154.826—Vapor compressors and blowers.
(a)
Each inlet and outlet to a compressor or blower which handles vapor that has not been inerted, enriched, or diluted in accordance with § 154.824 of this subpart must be fitted with:
(b)
If a reciprocating or screw-type compressor handles vapor in the vapor collection system, it must be provided with indicators and audible and visible alarms to warn against the following conditions:
(c)
If a liquid ring-type compressor handles vapor in the vapor collection system, it must be provided with indicators and audible and visible alarms to warn against the following conditions:
(d)
If a centrifugal compressor, fan, or lobe blower handles vapor in the vapor collection system, construction of the blades and/or housing must meet one of the following:
(5)
Blades of aluminum or magnesium alloy and a ferrous housing with a nonferrous insert sleeve at the periphery of the impeller.