Drainage, Waste & VentQuestion 8 of 120
Which trap arrangement is expressly prohibited because it will siphon its own seal?
a.An S-trap
b.A P-trap vented within the permitted trap arm length
c.A drum trap serving a specialty fixture where approved
d.A deep seal trap on a floor drain
Explanation
An S-trap discharges vertically downward with no vent break, so the falling column of water pulls the seal out of the trap and is prohibited. A properly vented P-trap is the standard approved arrangement, and drum traps and deep seal traps remain permitted in specific approved applications.
Law Reference: IPC §1002.1Practice all 120 questions free — no signup required.
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