{"product_id":"spirotech-spirocross-ax125j-1-1-4in-hydraulic-separator-heat-pump","title":"Spirotech SpiroCross AX125J 1-1-4in Hydraulic Separator Heat Pump","description":"\u003cdiv style=\"font-size:16px; max-width:900px; font-family:Arial,Helvetica,sans-serif; color:#222; line-height:1.65;\"\u003e\n\n\u003cdiv style=\"background:#008377;color:#fff;border-radius:6px;padding:10px 18px;margin-bottom:18px;font-weight:700;font-size:0.95em;letter-spacing:.04em;\"\u003e\nHEAT PUMP \u0026amp; MULTI-CIRCUIT SYSTEM COMPONENT — HYDRAULIC SEPARATOR WITH AIR \u0026amp; DIRT SEPARATION\n\u003c\/div\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eSpirotech SpiroCross AX125J\u003c\/strong\u003e is the \u003cstrong\u003eRp 1¼\" variant\u003c\/strong\u003e of\nthe AX-J hydraulic separator series, designed for \u003cstrong\u003elarger heat pump installations, apartment building\nshared systems, and commercial multi-circuit HVAC applications\u003c\/strong\u003e where the AX100J's\n2.0 m³\/h capacity is insufficient. With a \u003cstrong\u003emaximum flow rate of 3.6 m³\/h\u003c\/strong\u003e,\nit covers the primary circuit demands of most mid-range air or ground-source heat pumps up to\napproximately \u003cstrong\u003e20–25 kW\u003c\/strong\u003e at typical Δt values. Like the AX100J, it combines\n\u003cstrong\u003ehydraulic balancing, microbubble air deaeration, and neodymium magnetic dirt separation\u003c\/strong\u003e\nin a single \u003cstrong\u003ebrass unit\u003c\/strong\u003e with an identical footprint — no additional floor space\nrequired when upgrading from a 1\" to a 1¼\" installation.\u003c\/p\u003e\n\n\u003cdiv style=\"display:flex;flex-wrap:wrap;gap:0;background:#008377CF;color:#fff;border-radius:6px;padding:12px 16px;margin:22px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:110px;text-align:center;padding:6px 4px;\"\u003e\n\u003cdiv style=\"font-size:1.25em;font-weight:700;\"\u003e3-in-1\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.78em;opacity:.85;\"\u003eHydraulic + Air + Dirt\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;text-align:center;padding:6px 4px;\"\u003e\n\u003cdiv style=\"font-size:1.25em;font-weight:700;\"\u003e10 bar\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.78em;opacity:.85;\"\u003eMax pressure\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;text-align:center;padding:6px 4px;\"\u003e\n\u003cdiv style=\"font-size:1.25em;font-weight:700;\"\u003e110 °C\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.78em;opacity:.85;\"\u003eMax temperature\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;text-align:center;padding:6px 4px;\"\u003e\n\u003cdiv style=\"font-size:1.25em;font-weight:700;\"\u003e3.6 m³\/h\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.78em;opacity:.85;\"\u003eMax flow rate\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;text-align:center;padding:6px 4px;\"\u003e\n\u003cdiv style=\"font-size:1.25em;font-weight:700;\"\u003eRp 1¼\"\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.78em;opacity:.85;\"\u003eBSP connection\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;text-align:center;padding:6px 4px;\"\u003e\n\u003cdiv style=\"font-size:1.25em;font-weight:700;\"\u003e20 yr\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.78em;opacity:.85;\"\u003eSpiroLIFE warranty\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"border-left:4px solid #c0392b;background:#fff5f4;padding:12px 16px;margin:14px 0;border-radius:0 4px 4px 0;\"\u003e\n\u003cstrong style=\"color:#c0392b;\"\u003eINSTALLATION — ORIENTATION AND PIPEWORK\u003c\/strong\u003e\u003cbr\u003eAs with the AX100J, the AX125J must be \u003cstrong\u003emounted in horizontal pipework with the integral air vent on top\u003c\/strong\u003e. No directional arrow — either connection serves as inlet or outlet. Connect the \u003cstrong\u003ehigher-temperature circuit to the upper connections\u003c\/strong\u003e. Allow at least \u003cstrong\u003e100mm straight pipe before and after\u003c\/strong\u003e. At 6.9 kg dry weight, ensure pipework support is independently bracketed — do not rely on the pipe joints alone to carry the unit weight.\u003c\/div\u003e\n\n\u003cdiv style=\"border-left:4px solid #d35400;background:#fffbf0;padding:12px 16px;margin:14px 0;border-radius:0 4px 4px 0;\"\u003e\n\u003cstrong style=\"color:#d35400;\"\u003eAX100J vs AX125J — SIZE SELECTION\u003c\/strong\u003e\u003cbr\u003eBoth models share \u003cstrong\u003eidentical external dimensions\u003c\/strong\u003e (H 462mm, L 236mm, D 84mm). The only hydraulic difference is the \u003cstrong\u003econnection size and flow capacity\u003c\/strong\u003e: AX100J handles up to 2.0 m³\/h on Rp 1\" pipework; AX125J handles up to 3.6 m³\/h on Rp 1¼\". Select by matching the nominal size of your primary circuit pipework. If the system operates near the upper flow limit, choose the \u003cstrong\u003elarger AX125J\u003c\/strong\u003e to avoid exceeding the 1 m\/s velocity limit that degrades hydraulic separation efficiency.