The fastest flowing pipe in street (8)

I believe the answer is:

nippiest

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'the fastest' is the definition.
I can't judge whether this defines the answer.

'flowing pipe in street' is the wordplay.
'flowing' is an anagram indicator.
'street' becomes 'st'.
'pipe'+'in'='pipein'
'pipein' anagrammed gives 'nippie'.
'nippie'+'st'='NIPPIEST'

Can you help me to learn more?

(Another definition for nippiest that I've seen is " most cold".)

I've seen this clue in the Irish Times.

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