
Utility Connections sheet.
3.7.2

Sample Wetted Parts

Each Maxum II system is designed by Siemens to support the customer's specific application
needs. This includes the design of all parts coming into contact with the sample. Each system
is designed such that all sample-wetted parts (e.g. valves, fittings, tubing, etc.) are compatible
with the sample materials. This compatibility must be taken into account if any changes must
be made to the sample composition. See the Application Drawing Package for more
information regarding the materials for which a specific analyzer is designed.
3.7.3

Returning Samples to the Process Stream

See the Application Drawing Package, Sampling System sheet and Block Diagram Utility
Connections sheet.
If the sample stream is a gas and is to be released to the atmosphere, install a vent line outside
the analyzer house to at least 2.4 m (8') above the ground. The exhaust end should be curved
down, or a vent cap added for weather protection. If the sample gas is to be returned to a
pressurized line, a minimum pollution valve is required in the sampling system. The return line
Installation Manual
Installation Manual, 12/2019, 2000595 Rev 1
Installation Steps
3.7 Sampling System Installation
33