Gas Safety Features - Emerson ROSEMOUNT NGA2000 HFID Instruction Manual

Instruction Manual
748297-E
June 2003
1-4

GAS SAFETY FEATURES

The HFID Analyzer Module is designed with a
factory-installed continuous dilution purge sys-
tem in accordance with standard ANSI/NFPA
496 - 1993, Chapter 6. Front-panel LEDs indi-
cate that the burner flame is lit and that the
purge system is enabled. In addition, fuel gas
is automatically shut off when a flame-out
condition occurs or the safety system is dis-
abled.
The purge system is enabled only if there is
proper purge gas flow in, purge gas pressure,
and internal case pressure, and after five
times the case volume has been exchanged.
All tubing ahead of the burner is rigid metallic
tubing assembled with ferrule/nut type com-
pression fittings. However, should an internal
fuel leak occur, a worst-case leak would be
Description and Specifications
1-2
Model NGA2000 HFID
dissipated below 25% of the LEL of hydrogen
through the combination of an inlet fuel flow
restrictor and purge gas flow.
This module is designed to use 40% H
He fuel at a maximum inlet pressure of 3446
hPa-gauge (50 psig).
A standard HFID Analyzer Module is only
equipped to analyze a non-flammable sample,
below 100% of the LEL..
POSSIBLE EXPLOSION HAZARD
Protection against explosion depends
upon a special fuel flow restrictor in the
fuel inlet fitting. Do not remove fuel inlet
restrictor. Do not use 100% hydrogen fuel.
Replace only with a factory supplied fit-
ting.
Rosemount Analytical Inc. A Division of Emerson Process Management
/60%
2
WARNING