{"product_id":"valvula-diafragma-anticorrosiva-pfa-wcb-ansi-150","title":"Corrosion-Resistant Diaphragm Valve WCB | PFA Lined | ANSI 150 | Acids \u0026 Chemicals","description":"\u003ch2\u003eCorrosion-Resistant Diaphragm Valve — WCB Body with PFA Lining, ANSI 150 Flange, ½\" to 4\"\u003c\/h2\u003e\u003cp\u003e  The \u003cstrong\u003ecorrosion-resistant diaphragm valve with PFA lining\u003c\/strong\u003e is fundamentally different from all ball, butterfly, and globe valves in the catalog in one decisive aspect: \u003cstrong\u003ethe only moving component that touches the fluid is the flexible diaphragm\u003c\/strong\u003e — there is no stem, ball, or obturator exposed to the aggressive fluid. The metal stem pushes the diaphragm from the outside against the body weir to close, and releases it to open, but never penetrates the fluid space. This complete separation between the operating mechanism and the aggressive fluid is the fundamental advantage of the diaphragm valve for services involving concentrated acids, strong oxidizers, and high-purity fluids.\u003c\/p\u003e\u003cp\u003e  The diaphragm is a two-layer construction: an \u003cstrong\u003eEPDM\u003c\/strong\u003e core that provides the elasticity and recovery force needed to repeatedly seal and open, with an outer face of \u003cstrong\u003ePFA (or FEP)\u003c\/strong\u003e which is the only surface in contact with the fluid — resistant to virtually all acids, alkalis, and oxidizers that would destroy any conventional elastomer. The WCB body with PFA internal lining completes the total protection of the metal.\u003c\/p\u003e\u003ch3\u003eWhy the diaphragm valve is different from the ball valve for aggressive fluids\u003c\/h3\u003e\u003cp\u003e  Both the PFA corrosion-resistant ball valve and the PFA corrosion-resistant diaphragm valve handle extreme corrosive fluids — but they have distinct technical advantages that determine when to use each:\u003c\/p\u003e\u003ctable\u003e  \u003cthead\u003e    \u003ctr\u003e      \u003cth\u003eCriterion\u003c\/th\u003e      \u003cth\u003ePFA Diaphragm Valve ← This product\u003c\/th\u003e      \u003cth\u003ePFA Corrosion-Resistant Ball Valve\u003c\/th\u003e    \u003c\/tr\u003e  \u003c\/thead\u003e  \u003ctbody\u003e    \u003ctr\u003e      \u003ctd\u003eStem in contact with fluid\u003c\/td\u003e      \u003ctd\u003e✅ Never — stem does not penetrate the fluid space\u003c\/td\u003e      \u003ctd\u003ePFA-lined stem but inside the body\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003eFlow with fine suspended solids\u003c\/td\u003e      \u003ctd\u003e✅ Suitable — no cavities for solids to accumulate\u003c\/td\u003e      \u003ctd\u003e⚠️ Solids can accumulate in the ball cavity\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003eNon-turbulent flow\u003c\/td\u003e      \u003ctd\u003e✅ Smooth Weir-type flow characteristic\u003c\/td\u003e      \u003ctd\u003eMore direct flow but with turbulence in partial opening\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003ePressure drop in open position\u003c\/td\u003e      \u003ctd\u003eHigher — the weir creates flow resistance\u003c\/td\u003e      \u003ctd\u003e✅ Lower — practically direct passage\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003eProportional modulating control\u003c\/td\u003e      \u003ctd\u003e✅ Suitable — linear-type flow characteristic\u003c\/td\u003e      \u003ctd\u003eON\/OFF only in standard ball valve\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003eMaximum working pressure\u003c\/td\u003e      \u003ctd\u003e290 psi (20 bar) — limited by diaphragm\u003c\/td\u003e      \u003ctd\u003e✅ 290 psi (20 bar) — similar in ANSI 150\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003eHigh-purity fluids without metal contamination\u003c\/td\u003e      \u003ctd\u003e✅ Ideal — zero metal-fluid contact possible\u003c\/td\u003e      \u003ctd\u003e✅ Also suitable with integral PFA lining\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003eCrystallizing or sticky fluids\u003c\/td\u003e      \u003ctd\u003e✅ Smooth PFA prevents adhesion\u003c\/td\u003e      \u003ctd\u003e⚠️ Can accumulate in the ball cavity\u003c\/td\u003e    \u003c\/tr\u003e  \u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eThe double EPDM + PFA diaphragm — how it works\u003c\/h3\u003e\u003cp\u003e  The diaphragm is the technical heart of this valve. The two-layer construction solves the fundamental problem of single-material diaphragms:\u003c\/p\u003e\u003cul\u003e  \u003cli\u003e    \u003cstrong\u003eInner face (in contact with fluid) — PFA\/FEP:\u003c\/strong\u003e The PFA or FEP fluoropolymer on the diaphragm face that touches the fluid provides practically universal chemical resistance — compatible with HF, concentrated H₂SO₄, concentrated HCl, ClO₂, H₂O₂, and virtually any strong acid, alkali, or oxidizer. PFA does not degrade, swell, or release any compounds into the fluid — essential in high-purity applications.