\u003c\/div\u003e\n\n\u003cdiv style=\"border-left:4px solid #008377;background:#f0faf9;padding:12px 16px;margin:14px 0;border-radius:0 4px 4px 0;\"\u003e\n\u003cstrong style=\"color:#008377;\"\u003eIDENTICAL FOOTPRINT — LARGER CAPACITY\u003c\/strong\u003e\u003cbr\u003eBecause both AX100J and AX125J share the same physical envelope, it is straightforward to specify the AX125J in any installation where future heat pump upsizing is a possibility. The additional \u003cstrong\u003e0.4 kg weight difference\u003c\/strong\u003e is the only physical change; pipework adaptors from Rp 1¼\" to smaller pipe sizes are readily available if needed in the short term.\u003c\/div\u003e\n\n\u003cdiv style=\"display:flex;flex-wrap:wrap;gap:14px;margin:20px 0;\"\u003e\n\u003cdiv style=\"flex:1;min-width:220px;background:#f8f8f8;border-radius:6px;padding:16px 18px;\"\u003e\n\u003ch3 style=\"margin:0 0 8px;font-size:1em;border-bottom:2px solid #008377;padding-bottom:4px;\"\u003eHigher-Flow Hydraulic Separation\u003c\/h3\u003e\n\u003cp style=\"margin:0;font-size:0.95em;\"\u003eAt 3.6 m³\/h, the AX125J covers the primary circuit flow of most residential and light-commercial heat pumps. The SpiroTube ensures \u003cstrong\u003eminimal fluid mixing\u003c\/strong\u003e between primary and secondary loops, maintaining the temperature differential that drives heat pump efficiency — a critical factor on systems where secondary zone valves open and close frequently.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:220px;background:#f8f8f8;border-radius:6px;padding:16px 18px;\"\u003e\n\u003ch3 style=\"margin:0 0 8px;font-size:1em;border-bottom:2px solid #008377;padding-bottom:4px;\"\u003eSame Neodymium Magnet Specification\u003c\/h3\u003e\n\u003cp style=\"margin:0;font-size:0.95em;\"\u003eThe AX125J uses the \u003cstrong\u003esame neodymium magnet\u003c\/strong\u003e specification as the AX100J — a full-width collector that captures magnetite in the 1.3-litre internal volume. On a larger system with more pipework surface area to corrode, maintaining this collection capacity is more important, not less. Draining the collection chamber is completed in seconds while the system runs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:220px;background:#f8f8f8;border-radius:6px;padding:16px 18px;\"\u003e\n\u003ch3 style=\"margin:0 0 8px;font-size:1em;border-bottom:2px solid #008377;padding-bottom:4px;\"\u003eViton-Sealed Valve Construction\u003c\/h3\u003e\n\u003cp style=\"margin:0;font-size:0.95em;\"\u003eThe integral air vent uses a \u003cstrong\u003eViton-sealed float valve\u003c\/strong\u003e — a material chosen for long-term compatibility with both water and glycol solutions across the full 0–110 °C operating range. This is the same specification as the AX100J and is a direct contributor to the 20-year SpiroLIFE warranty backing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:220px;background:#f8f8f8;border-radius:6px;padding:16px 18px;\"\u003e\n\u003ch3 style=\"margin:0 0 8px;font-size:1em;border-bottom:2px solid #008377;padding-bottom:4px;\"\u003eSuitable for New Build and Retrofit\u003c\/h3\u003e\n\u003cp style=\"margin:0;font-size:0.95em;\"\u003eThe AX125J is designed for \u003cstrong\u003enew build, refurbishment, and retrofit\u003c\/strong\u003e applications. Rp 1¼\" BSP threading is standard in commercial plant rooms and larger residential boiler houses. Spirotech recommends a full system power-flush and water quality check before fitting to ensure the separator operates in clean system water from day one.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003ch3 style=\"color:#008377;border-bottom:2px solid #008377;padding-bottom:6px;margin-top:28px;\"\u003eTechnical Specification — SpiroCross AX125J (Rp 1¼\")\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x:auto;margin:22px 0;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-family:inherit;\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\u003cth colspan=\"2\" style=\"background:#008377CF;color:#fff;padding:8px 12px;text-align:left;font-size:0.9em;\"\u003eConnection \u0026amp; Hydraulics\u003c\/th\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eArticle Number\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eAX125J\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eProduct Type\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eSpiroCross AX-J Hydraulic Separator — Rp 1¼\" threaded fitting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eConnection\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eRp 1¼\" BSP internal thread\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMax Flow Rate\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e3.6 m³\/h\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMax Flow Velocity\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e1.0 m\/s\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003cth colspan=\"2\" style=\"background:#008377CF;color:#fff;padding:8px 12px;text-align:left;font-size:0.9em;\"\u003eOperating Limits\u003c\/th\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMax Operating Pressure\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e10 bar (bar-g)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMax Temperature\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e110 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMedium\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eWater \/ glycol (max 50% v\/v)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eDesign Standard\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eEN 13445\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eCE