The REV4's ceramic bypass clips to the back of the valve head — no levers, no plumbing loop. On top of the bypass body sits one round handwheel: turn it, and a ceramic disc inside does the switching. (Some REV4 systems ship with a push-pull bypass instead — pull-out handle; see the note below.) View: standing behind the unit, looking at the back of the valve. The port sides in this view follow Hankscraft's own manual (RevV4 Service Manual, Figure 5-2), which labels the inlet on the left and the outlet on the right in this behind-the-unit view. Hankscraft never states the sides in words, so the drawing also marks the field check from §6 of the manual: the meter cable port is always on the OUTLET side.
Right now: SERVICE. The handwheel's pointer sits at SERVICE. One wheel does the whole job — there are no handles to match up on this valve.
Source: Hankscraft Runxin RevV4 Service Manual §6 (Ceramic Bypass 41206/41207) and Runxin's bypass documentation ("through turning the handwheel… service, close, bypass"). Dealer guides phrase it as "turn the knob… turn the bypass SLOWLY." CORRECTED 2026-11-02 (accuracy audit): the head is now drawn from the back (the earlier version drew the front display while claiming a behind-the-unit view — the same view mix-up Matthew caught on the Clack file), and the meter port is marked on the outlet side. Honest flags: (1) the exact degrees between the service and bypass stops are not printed in the manual — drawn here as about a quarter turn; (2) the inlet/outlet sides rest on the manual's Figure 5-2 drawing alone — Hankscraft never states them in words — so on a real unit the meter cable port is the decider: it is always on the outlet side (manual §6 and start-up steps). VARIANT: some RevV4 systems ship with the 1-inch Push-Pull Bypass 41204 instead (it is in the RevV4 system packing list): pushed IN = service, pulled OUT = bypass. Full notes: animations/research-notes.md.