{"product_id":"fleck-1800-bv-injector-throat-4-green","title":"Fleck 1800 BV Injector Throat, #4 Green","description":"\u003cp\u003eThis is the Fleck 1800 Brine Valve Injector Throat, size #4 Green (FL15127-04), a genuine Pentair metering part used in Fleck valves including the 3900. The injector throat works in tandem with the matching nozzle to form a venturi: as service water rushes through, it creates the suction that draws brine from the salt tank into the resin bed during regeneration. The throat is the receiving half of that venturi, and its precisely bored passage is critical to generating reliable suction.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eGenuine Fleck 1800 brine-valve injector throat\u003c\/li\u003e\n\u003cli\u003eSize #4, color-coded green for its specific flow rate\u003c\/li\u003e\n\u003cli\u003ePairs with the matching #4 green nozzle\u003c\/li\u003e\n\u003cli\u003eCompatible with Fleck 3900 control valves\u003c\/li\u003e\n\u003cli\u003ePrecision-bored for consistent brine draw\u003c\/li\u003e\n\u003cli\u003eLightweight metering part, about 0.05 lb\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThe throat's internal bore is sized with precision, and its green color code identifies the flow rate appropriate for a given tank diameter. Because the throat and nozzle share the same venturi passage and depend on each other's dimensions, they are best replaced together as a matched #4 set so the brine-draw geometry stays exactly as engineered. Pairing a fresh throat with a worn nozzle, or the wrong color, can compromise suction and leave regeneration incomplete.\u003c\/p\u003e\u003cp\u003eOn larger Fleck-equipped softeners, dependable brine draw is what fully recharges the softening resin during each cycle, which is essential to keeping hardness out of the home's water. Mineral scale, iron deposits, or sediment can gradually narrow or roughen the throat bore, weakening suction over time so that the resin only partly regenerates. This often appears as a slow return of hard-water symptoms even though the valve seems to be cycling normally. Replacing the injector throat during routine maintenance, ideally alongside its matching nozzle, restores the original venturi performance and keeps the 3900 valve drawing brine cleanly and efficiently for full, reliable softening.\u003c\/p\u003e\u003cp\u003eFor technicians, stocking matched #4 throat-and-nozzle sets ensures that injector service on a 3900-equipped system can always be completed correctly in one visit. Because the venturi geometry is so sensitive to wear and fouling, treating the throat and nozzle as a paired wear item, rather than replacing only the part that looks worst, yields the most consistent and long-lasting brine-draw performance for the customer over time.\u003c\/p\u003e","brand":"Pentair","offers":[{"title":"Default Title","offer_id":45668803379253,"sku":"FL15127-04","price":115.19,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0552\/4950\/2261\/files\/fl15127-04.jpg?v=1782533811","url":"https:\/\/watersoftenerplus.com\/vi-as\/products\/fleck-1800-bv-injector-throat-4-green","provider":"Water Softener Plus","version":"1.0","type":"link"}