{"product_id":"valvula-cuchilla-wcb-asiento-epdm-150lb","title":"WCB Knife Gate Valve | EPDM Seat | Bidirectional | Manual | 2\" to 12\"","description":"\u003ch2\u003eWCB Knife Gate Valve with EPDM Seat — Bidirectional, Ultrathin Body, 2\" to 12\"\u003c\/h2\u003e\n\n\u003cp\u003e\n  The \u003cstrong\u003eWCB knife gate valve with EPDM seat\u003c\/strong\u003e is the most abrasion-resistant variant of the Cematic knife gate family — its internal EPDM rubber lining protects all internal metal surfaces against erosion from solid particles, tailings, and abrasive slurries that would directly wear down metal in unlined versions. Unlike unidirectional knife gates, this model is \u003cstrong\u003ebidirectional\u003c\/strong\u003e — the blade seals tightly in both flow directions, simplifying installation by eliminating the risk of mounting the valve in the wrong direction. The ultrathin two-piece wafer body design is more compact than high-yoke designs — an advantage in installations with limited axial space between equipment.\n\u003c\/p\u003e\n\n\u003ch3\u003eThe EPDM seat — elastic protection against abrasive particles\u003c\/h3\u003e\n\u003cp\u003e\n  The EPDM seat in a knife gate valve serves a different function than the PTFE or metal seats of previous versions:\n\u003c\/p\u003e\n\u003cul\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eElastic protective lining:\u003c\/strong\u003e EPDM is not just the sealing element — it lines the contact area between the blade and the body, absorbing the impact of abrasive particles traveling in the flow. Instead of hard particles directly hitting the metal of the seat, they first impact the EPDM elastomer, which absorbs and distributes the impact energy.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eBidirectional sealing:\u003c\/strong\u003e The elasticity of EPDM allows the seat to adapt to micro-irregularities on both faces of the blade surface — providing tight sealing regardless of pressure direction. Rigid PTFE requires a more precise seat geometry to seal in both directions.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eSelf-cleaning by elasticity:\u003c\/strong\u003e Elastic EPDM tends to expel solid particles lodged between the seat and the blade during opening and closing movements — the elastic deformation of the seat as the blade passes pushes particles out of the sealing area.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eOperating temperature up to 110 °C:\u003c\/strong\u003e EPDM is the correct material for hot water, moderate-temperature process slurries, and aqueous fluids up to 110 °C. Above this limit, versions with PTFE or metal seats (up to 180 °C) are the correct specification.\n  \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3\u003eBidirectional — simplifies installation and specification\u003c\/h3\u003e\n\u003cp\u003e\n  Unidirectional knife gate valves have a flow direction indicated on the body and must be installed correctly to seal. The bidirectional valve eliminates this restriction:\n\u003c\/p\u003e\n\u003cul\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eNo critical flow direction:\u003c\/strong\u003e The valve seals in both directions — the installer does not need to check flow orientation before mounting the valve.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eProtection against back pressure:\u003c\/strong\u003e In lines where pressure can exist in both directions (pumping systems with potential for reversal, bidirectional bypasses), the bidirectional valve seals correctly in any scenario.\n  \u003c\/li\u003e\n\u003cli\u003e\n\n\u003cstrong\u003eSimpler specification:\u003c\/strong\u003e By not requiring flow direction indication, the technical specification of the project is simpler, and the risk of installation errors in the field is eliminated.\n  \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3\u003eUltrathin two-piece body\u003c\/h3\u003e\n\u003cp\u003e\n  The ultrathin body design (minimum face-to-face according to dimension table) with two-piece construction differentiates this valve from the conventional high-yoke design:\n\u003c\/p\u003e\n\u003cul\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eSmaller axial space:\u003c\/strong\u003e The 58–90 mm face-to-face (depending on diameter) is significantly smaller than that of high-yoke knife gates — a more compact valve that takes up less space in the line.