Hankscraft push-pull bypass (41204) — one knob that slides, on the back of the head

The 41204 is the older Hankscraft bypass: a horizontal block clipped to the back of the valve head (RevV4 Service Manual, Figure 1-2: two adapters, two clips, meter in the outlet side). No wheel, no turning. One flanged knob on the end of the body drives one piston straight through it (manual parts list: Handle 8253013 ×1, Piston 8450001 ×1) — the knob slides in and out along the body. Runxin's dimension table for this part (their model F70C) puts the body at 218 mm long × 95 mm high with 1-inch connections, drawn here at about the width of the head, same scale as the ceramic-bypass animation. View: standing behind the unit, looking at the back of the valve — the same declared view as the Hankscraft ceramic files. Port sides follow the RevV4 manual's Figure 5-2 in this view (inlet left, outlet right), and the field check from the manual applies to this bypass too: the meter cable port is always on the OUTLET side.

PUSH-PULL BYPASS 41204 — BACK OF HEAD METER PORT = OUTLET SIDE ← KNOB OUT KNOB IN → (tip comes out this end) HANKSCRAFT — BACK OF HEAD SOFTENER TANK SALT TANK WATER IN (HARD) TO HOUSE SERVICE — knob OUT, water goes THROUGH the softener

Right now: SERVICE. The knob is pulled OUT — its shaft shows between the knob and the body, and the far end of the body is flush. That is the service picture in Runxin's own usage table for this part. One knob, one piston, no turning.

DIRECTION FLAG — CONTESTED, READ BEFORE TEACHING FROM THIS FILE. This animation follows Runxin's own F70 bypass manual, Usage table (§2.1), which pictures this exact part (F70C / 41204) in two rows labeled “Service” and “Bypass”: Service = knob pulled OUT (shaft showing at the knob end, far end flush); Bypass = knob pushed IN (knob against the body, piston tip sticking out of the far end). A Hankscraft dealer guide says the opposite in words — the Clean Water Store 7500-REV4 cabinet manual: “Pull the bypass valve handle out to put on the bypass” — and Aqua Pro's earlier field notes and quick guides carried that dealer direction (pushed in = service, pulled out = bypass). The two sources cannot both be right. Matthew: settle it on a real 41204 before this file is taught from — the telltale is physical: whichever state shows the piston shaft at the knob end AND a flush far end is the state Runxin's table calls service. Until that check is done, treat the direction in this file as manufacturer-documented but field-unverified. (The RevV4 manual's own Figure 1-2 labels its two arrows only “open” and “closed” — it does not say which word means service, so it settles nothing.)

Sources: Hankscraft Runxin RevV4 Service Manual — “Bypass Installation: Push Pull Bypass – 41204” (meter verified in the outlet side; seals into the animated connectors; attach the bypass and insert the clips; meter cable into the cable port on the outlet side), Figure 1-2 (exploded view: head at the back, Inlet / Outlet adapters ×2, Clip ×2, knob on the end of the horizontal body), parts list “41204 Plastic Bypass” (Connector 8945001 ×2, Impeller 5447007 ×1, Clip 8270004 ×2, Handle 8253013 ×1, Valve 2974052 ×1, Piston 8450001 ×1), and the System Packing List (“1-inch Push Pull Bypass 41204 ×1”). Runxin F70 bypass instruction manual (Wenzhou Runxin) — 41204 = old model F70C: 1-inch male inlet/outlet, 50 mm valve center distance, body 218 × 126 × 95 mm, flow 4.0 m³/h; characteristics: “can rotate or pull the handle to achieve bypass, part bypass and softening service”; Usage table §2.1 (the Service / Bypass pictures followed here); F70C parts list (same Handle 8253013 and Piston 8450001). Port sides: RevV4 manual Figure 5-2 (inlet left / outlet right in this behind-the-unit view) plus the meter-port rule — the same basis as the ceramic Hankscraft files. Evidence images saved beside this file: evidence-hankscraft-41204-runxin-usage.png, evidence-hankscraft-41204-runxin-dimensions.png, evidence-hankscraft-41204-revv4-fig1-2.png. Honest flags: (1) the push/pull DIRECTION is contested — see the flag box above; this file follows the manufacturer's labeled table, not the dealer sentence; (2) the exact travel distance is not printed in any source found — the two end positions are what the manual's pictures document, and the slide shown (~46 units) is schematic, not a measurement; (3) the inlet/outlet sides rest on Figure 5-2's drawing plus the meter-port check, exactly as flagged in the ceramic files; (4) both manuals draw the knob on the LEFT end in this view — if a field unit's knob sits on the right, the same slide logic applies mirrored. This bypass also shipped on some REV 2.5 systems (a RevV2.5 system manual lists “Push Pull Bypass – 41204”); the head drawn here is the REV4's back, and the bypass itself is the same part either way. Full notes: animations/research-notes.md §6; audit entry: animations/accuracy-audit.md.