{"id":284,"date":"2026-09-08T06:03:58","date_gmt":"2026-09-08T06:03:58","guid":{"rendered":"https:\/\/wdlvalve.com\/?post_type=product&p=284"},"modified":"2026-09-18T01:59:59","modified_gmt":"2026-09-18T01:59:59","slug":"%e0%b8%a7%e0%b8%b2%e0%b8%a5%e0%b9%8c%e0%b8%a7%e0%b8%95%e0%b8%a3%e0%b8%a7%e0%b8%88%e0%b8%aa%e0%b8%ad%e0%b8%9a%e0%b9%81%e0%b8%9a%e0%b8%9a%e0%b8%aa%e0%b8%a7%e0%b8%b4%e0%b8%87-api-6d","status":"publish","type":"product","link":"https:\/\/wdlvalve.com\/th\/product\/%e0%b8%a7%e0%b8%b2%e0%b8%a5%e0%b9%8c%e0%b8%a7%e0%b8%95%e0%b8%a3%e0%b8%a7%e0%b8%88%e0%b8%aa%e0%b8%ad%e0%b8%9a%e0%b9%81%e0%b8%9a%e0%b8%9a%e0%b8%aa%e0%b8%a7%e0%b8%b4%e0%b8%87-api-6d\/","title":{"rendered":"\u0e27\u0e32\u0e25\u0e4c\u0e27\u0e40\u0e0a\u0e47\u0e01\u0e41\u0e1a\u0e1a\u0e2a\u0e27\u0e34\u0e07\u0e21\u0e35\u0e2b\u0e19\u0e49\u0e32\u0e41\u0e1b\u0e25\u0e19 API 6D \/ BS 1868 \u0e04\u0e25\u0e32\u0e2a 150\u20131500"},"content":{"rendered":"
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\n

API 6D \/ BS 1868 Flanged Swing Check Valve<\/h2>\n

The \u0e27\u0e32\u0e25\u0e4c\u0e27\u0e15\u0e23\u0e27\u0e08\u0e2a\u0e2d\u0e1a\u0e41\u0e1a\u0e1a\u0e2a\u0e27\u0e34\u0e07 WDL API 6D<\/strong> is designed to allow flow in one direction and automatically prevent reverse flow when the upstream pressure decreases. It protects pumps, compressors and other pipeline equipment from backflow and pressure reversal.<\/p>\n

The valve features a swing-type disc and a straight-through flow passage for low flow resistance. Depending on the selected design and flow direction, it can be installed in horizontal piping or vertical piping with upward flow.<\/p>\n<\/div>\n

Design Features<\/h2>\n
    \n
  • Swing-type disc provides automatic non-return operation.<\/li>\n
  • Straight-through flow passage helps reduce pressure loss.<\/li>\n
  • Internal hinge pin construction reduces potential external leakage points.<\/li>\n
  • Bolted cover construction provides convenient inspection and maintenance.<\/li>\n
  • Pressure-seal cover construction is available for Class 900 and higher-pressure configurations.<\/li>\n
  • Renewable or welded seat surfaces are available according to material and service requirements.<\/li>\n
  • RF, RTJ and butt-weld end connections can be supplied.<\/li>\n
  • Carbon steel, stainless steel and special-alloy materials are available.<\/li>\n<\/ul>\n