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eLower weight:\u003c\/strong\u003e Without a tall structural yoke, the valve weighs considerably less than versions with a yoke — an advantage in aerial installations and structures with load limitations.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eInstallation between standard flanges:\u003c\/strong\u003e The ultrathin profile allows installation in spaces where high-yoke knife gates would not fit.\n  \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3\u003eValve Components\u003c\/h3\u003e\n\u003ctable\u003e\n\n  \u003cthead\u003e\n\n    \u003ctr\u003e\n\n      \u003cth\u003eNo.\u003c\/th\u003e\n\n      \u003cth\u003eComponent\u003c\/th\u003e\n\n      \u003cth\u003eMaterial\u003c\/th\u003e\n\n    \u003c\/tr\u003e\n\n  \u003c\/thead\u003e\n\n  \u003ctbody\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e1\u003c\/td\u003e\n\n      \u003ctd\u003eCover\u003c\/td\u003e\n\n      \u003ctd\u003eCarbon Steel\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e2\u003c\/td\u003e\n\n      \u003ctd\u003eBolt\u003c\/td\u003e\n\n      \u003ctd\u003eB7\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e3\u003c\/td\u003e\n\n      \u003ctd\u003eGasket\u003c\/td\u003e\n\n      \u003ctd\u003eEPDM\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e4\u003c\/td\u003e\n\n      \u003ctd\u003eBody\u003c\/td\u003e\n\n      \u003ctd\u003eWCB\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e5\u003c\/td\u003e\n\n      \u003ctd\u003eSeat\u003c\/td\u003e\n\n      \u003ctd\u003eEPDM\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e6\u003c\/td\u003e\n\n      \u003ctd\u003eDisk (Blade)\u003c\/td\u003e\n\n      \u003ctd\u003eSS304\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e7\u003c\/td\u003e\n\n      \u003ctd\u003ePacking\u003c\/td\u003e\n\n      \u003ctd\u003eEPDM\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e8\u003c\/td\u003e\n\n      \u003ctd\u003eGland\u003c\/td\u003e\n\n      \u003ctd\u003eWCB\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e9\u003c\/td\u003e\n\n      \u003ctd\u003eStem\u003c\/td\u003e\n\n      \u003ctd\u003e2Cr13 (Martensitic Stainless Steel)\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e10\u003c\/td\u003e\n\n      \u003ctd\u003ePlate\u003c\/td\u003e\n\n      \u003ctd\u003eCarbon Steel\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e11\u003c\/td\u003e\n\n      \u003ctd\u003eConnection Disk\u003c\/td\u003e\n\n      \u003ctd\u003eWCB\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e12\u003c\/td\u003e\n\n      \u003ctd\u003eYoke Bushing\u003c\/td\u003e\n\n      \u003ctd\u003eCopper Alloy\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e13\u003c\/td\u003e\n\n      \u003ctd\u003eBearing\u003c\/td\u003e\n\n      \u003ctd\u003eGCr15\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003e14\u003c\/td\u003e\n\n      \u003ctd\u003eHandwheel\u003c\/td\u003e\n\n      \u003ctd\u003eMalleable Cast Iron\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n  \u003c\/tbody\u003e\n\n\n\u003c\/table\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eType:\u003c\/strong\u003e Bidirectional Knife Gate — vertical linear motion\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eBody Design:\u003c\/strong\u003e Two-piece, ultrathin\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eInstallation:\u003c\/strong\u003e Between flanges — Class 150LB\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eBody Material:\u003c\/strong\u003e WCB (ASTM A216 Gr. WCB)\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eDisk (Blade):\u003c\/strong\u003e SS304\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eSeat:\u003c\/strong\u003e EPDM\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eGasket:\u003c\/strong\u003e EPDM\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003ePacking:\u003c\/strong\u003e EPDM\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eStem:\u003c\/strong\u003e 2Cr13 (Martensitic Stainless Steel)\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eOperation:\u003c\/strong\u003e Manual with malleable cast iron handwheel\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eNominal Diameters:\u003c\/strong\u003e 2\" (DN50), 3\" (DN80), 4\" (DN100), 6\" (DN150), 8\" (DN200), 10\" (DN250), 12\" (DN300)\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eMaximum Pressure:\u003c\/strong\u003e 290 