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eOuter face (in contact with mechanism) — EPDM:\u003c\/strong\u003e The EPDM core provides the elasticity and recovery force necessary for the diaphragm to seal tightly against the weir when closing and regain its shape correctly when opening. A pure PFA diaphragm would be too rigid for this flexing cycle — EPDM is the correct material for mechanical support.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eResult:\u003c\/strong\u003e A diaphragm that has the chemical resistance of PFA where it matters (the face touching the fluid) and the elasticity of EPDM where it is needed (the mechanical support for the flexing cycle).  \u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eWeir-type body — non-turbulent flow\u003c\/h3\u003e\u003cp\u003e  The \u003cstrong\u003eWeir-type\u003c\/strong\u003e diaphragm valve (raised weir) has a central protrusion in the body — the weir — against which the diaphragm rests when closing. The fluid passes beneath the weir and to the sides in the open position, generating a smooth, non-turbulent flow. Specific advantages of the Weir type:\u003c\/p\u003e\u003cul\u003e  \u003cli\u003e\n\u003cstrong\u003eLaminar flow without turbulence:\u003c\/strong\u003e The flow profile does not generate cavitation or erosion in the diaphragm — significantly extends the service life of the diaphragm compared to through-way designs that generate direct turbulence on the diaphragm.\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eShort diaphragm stroke:\u003c\/strong\u003e The diaphragm travels a short distance between open and closed positions — less material fatigue from flexing cycles.\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eNo significant dead zones:\u003c\/strong\u003e The Weir-type body has less residual fluid accumulation than the through-way type — advantageous for fluids that crystallize or solidify upon cooling.\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eSuitable for modulating control:\u003c\/strong\u003e The Weir's flow characteristic is approximately linear — the diaphragm can be positioned at any point between open and closed to regulate flow.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eValve components — complete material table\u003c\/h3\u003e\u003ctable\u003e  \u003cthead\u003e    \u003ctr\u003e      \u003cth\u003eNo.\u003c\/th\u003e      \u003cth\u003eComponent\u003c\/th\u003e      \u003cth\u003eMaterial\u003c\/th\u003e      \u003cth\u003eContact with fluid\u003c\/th\u003e    \u003c\/tr\u003e  \u003c\/thead\u003e  \u003ctbody\u003e    \u003ctr\u003e      \u003ctd\u003e1\u003c\/td\u003e      \u003ctd\u003eLocking screw\u003c\/td\u003e      \u003ctd\u003eA320 B8\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e2\u003c\/td\u003e      \u003ctd\u003eBody bolt\u003c\/td\u003e      \u003ctd\u003eA320 B8\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e3\u003c\/td\u003e      \u003ctd\u003eHandwheel\u003c\/td\u003e      \u003ctd\u003eA216 WCB\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e4\u003c\/td\u003e      \u003ctd\u003eSleeve\u003c\/td\u003e      \u003ctd\u003eSS304\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e5\u003c\/td\u003e      \u003ctd\u003eBonnet\u003c\/td\u003e      \u003ctd\u003eA216 WCB\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e6\u003c\/td\u003e      \u003ctd\u003eStem nut\u003c\/td\u003e      \u003ctd\u003eBrass\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e7\u003c\/td\u003e      \u003ctd\u003eStem\u003c\/td\u003e      \u003ctd\u003eSS420\u003c\/td\u003e      \u003ctd\u003eNo — does not penetrate the fluid space\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e8\u003c\/td\u003e      \u003ctd\u003eAdjustable pad\u003c\/td\u003e      \u003ctd\u003eSS304\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e9\u003c\/td\u003e      \u003ctd\u003eCompressor (Disc)\u003c\/td\u003e      \u003ctd\u003eA216 WCB\u003c\/td\u003e      \u003ctd\u003eNo — pushes the diaphragm from the outside\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e10\u003c\/td\u003e      \u003ctd\u003eRubber diaphragm\u003c\/td\u003e      \u003ctd\u003eEPDM\u003c\/td\u003e      \u003ctd\u003eOuter face — mechanical support\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e11\u003c\/td\u003e      \u003ctd\u003eDiaphragm\u003c\/td\u003e      \u003ctd\u003ePFA \/ FEP\u003c\/td\u003e      \u003ctd\u003e✅ Inner face — sole contact with aggressive fluid\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e12\u003c\/td\u003e      \u003ctd\u003eBody\u003c\/td\u003e      \u003ctd\u003eA216 WCB + PFA Lining\u003c\/td\u003e      \u003ctd\u003e✅ Yes — PFA lined\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e13\u003c\/td\u003e      \u003ctd\u003eNut\u003c\/td\u003e      \u003ctd\u003eA194 2H\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e14\u003c\/td\u003e      \u003ctd\u003eFlat washer\u003c\/td\u003e      \u003ctd\u003e1045\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e    \u003ctr\u003e      \u003ctd\u003e15\u003c\/td\u003e      \u003ctd\u003eExternal hex screw\u003c\/td\u003e      \u003ctd\u003eA193 B7\u003c\/td\u003e      \u003ctd\u003eNo\u003c\/td\u003e    \u003c\/tr\u003e  \u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003cul\u003e  \u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Weir Diaphragm (raised weir)\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eDesign standard:\u003c\/strong\u003e MSS-SP-88\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eFace to face:\u003c\/strong\u003e EN 558-1\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eFlanges:\u003c\/strong\u003e ASME\/ANSI B16.5 — ANSI 150 RF\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eInspection and testing:\u003c\/strong\u003e API 598\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eBody material:\u003c\/strong\u003e A216 WCB + PFA interior lining\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eDiaphragm:\u003c\/strong\u003e PFA\/FEP (inner face) + EPDM (support)\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eStem:\u003c\/strong\u003e SS420 — does not penetrate the fluid space\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eNominal diameters:\u003c\/strong\u003e ½\" (DN15), ¾\" (DN20), 1\" (DN25), 1¼\" (DN32), 1½\" (DN40), 2\" (DN50), 2½\" (DN65), 3\" (DN80), 4\" (DN100)\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eMaximum pressure:\u003c\/strong\u003e 285–290 psi (19.6–20 bar) at 38 °C — reduces with temperature according to ASME B16.34\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eOperating temperature:\u003c\/strong\u003e -30 °C to +200 °C — verify specific fluid concentration and temperature\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eFlow characteristic:\u003c\/strong\u003e 1Cv = 1.167Kv — approximately linear flow characteristic\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eStandard operation:\u003c\/strong\u003e Manual with ergonomic handwheel\u003c\/li\u003e  \u003cli\u003e\n\u003cstrong\u003eVacuum capability:\u003c\/strong\u003e Yes — suitable for vacuum service\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eChemical compatibility confirmed in technical sheet\u003c\/h3\u003e\u003cul\u003e  \u003cli\u003e✅ Hydrochloric acid HCl — any concentration\u003c\/li\u003e  \u003cli\u003e✅ Nitric acid HNO₃ — including concentrated\u003c\/li\u003e  \u003cli\u003e✅ Hydrofluoric acid HF — any concentration\u003c\/li\u003e  \u003cli\u003e✅ Liquid chlorine Cl₂\u003c\/li\u003e  \u003cli\u003e✅ Sulfuric acid H₂SO₄ — including concentrated\u003c\/li\u003e  \u003cli\u003e✅ Sodium hypochlorite NaClO — any concentration\u003c\/li\u003e  \u003cli\u003e✅ Peroxides (H₂O₂ and other oxidizers)\u003c\/li\u003e  \u003cli\u003e✅ Concentrated alkalis (NaOH, KOH)\u003c\/li\u003e  \u003cli\u003e✅ Highly aggressive organic solvents\u003c\/li\u003e  \u003cli\u003e✅ Extremely high purity fluids — no metal leaching\u003c\/li\u003e  \u003cli\u003e⚠️ Always verify specific process concentration and temperature — compatibility may vary under extreme conditions\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eMain applications\u003c\/h3\u003e\u003cul\u003e  \u003cli\u003e    \u003cstrong\u003eChemical and petrochemical industry — concentrated acids:\u003c\/strong\u003e Isolation and flow control in lines for HF, concentrated H₂SO₄, concentrated HCl, HNO₃, and their mixtures. The absence of a stem in the fluid eliminates the most frequent leak point in process valves with extreme corrosive fluids.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eChlorine, hypochlorite, and oxidizer processes:\u003c\/strong\u003e Distribution of liquid chlorine, high-concentration sodium hypochlorite, and peroxides in water treatment plants, paper bleaching, and chemical synthesis. The PFA diaphragm resists the aggressive oxidation of these fluids indefinitely.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003ePharmaceutical industry — high purity:\u003c\/strong\u003e Control of synthesis fluids, process solvents, and acidic solutions in pharmaceutical plants where metallic fluid contamination is unacceptable. PFA has practically zero leaching — it does not release any compounds into the fluid.