Yes, I've done enough industrial maintenance to be familiar with that type of seal. The brass impeller alcohol pumps we ran at Gallo winery used them. Sealing something as thin and volatile as 99.5% pure grain alcohol from the distillery was a real challenge. The brass impellers were for "no spark" operation in case a failed bearing let the impeller touch the cast iron housing of the pump.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!