psi (20 bar) at 38 °C — reduced with temperature according to ASME B16.34\/B16.5\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eSeat Test Pressure:\u003c\/strong\u003e 0.8 MPa (8 bar)\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eOperating Temperature:\u003c\/strong\u003e -20 °C to +110 °C\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n\u003cstrong\u003eFlow Direction:\u003c\/strong\u003e Bidirectional\n  \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3\u003eComparison — Four Cematic Knife Gates\u003c\/h3\u003e\n\u003ctable\u003e\n\n  \u003cthead\u003e\n\n    \u003ctr\u003e\n\n      \u003cth\u003eCriterion\u003c\/th\u003e\n\n      \u003cth\u003eWCB + EPDM ← This\u003c\/th\u003e\n\n      \u003cth\u003eWCB + Viton (Pneumatic)\u003c\/th\u003e\n\n      \u003cth\u003eSS316 (Pneumatic)\u003c\/th\u003e\n\n      \u003cth\u003eSS316 (Manual)\u003c\/th\u003e\n\n    \u003c\/tr\u003e\n\n  \u003c\/thead\u003e\n\n  \u003ctbody\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eBody\u003c\/td\u003e\n\n      \u003ctd\u003eWCB\u003c\/td\u003e\n\n      \u003ctd\u003eWCB\u003c\/td\u003e\n\n      \u003ctd\u003eCF8M (SS316)\u003c\/td\u003e\n\n      \u003ctd\u003eCF8M (SS316)\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eBlade\u003c\/td\u003e\n\n      \u003ctd\u003eSS304\u003c\/td\u003e\n\n      \u003ctd\u003eSS304\u003c\/td\u003e\n\n      \u003ctd\u003eSS316L\u003c\/td\u003e\n\n      \u003ctd\u003eSS316L\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eSeat\u003c\/td\u003e\n\n      \u003ctd\u003eEPDM — elastic, protective\u003c\/td\u003e\n\n      \u003ctd\u003eViton — elastic, HC resistant\u003c\/td\u003e\n\n      \u003ctd\u003ePTFE or metallic\u003c\/td\u003e\n\n      \u003ctd\u003ePTFE or metallic\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eFlow Direction\u003c\/td\u003e\n\n      \u003ctd\u003e✅ Bidirectional\u003c\/td\u003e\n\n      \u003ctd\u003eUnidirectional\u003c\/td\u003e\n\n      \u003ctd\u003eUnidirectional\u003c\/td\u003e\n\n      \u003ctd\u003eUnidirectional\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eMaximum Temperature\u003c\/td\u003e\n\n      \u003ctd\u003e110 °C\u003c\/td\u003e\n\n      \u003ctd\u003e180 °C\u003c\/td\u003e\n\n      \u003ctd\u003e180 °C\u003c\/td\u003e\n\n      \u003ctd\u003e180 °C\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eActuator\u003c\/td\u003e\n\n      \u003ctd\u003e✅ Manual — handwheel included\u003c\/td\u003e\n\n      \u003ctd\u003eDouble-acting pneumatic\u003c\/td\u003e\n\n      \u003ctd\u003eDouble-acting pneumatic\u003c\/td\u003e\n\n      \u003ctd\u003e✅ Manual — handwheel included\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eBody Design\u003c\/td\u003e\n\n      \u003ctd\u003e✅ Ultrathin — more compact\u003c\/td\u003e\n\n      \u003ctd\u003eWith yoke\u003c\/td\u003e\n\n      \u003ctd\u003eWith yoke\u003c\/td\u003e\n\n      \u003ctd\u003eWith yoke\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eDiameters\u003c\/td\u003e\n\n      \u003ctd\u003e2\" to 12\"\u003c\/td\u003e\n\n      \u003ctd\u003e2\" to 18\"\u003c\/td\u003e\n\n      \u003ctd\u003e2\" to 18\"\u003c\/td\u003e\n\n      \u003ctd\u003e2\" to 18\"\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n    \u003ctr\u003e\n\n      \u003ctd\u003eFirst choice for\u003c\/td\u003e\n\n      \u003ctd\u003e✅ Abrasive mining, ash, cement, slurries with hard particles\u003c\/td\u003e\n\n      \u003ctd\u003eWWTP without corrosivity, municipal sludges\u003c\/td\u003e\n\n      \u003ctd\u003eCorrosive sludges, H₂S, aggressive industrial processes\u003c\/td\u003e\n\n      \u003ctd\u003eOccasional isolation in corrosive sludges\u003c\/td\u003e\n\n    \u003c\/tr\u003e\n\n  \u003c\/tbody\u003e\n\n\n\u003c\/table\u003e\n\n\u003ch3\u003eFluid Compatibility\u003c\/h3\u003e\n\u003cul\u003e\n\n  \u003cli\u003e✅ Non-corrosive municipal and industrial wastewater\n  \u003c\/li\u003e\n\n  \u003cli\u003e✅ Primary and secondary WWTP sludges\n  \u003c\/li\u003e\n\n  \u003cli\u003e✅ Mineral tailings and abrasive slurries\n  \u003c\/li\u003e\n\n  \u003cli\u003e✅ Fly ash and limestone slurries in thermal power plants\n  \u003c\/li\u003e\n\n  \u003cli\u003e✅ Cement, clinker, and slag mixtures in the cement industry\n  \u003c\/li\u003e\n\n  \u003cli\u003e✅ Viscous fluids with non-corrosive suspended solids\n  \u003c\/li\u003e\n\n  \u003cli\u003e✅ Anaerobic digestion sludges up to 55 °C\n  \u003c\/li\u003e\n\n  \u003cli\u003e⚠️ Fluids with high chlorides or H₂S: WCB body may corrode — use SS316\n  \u003c\/li\u003e\n\n  \u003cli\u003e⚠️ Temperature above 110 °C: use knife gate with PTFE or metal seat\n  \u003c\/li\u003e\n\n  \u003cli\u003e❌ Corrosive fluids (acids, alkalis): use SS316 or PFA anti-corrosive knife gate\n  \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003ch3\u003eMain Applications\u003c\/h3\u003e\n\u003cul\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eMining — abrasive tailings and slurries:\u003c\/strong\u003e The most demanding application for any knife gate valve. Mineral tailings (30–70% solids, quartz, silica, and hard mineral particles) rapidly erode bare metal. The EPDM lining absorbs abrasive impacts and extends the lifespan of internal surfaces. The bidirectional nature is particularly valuable in tailings circuits where flow direction can vary depending on pump operation.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eThermal power plants — ash and desulfurization slurries:\u003c\/strong\u003e Hydraulic transport of fly ash, limestone slurries (FGD), and slag suspensions are the most abrasive fluids in the energy industry. The EPDM of the seat protects the metal parts of the WCB from the continuous impact of fine ash and slag particles.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eCement industry:\u003c\/strong\u003e Flow control of cement mixtures, clinker slurries, and slag in cement production facilities. The abrasiveness of these mixtures requires elastomeric protection of the seat — EPDM is the standard material for these services.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eWastewater treatment plants — municipal sludges:\u003c\/strong\u003e Isolation of primary, secondary, and digested sludge lines in municipal WWTPs. Bidirectionality simplifies project installation and specification — no risk of incorrect mounting.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003ePulp and paper — pulp and sludge lines:\u003c\/strong\u003e Flow control of cellulose pulp and process sludges in paper mills. The high abrasion resistance of EPDM significantly extends the lifespan of the seat against fibers and particles in the pulp.\n  \u003c\/li\u003e\n\n  \u003cli\u003e\n\n    \u003cstrong\u003eChemical processes with non-corrosive solids:\u003c\/strong\u003e Process fluids with suspended particles where the fluid's corrosivity does not exceed WCB's resistance — solid catalysts, pigments, process additives, and reactant mixtures with solids.\n  \u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cp\u003e\n  For sludges with higher chemical aggressiveness, see \u003ca href=\"\/products\/valvula-cuchilla-ss316-lug-manual\"\u003eSS316 knife gate valve →\u003c\/a\u003e\n\u003c\/p\u003e\n\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0555\/3917\/1508\/files\/valvula-de-cuchilla-asiento-epdm-cuerpo-wcb-150.pdf?v=1761777302\" title=\"Ficha Técnica de Válvula de Cuchilla Cuerpo WCB Asiento EPDM Cematic\" rel=\"noopener\" target=\"_blank\"\u003e\u003cspan style=\"color: #b42c2c;\"\u003e\u003cstrong\u003eTechnical Data Sheet\u003c\/strong\u003e\u003c\/span\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"Cematic","offers":[{"title":"2\"","offer_id":51299176677689,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true},{"title":"3\"","offer_id":51299176710457,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true},{"title":"4\"","offer_id":51299176743225,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true},{"title":"6\"","offer_id":51299176775993,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true},{"title":"8\"","offer_id":51299176808761,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true},{"title":"10\"","offer_id":51299176841529,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true},{"title":"12\"","offer_id":51299176874297,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true},{"title":"14\"","offer_id":51299176907065,"sku":null,"price":0.0,"currency_code":"USD","in_stock":false},{"title":"16\"","offer_id":51299176939833,"sku":null,"price":0.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0555\/3917\/1508\/files\/V_lvula_de_cuchilla_WCB_asiento_EPDM_con_bridas_150LB_y_accionamiento_manual.jpg?v=1774309531","url":"https:\/\/cematic.com\/products\/valvula-cuchilla-wcb-asiento-epdm-150lb","provider":"Cematic","version":"1.0","type":"link"}