Marking\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e2014\/68\/EU (Pressure Equipment Directive)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003cth colspan=\"2\" style=\"background:#008377CF;color:#fff;padding:8px 12px;text-align:left;font-size:0.9em;\"\u003eConstruction Materials\u003c\/th\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eBody\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eBrass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eConnections\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eBrass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eFittings\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eBrass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eDeaeration Cap\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eBrass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eValve Sealing\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eViton\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eFloat\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003ePolypropylene (PP)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eDrain Valve\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eBrass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eSpirotube Tube\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eS235 JRG2 (structural steel)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eSpirotube Wire\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eCopper\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eSpirotube Solder\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eTin (SnCu3)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMagnet\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eNeodymium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003cth colspan=\"2\" style=\"background:#008377CF;color:#fff;padding:8px 12px;text-align:left;font-size:0.9em;\"\u003ePhysical Dimensions\u003c\/th\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eTotal Height (H)\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e462 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eLower Height (h)\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e135 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eConnection Height (h1)\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e144 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eUpper Height (h2)\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e183 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eLength (L)\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e236 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eBody Diameter (D)\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e84 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eWidth (b)\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e53 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMin clearance above (x)\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e\u0026gt;100 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMin clearance below (y)\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e\u0026gt;50 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eAir Vent Port (e)\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eG 3\/4\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eDrain Port (e2)\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eR 1\/2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eInternal Volume\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e1.3 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eDry Weight\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e6.9 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003cth colspan=\"2\" style=\"background:#008377CF;color:#fff;padding:8px 12px;text-align:left;font-size:0.9em;\"\u003evs AX100J — Key Differences\u003c\/th\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eConnection\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eRp 1¼\" (AX100J: Rp 1\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eMax Flow\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e3.6 m³\/h (AX100J: 2.0 m³\/h)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eDry Weight\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e6.9 kg (AX100J: 6.5 kg)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eAll Other Dimensions\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003eIdentical to AX100J\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003cth colspan=\"2\" style=\"background:#008377CF;color:#fff;padding:8px 12px;text-align:left;font-size:0.9em;\"\u003eTesting \u0026amp; Warranty\u003c\/th\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eLeakage Test\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003eYes — test medium: air\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eDesign \u0026amp; Manufacturing\u003c\/td\u003e\n\u003ctd style=\"background:#fff;padding:7px 12px;font-size:0.9em;\"\u003e2014\/68\/EU compliant\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-weight:600;width:50%;font-size:0.9em;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"background:#f4fafa;padding:7px 12px;font-size:0.9em;\"\u003e20 years — SpiroLIFE\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\n\u003ch3 style=\"color:#008377;border-bottom:2px solid #008377;padding-bottom:6px;margin-top:28px;\"\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cdiv style=\"margin:22px 0;\"\u003e\n\u003cdetails style=\"border:1px solid #ddd;border-radius:4px;margin:8px 0;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:10px 14px;cursor:pointer;font-weight:600;border-radius:4px;list-style:none;\"\u003eWhat heat pump sizes is the AX125J designed for?