    \u0e21\u0e32\u0e15\u0e23\u0e10\u0e32\u0e19\u0e17\u0e35\u0e48\u0e43\u0e0a\u0e49<\/h2>\n
    \n\n\n\n\n\n\n\n\n\n\n
    \u0e23\u0e32\u0e22\u0e01\u0e32\u0e23<\/th>\nApplicable Standard<\/th>\n<\/tr>\n<\/thead>\n
    Design and Manufacture<\/td>\nAPI 6D, BS 1868 \u0e41\u0e25\u0e30 ASME B16.34<\/td>\n<\/tr>\n
    Face-to-Face Dimensions<\/td>\nASME B16.10<\/td>\n<\/tr>\n
    Flange Dimensions<\/td>\nASME B16.5 \/ ASME B16.47 where applicable<\/td>\n<\/tr>\n
    Butt-Weld Ends<\/td>\nASME B16.25<\/td>\n<\/tr>\n
    Pressure-Temperature Rating<\/td>\nASME B16.34<\/td>\n<\/tr>\n
    Inspection and Testing<\/td>\nAPI 598<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Pressure Test Data<\/h2>\n
    \n\n\n\n\n\n\n\n\n\n
    Pressure Class<\/th>\nShell Test<\/th>\nWater Seat Test<\/th>\nAir Seat Test<\/th>\n<\/tr>\n
    MPa<\/th>\npsi<\/th>\nMPa<\/th>\npsi<\/th>\nMPa<\/th>\npsi<\/th>\n<\/tr>\n<\/thead>\n
    Class 150<\/td>\n3.1<\/td>\n450<\/td>\n2.2<\/td>\n315<\/td>\n0.5\u20130.7<\/td>\n60\u2013100<\/td>\n<\/tr>\n
    Class 300<\/td>\n7.8<\/td>\n1125<\/td>\n5.6<\/td>\n815<\/td>\n<\/tr>\n
    Class 600<\/td>\n15.3<\/td>\n2225<\/td>\n11.2<\/td>\n1630<\/td>\n<\/tr>\n
    Class 900<\/td>\n23.1<\/td>\n3350<\/td>\n16.8<\/td>\n2440<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    \u0e27\u0e31\u0e2a\u0e14\u0e38\u0e17\u0e35\u0e48\u0e21\u0e35\u0e2d\u0e22\u0e39\u0e48<\/h2>\n
    \n\n\n\n\n\n\n\n\n\n
    \u0e2a\u0e48\u0e27\u0e19\u0e1b\u0e23\u0e30\u0e01\u0e2d\u0e1a<\/th>\n\u0e27\u0e31\u0e2a\u0e14\u0e38\u0e17\u0e35\u0e48\u0e21\u0e35\u0e2d\u0e22\u0e39\u0e48<\/th>\n<\/tr>\n<\/thead>\n
    Body and Cover<\/td>\nASTM A216 WCB, ASTM A351 CF8, CF8M, CF3 and CF3M<\/td>\n<\/tr>\n
    Disc and Hinge<\/td>\nWCB, CF8, CF8M, CF3, CF3M or Monel<\/td>\n<\/tr>\n
    Hinge Pin<\/td>\nF6a, F304, F304L, F316, F316L or Monel<\/td>\n<\/tr>\n
    Disc Seating Surface<\/td>\n13Cr, 304, 304L, 316, 316L, Stellite or Monel<\/td>\n<\/tr>\n
    Body Seat Surface<\/td>\n13Cr, 304, 304L, 316, 316L, Stellite or Monel<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    The final body, trim and seating materials should be selected according to the medium, chloride concentration, operating temperature, pressure and corrosion conditions.<\/p>\n

