428 Oxygen-Enhanced Combustion
A ow element (FE104) is recommended to provide a
measure of the oxygen ow rate. CGA G-4.4 (Sections
4.7 and 5.4) provides general guidelines for ow ele-
ment selection. Flow elements may include orice plates
(monel material is recommended), annubars, vortex
meters, mass ow meters, and others, provided that all
of the materials are oxygen compatible and dimensional
requirements are satised. Glass tube ow meters
(rotameters) are not recommended. If used, safeguards
against personnel injury must be provided per NFPA 86
(Section 4-4.3.10).
Low and high oxygen ow limit switches (FSL/H104)
are required per NFPA 86 (Sections 5-14.3 and 5-14.4).
The ow limit switches must be interlocked to close
the automatic sa ...