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 16px;font-size:0.95em;\"\u003eAt 3.6 m³\/h maximum flow, the AX125J typically suits heat pump primary circuits in the \u003cstrong\u003e12–25 kW output range\u003c\/strong\u003e depending on the primary circuit Δt. At a heat pump primary Δt of 5 K, 3.6 m³\/h equates to approximately 20–21 kW thermal. Always confirm the primary circuit design flow rate with the heat pump manufacturer's hydraulic specification before selecting between AX100J and AX125J.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #ddd;border-radius:4px;margin:8px 0;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:10px 14px;cursor:pointer;font-weight:600;border-radius:4px;list-style:none;\"\u003eWhy do the AX100J and AX125J have the same external dimensions?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 16px;font-size:0.95em;\"\u003eSpirotech deliberately designed the AX-J range with a \u003cstrong\u003ecommon footprint\u003c\/strong\u003e so that engineers can upgrade from Rp 1\" to Rp 1¼\" connection without redesigning the plantroom layout. The only physical differences are the connection thread size and a 0.4 kg weight increase — the body, mounting points, and service clearances are identical.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #ddd;border-radius:4px;margin:8px 0;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:10px 14px;cursor:pointer;font-weight:600;border-radius:4px;list-style:none;\"\u003eCan I use the AX125J on a system with three or more secondary circuits?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 16px;font-size:0.95em;\"\u003eYes — the low-loss header function of the SpiroCross is not limited to two circuits. The \u003cstrong\u003eprimary circuit connects to the upper two ports\u003c\/strong\u003e (flow and return) and the secondary manifold circuit connects to the lower two ports. Multiple zone pumps on the secondary side are individually hydraulically isolated from the primary by the SpiroTube, regardless of how many zones are active.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #ddd;border-radius:4px;margin:8px 0;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:10px 14px;cursor:pointer;font-weight:600;border-radius:4px;list-style:none;\"\u003eDoes the AX125J require a separate expansion vessel connection?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 16px;font-size:0.95em;\"\u003eYes. As with all low-loss header installations, the \u003cstrong\u003eexpansion vessel should be connected on the suction side of the secondary circuit pump\u003c\/strong\u003e. Spirotech's installation diagram for the AX-J series shows this connection explicitly. The AX125J body itself does not have a dedicated expansion port — the vessel connects to the closest pipework tapping in the secondary circuit.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #ddd;border-radius:4px;margin:8px 0;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:10px 14px;cursor:pointer;font-weight:600;border-radius:4px;list-style:none;\"\u003eIs the AX125J compatible with R290 (propane) heat pumps?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 16px;font-size:0.95em;\"\u003eThe AX125J operates on the \u003cstrong\u003ewater\/glycol side of the heat pump system\u003c\/strong\u003e — it does not contact the refrigerant circuit. R290 heat pumps use the same hydraulic primary circuit specification as other refrigerant types. The AX125J is compatible with any heat pump where the primary circuit water conditions fall within 10 bar, 110 °C, and 50% glycol.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #ddd;border-radius:4px;margin:8px 0;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:10px 14px;cursor:pointer;font-weight:600;border-radius:4px;list-style:none;\"\u003eHow does the AX125J differ from a standard plumbing low-loss header?\u003c\/summary\u003e\u003cdiv style=\"padding:12px 16px;font-size:0.95em;\"\u003eA standard low-loss header provides hydraulic separation only. The AX125J additionally provides \u003cstrong\u003eactive microbubble air deaeration\u003c\/strong\u003e via the factory-fitted automatic air vent, and \u003cstrong\u003eneodymium magnetic dirt separation\u003c\/strong\u003e via the integral collection chamber. This three-in-one functionality eliminates the need for separate SpiroVent and SpiroTrap units on the primary\/secondary connection, reducing installation time, leak points, and equipment cost.\u003c\/div\u003e\u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"Spirotech","offers":[{"title":"Default Title","offer_id":64950238216541,"sku":"AX125J","price":595.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/SpirotechSpiroCrossAX100J1inHydraulicSeparatorHeatPump.jpg?v=1781163012","url":"https:\/\/qualityheating.co.uk\/products\/spirotech-spirocross-ax125j-1-1-4in-hydraulic-separator-heat-pump","provider":"AIZO Quality Heating","version":"1.0","type":"link"}