    Class 150 Main Dimensions<\/h2>\n
    \n\n\n\n\n\n\n
    NPS<\/th>\n2″<\/td>\n2-1\/2″<\/td>\n3″<\/td>\n4″<\/td>\n5″<\/td>\n6″<\/td>\n8″<\/td>\n10″<\/td>\n12″<\/td>\n14″<\/td>\n16″<\/td>\n18″<\/td>\n20″<\/td>\n24″<\/td>\n<\/tr>\n
    DN<\/th>\n50<\/td>\n65<\/td>\n80<\/td>\n100<\/td>\n125<\/td>\n150<\/td>\n200<\/td>\n250<\/td>\n300<\/td>\n350<\/td>\n400<\/td>\n450<\/td>\n500<\/td>\n600<\/td>\n<\/tr>\n
    L (mm)<\/th>\n203<\/td>\n216<\/td>\n241<\/td>\n292<\/td>\n330<\/td>\n356<\/td>\n495<\/td>\n622<\/td>\n699<\/td>\n787<\/td>\n864<\/td>\n978<\/td>\n978<\/td>\n1275<\/td>\n<\/tr>\n
    H (mm)<\/th>\n142<\/td>\n166<\/td>\n178<\/td>\n236<\/td>\n252<\/td>\n266<\/td>\n314<\/td>\n368<\/td>\n429<\/td>\n455<\/td>\n410<\/td>\n560<\/td>\n600<\/td>\n880<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Class 300 Main Dimensions<\/h2>\n
    \n\n\n\n\n\n\n
    NPS<\/th>\n2″<\/td>\n2-1\/2″<\/td>\n3″<\/td>\n4″<\/td>\n5″<\/td>\n6″<\/td>\n8″<\/td>\n10″<\/td>\n12″<\/td>\n14″<\/td>\n16″<\/td>\n18″<\/td>\n20″<\/td>\n24″<\/td>\n<\/tr>\n
    DN<\/th>\n50<\/td>\n65<\/td>\n80<\/td>\n100<\/td>\n125<\/td>\n150<\/td>\n200<\/td>\n250<\/td>\n300<\/td>\n350<\/td>\n400<\/td>\n450<\/td>\n500<\/td>\n600<\/td>\n<\/tr>\n
    L (mm)<\/th>\n267<\/td>\n292<\/td>\n318<\/td>\n356<\/td>\n400<\/td>\n444<\/td>\n533<\/td>\n622<\/td>\n711<\/td>\n838<\/td>\n864<\/td>\n978<\/td>\n1016<\/td>\n1346<\/td>\n<\/tr>\n
    H (mm)<\/th>\n165<\/td>\n185<\/td>\n205<\/td>\n228<\/td>\n250<\/td>\n275<\/td>\n325<\/td>\n378<\/td>\n410<\/td>\n480<\/td>\n530<\/td>\n575<\/td>\n630<\/td>\n860<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Class 400 Main Dimensions<\/h2>\n
    \n\n\n\n\n\n\n
    NPS<\/th>\n2″<\/td>\n2-1\/2″<\/td>\n3″<\/td>\n4″<\/td>\n5″<\/td>\n6″<\/td>\n8″<\/td>\n10″<\/td>\n12″<\/td>\n14″<\/td>\n16″<\/td>\n18″<\/td>\n20″<\/td>\n<\/tr>\n
    DN<\/th>\n50<\/td>\n65<\/td>\n80<\/td>\n100<\/td>\n125<\/td>\n150<\/td>\n200<\/td>\n250<\/td>\n300<\/td>\n350<\/td>\n400<\/td>\n450<\/td>\n500<\/td>\n<\/tr>\n
    L (mm)<\/th>\n292<\/td>\n330<\/td>\n356<\/td>\n406<\/td>\n457<\/td>\n495<\/td>\n597<\/td>\n673<\/td>\n762<\/td>\n889<\/td>\n902<\/td>\n1016<\/td>\n1054<\/td>\n<\/tr>\n
    H (mm)<\/th>\n190<\/td>\n203<\/td>\n229<\/td>\n267<\/td>\n292<\/td>\n330<\/td>\n381<\/td>\n406<\/td>\n457<\/td>\n528<\/td>\n546<\/td>\n597<\/td>\n635<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Class 600 Main Dimensions<\/h2>\n
    \n\n\n\n\n\n\n
    NPS<\/th>\n2″<\/td>\n2-1\/2″<\/td>\n3″<\/td>\n4″<\/td>\n5″<\/td>\n6″<\/td>\n8″<\/td>\n10″<\/td>\n12″<\/td>\n14″<\/td>\n16″<\/td>\n18″<\/td>\n20″<\/td>\n24″<\/td>\n<\/tr>\n
    DN<\/th>\n50<\/td>\n65<\/td>\n80<\/td>\n100<\/td>\n125<\/td>\n150<\/td>\n200<\/td>\n250<\/td>\n300<\/td>\n350<\/td>\n400<\/td>\n450<\/td>\n500<\/td>\n600<\/td>\n<\/tr>\n
    L (mm)<\/th>\n292<\/td>\n330<\/td>\n356<\/td>\n432<\/td>\n508<\/td>\n559<\/td>\n660<\/td>\n787<\/td>\n838<\/td>\n889<\/td>\n991<\/td>\n1092<\/td>\n1194<\/td>\n1397<\/td>\n<\/tr>\n
    H (mm)<\/th>\n203<\/td>\n229<\/td>\n235<\/td>\n286<\/td>\n292<\/td>\n330<\/td>\n381<\/td>\n457<\/td>\n584<\/td>\n835<\/td>\n684<\/td>\n752<\/td>\n975<\/td>\n1111<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Class 900 Main Dimensions<\/h2>\n
    \n\n\n\n\n\n\n
    NPS<\/th>\n2″<\/td>\n2-1\/2″<\/td>\n3″<\/td>\n4″<\/td>\n5″<\/td>\n6″<\/td>\n8″<\/td>\n10″<\/td>\n12″<\/td>\n14″<\/td>\n16″<\/td>\n<\/tr>\n
    DN<\/th>\n50<\/td>\n65<\/td>\n80<\/td>\n100<\/td>\n125<\/td>\n150<\/td>\n200<\/td>\n250<\/td>\n300<\/td>\n350<\/td>\n400<\/td>\n<\/tr>\n
    L (mm)<\/th>\n368<\/td>\n419<\/td>\n381<\/td>\n457<\/td>\n559<\/td>\n610<\/td>\n737<\/td>\n838<\/td>\n965<\/td>\n1029<\/td>\n1130<\/td>\n<\/tr>\n
    H (mm)<\/th>\n216<\/td>\n254<\/td>\n292<\/td>\n318<\/td>\n343<\/td>\n368<\/td>\n432<\/td>\n546<\/td>\n660<\/td>\n782<\/td>\n838<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Class 1500 Main Dimensions<\/h2>\n
    \n\n\n\n\n\n\n
    NPS<\/th>\n2-1\/2″<\/td>\n3″<\/td>\n4″<\/td>\n5″<\/td>\n6″<\/td>\n8″<\/td>\n10″<\/td>\n12″<\/td>\n14″<\/td>\n16″<\/td>\n<\/tr>\n
    DN<\/th>\n65<\/td>\n80<\/td>\n100<\/td>\n125<\/td>\n150<\/td>\n200<\/td>\n250<\/td>\n300<\/td>\n350<\/td>\n400<\/td>\n<\/tr>\n
    L (mm)<\/th>\n419<\/td>\n470<\/td>\n546<\/td>\n673<\/td>\n705<\/td>\n832<\/td>\n991<\/td>\n1130<\/td>\n1257<\/td>\n1384<\/td>\n<\/tr>\n
    H (mm)<\/th>\n193<\/td>\n246<\/td>\n288<\/td>\n324<\/td>\n373<\/td>\n466<\/td>\n536<\/td>\n857<\/td>\n950<\/td>\n1020<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Dimension tables are for preliminary product selection. Final dimensions may vary with flange facing, end connection, body material, pressure-seal construction and customer requirements. Always refer to the approved WDL Valve drawing.<\/p>\n