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eSemiconductors and ultrapure water (UPW):\u003c\/strong\u003e Control of etching acid mixtures, ultrapure water distribution, and process fluids in integrated circuit and flat panel display manufacturing. PFA is the standard material in the semiconductor industry due to its purity and chemical resistance.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eMining — SX-EW and acid leaching:\u003c\/strong\u003e Control of concentrated H₂SO₄ electrolyte in copper electrowinning cells, acid leaching solutions, and flotation reagents. The PFA diaphragm valve resists aggressive electrolyte better than any valve with an exposed metallic stem.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eWater treatment — ClO₂ and chlorine disinfection:\u003c\/strong\u003e Control of chlorine dioxide, dissolved gaseous chlorine, and hypochlorite in water treatment plants using these disinfectants. PFA resists concentrations that would destroy SS316 in weeks.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eCrystallizing or sticky fluids:\u003c\/strong\u003e The smooth PFA inner lining prevents the adhesion of crystals and solids that would accumulate in the cavities of a ball or butterfly valve — facilitating cleaning and preventing valve blockage.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003ePaper, ink, pigment, and coating manufacturing:\u003c\/strong\u003e Control of bleaching solutions, acidic pigments, and aggressive solvent coatings where the smooth PFA surface prevents scaling and simplifies cleaning between batches.  \u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eDiaphragm valve automation\u003c\/h3\u003e\u003cp\u003e  The standard version includes manual operation with an ergonomic handwheel. For automation, the diaphragm valve is compatible with linear pneumatic actuators that replace the handwheel — the actuator pushes and releases the diaphragm with the same linear action as the manual handwheel. Specific considerations:\u003c\/p\u003e\u003cul\u003e  \u003cli\u003e    \u003cstrong\u003eNC linear pneumatic actuator:\u003c\/strong\u003e For hazardous fluids (HF, ClO₂, concentrated H₂SO₄), automatic spring closure upon air supply loss is the safety standard. The single-acting NC linear pneumatic actuator is the most common configuration.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eModulating control:\u003c\/strong\u003e The Weir's linear flow characteristic allows proportional flow control with a 4–20 mA electropneumatic positioner — the diaphragm valve is suitable for PID control loops in corrosive fluids where a globe valve would have chemical compatibility issues.  \u003c\/li\u003e  \u003cli\u003e    \u003cstrong\u003eActuator material in acidic vapors:\u003c\/strong\u003e Specify an actuator with an SS316 casing or a high chemical resistance epoxy coating — standard anodized aluminum would corrode in environments with HF or HCl vapors.  \u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e  For the complete range of corrosion-resistant valves, see \u003ca href=\"\/en\/collections\/valvulas-de-bola-anticorrosivas-interiores-de-pfa\"\u003ePFA corrosion-resistant valves category →\u003c\/a\u003e\u003c\/p\u003e\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e \u003c\/p\u003e\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0555\/3917\/1508\/files\/valvula-de-diafragma-ansi-150-wcb-interior_pfa-pbfl.pdf?v=1777492808\" title=\"Ficha Técnica de Diafragma Anticorrosiva Recubrimiento Interior PFA Cematic\" rel=\"noopener\" target=\"_blank\"\u003e\u003cspan style=\"color: #ab2929;\"\u003e\u003cstrong\u003eTechnical Data Sheet\u003c\/strong\u003e\u003c\/span\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"Cematic","offers":[{"title":"1\/2\"","offer_id":51323172094265,"sku":"PDFL102","price":6276.9,"currency_code":"MXN","in_stock":true},{"title":"1\"","offer_id":51323172127033,"sku":"PDFL106","price":7621.95,"currency_code":"MXN","in_stock":true},{"title":"1-1\/2\"","offer_id":51323172159801,"sku":"PDFL108","price":10760.4,"currency_code":"MXN","in_stock":true},{"title":"2\"","offer_id":51323172192569,"sku":"PDFL110","price":13002.15,"currency_code":"MXN","in_stock":true},{"title":"2-1\/2\"","offer_id":51323172225337,"sku":"PDFL112","price":18830.7,"currency_code":"MXN","in_stock":true},{"title":"3\"","offer_id":51323172258105,"sku":"PDFL114","price":27349.35,"currency_code":"MXN","in_stock":true},{"title":"4\"","offer_id":51323172290873,"sku":"PDFL118","price":32729.55,"currency_code":"MXN","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0555\/3917\/1508\/files\/valvula-anticorrosiva-diafragma-pfa.jpg?v=1776461126","url":"https:\/\/cematic.com.mx\/en\/products\/valvula-diafragma-anticorrosiva-pfa-wcb-ansi-150","provider":"Cematic","version":"1.0","type":"link"}