    \u0e01\u0e32\u0e23\u0e43\u0e0a\u0e49\u0e07\u0e32\u0e19\u0e17\u0e31\u0e48\u0e27\u0e44\u0e1b<\/h2>\n
      \n
    • Oil and natural gas transmission pipelines<\/li>\n
    • Petroleum refining and petrochemical processing<\/li>\n
    • Chemical and fertilizer plants<\/li>\n
    • Power generation and steam systems<\/li>\n
    • Water treatment and industrial water systems<\/li>\n
    • Marine and offshore piping systems<\/li>\n
    • High-pressure and high-temperature process lines<\/li>\n<\/ul>\n

      Ordering Information<\/h2>\n

      When requesting a quotation, please provide the nominal size, pressure class, body material, trim material, flange facing, service medium, operating pressure, operating temperature and required inspection documents.<\/p>\n

      WDL Valve can supply material certificates, dimensional drawings and pressure test reports according to the agreed order requirements.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

      \u0e27\u0e32\u0e25\u0e4c\u0e27\u0e15\u0e23\u0e27\u0e08\u0e2a\u0e2d\u0e1a\u0e41\u0e1a\u0e1a\u0e2a\u0e27\u0e34\u0e07 WDL API 6D<\/strong> \u0e1b\u0e49\u0e2d\u0e07\u0e01\u0e31\u0e19\u0e01\u0e32\u0e23\u0e44\u0e2b\u0e25\u0e22\u0e49\u0e2d\u0e19\u0e01\u0e25\u0e31\u0e1a\u0e43\u0e19\u0e23\u0e30\u0e1a\u0e1a\u0e17\u0e48\u0e2d\u0e02\u0e2d\u0e07\u0e2d\u0e38\u0e15\u0e2a\u0e32\u0e2b\u0e01\u0e23\u0e23\u0e21\u0e19\u0e49\u0e33\u0e21\u0e31\u0e19 \u0e01\u0e4a\u0e32\u0e0b \u0e1b\u0e34\u0e42\u0e15\u0e23\u0e40\u0e04\u0e21\u0e35 \u0e1e\u0e25\u0e31\u0e07\u0e07\u0e32\u0e19 \u0e41\u0e25\u0e30\u0e2d\u0e38\u0e15\u0e2a\u0e32\u0e2b\u0e01\u0e23\u0e23\u0e21\u0e2d\u0e37\u0e48\u0e19 \u0e46 \u0e42\u0e14\u0e22\u0e2d\u0e31\u0e15\u0e42\u0e19\u0e21\u0e31\u0e15\u0e34 \u0e27\u0e32\u0e25\u0e4c\u0e27\u0e19\u0e35\u0e49\u0e21\u0e35\u0e43\u0e2b\u0e49\u0e40\u0e25\u0e37\u0e2d\u0e01\u0e43\u0e0a\u0e49\u0e43\u0e19\u0e27\u0e31\u0e2a\u0e14\u0e38\u0e40\u0e2b\u0e25\u0e47\u0e01\u0e04\u0e32\u0e23\u0e4c\u0e1a\u0e2d\u0e19 \u0e40\u0e2b\u0e25\u0e47\u0e01\u0e2a\u0e41\u0e15\u0e19\u0e40\u0e25\u0e2a \u0e41\u0e25\u0e30\u0e27\u0e31\u0e2a\u0e14\u0e38\u0e42\u0e25\u0e2b\u0e30\u0e1c\u0e2a\u0e21\u0e1e\u0e34\u0e40\u0e28\u0e29 \u0e1e\u0e23\u0e49\u0e2d\u0e21\u0e23\u0e30\u0e14\u0e31\u0e1a\u0e04\u0e27\u0e32\u0e21\u0e14\u0e31\u0e19\u0e15\u0e32\u0e21\u0e21\u0e32\u0e15\u0e23\u0e10\u0e32\u0e19 ASME Class 150 \u0e16\u0e36\u0e07 Class 1500.<\/p>\n

        \n
      • \u0e1b\u0e23\u0e30\u0e40\u0e20\u0e17\u0e27\u0e32\u0e25\u0e4c\u0e27:<\/strong> \u0e27\u0e32\u0e25\u0e4c\u0e27\u0e15\u0e23\u0e27\u0e08\u0e2a\u0e2d\u0e1a\u0e41\u0e1a\u0e1a\u0e2a\u0e27\u0e34\u0e07<\/li>\n
      • \u0e21\u0e32\u0e15\u0e23\u0e10\u0e32\u0e19\u0e01\u0e32\u0e23\u0e2d\u0e2d\u0e01\u0e41\u0e1a\u0e1a:<\/strong> API 6D, BS 1868 \u0e41\u0e25\u0e30 ASME B16.34<\/li>\n
      • \u0e0a\u0e48\u0e27\u0e07\u0e02\u0e19\u0e32\u0e14:<\/strong> NPS 2\u201324 \/ DN50\u2013DN600<\/li>\n
      • \u0e04\u0e48\u0e32\u0e04\u0e27\u0e32\u0e21\u0e14\u0e31\u0e19\u0e17\u0e35\u0e48\u0e01\u0e33\u0e2b\u0e19\u0e14:<\/strong> ASME Class 150\u20131500<\/li>\n
      • \u0e27\u0e31\u0e2a\u0e14\u0e38\u0e15\u0e31\u0e27\u0e40\u0e04\u0e23\u0e37\u0e48\u0e2d\u0e07:<\/strong> WCB, CF8, CF8M, CF3 \u0e41\u0e25\u0e30\u0e42\u0e25\u0e2b\u0e30\u0e1c\u0e2a\u0e21\u0e2d\u0e37\u0e48\u0e19\u0e46<\/li>\n
      • \u0e08\u0e38\u0e14\u0e15\u0e48\u0e2d\u0e1b\u0e25\u0e32\u0e22:<\/strong> \u0e1b\u0e25\u0e32\u0e22\u0e41\u0e1a\u0e1a RF, RTJ \u0e2b\u0e23\u0e37\u0e2d\u0e1b\u0e25\u0e32\u0e22\u0e15\u0e48\u0e2d\u0e41\u0e1a\u0e1a butt-weld<\/li>\n
      • \u0e21\u0e32\u0e15\u0e23\u0e10\u0e32\u0e19\u0e01\u0e32\u0e23\u0e17\u0e14\u0e2a\u0e2d\u0e1a:<\/strong> API 598<\/li>\n<\/ul>","protected":false},"featured_media":870,"comment_status":"open","ping_status":"closed","template":"","meta":{"_kad_post_transparent":"default","_kad_post_title":"","_kad_post_layout":"default","_kad_post_sidebar_id":"","_kad_post_content_style":"default","_kad_post_vertical_padding":"default","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":""},"product_brand":[72],"product_cat":[37,32,31,40],"product_tag":[],"class_list":["post-284","product","type-product","status-publish","has-post-thumbnail","product_brand-wdl-valve","product_cat-check-valves","product_cat-valve-materials","product_cat-valve-types","product_cat-carbon-steel-valves","first","instock","shipping-taxable","product-type-simple","entry","content-bg","loop-entry"],"_links":{"self":[{"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/product\/284","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/comments?post=284"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/media\/870"}],"wp:attachment":[{"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/media?parent=284"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/product_brand?post=284"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/product_cat?post=284"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/wdlvalve.com\/th\/wp-json\/wp\/v2\/product_tag?post=284"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}