{"id":864,"date":"2026-04-09T12:36:34","date_gmt":"2026-04-09T04:36:34","guid":{"rendered":""},"modified":"2026-04-10T00:19:16","modified_gmt":"2026-04-10T04:19:16","slug":"flange-bolt-torque-chart-tightening-procedures","status":"publish","type":"post","link":"https:\/\/www.songhaiflange.com\/vi\/2026\/04\/09\/flange-bolt-torque-chart-tightening-procedures\/","title":{"rendered":"Flange Bolt Torque Chart: Proper Tightening Procedures"},"content":{"rendered":"<figure class=\"flange-image\"><img decoding=\"async\" style=\"max-width: 100%; height: auto; margin: 20px 0; border: 1px solid #ddd; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,0.1);\" src=\"\/wp-content\/uploads\/flange-images\/torque-chart.svg\" alt=\"Bolt Torque Sequence\" title=\"\"><\/figure>\n<h1>Flange Bolt Torque Chart: Proper Tightening Procedures<\/h1>\n<p><strong>Proper bolt torque<\/strong> is critical for leak-free flange connections. Under-torquing causes leaks; over-torquing can damage gaskets or warp flanges.<\/p>\n<h2>Why Bolt Torque Matters<\/h2>\n<p>Flange bolts must create sufficient gasket compression to seal without exceeding material yield strength. The correct torque ensures:<\/p>\n<ul>\n<li>Uniform gasket compression<\/li>\n<li>Prevention of bolt relaxation<\/li>\n<li>Avoidance of gasket blowout<\/li>\n<li>Extended service life<\/li>\n<\/ul>\n<h2>Torque Calculation Formula<\/h2>\n<p><strong>T = K \u00d7 D \u00d7 F<\/strong><\/p>\n<ul>\n<li>T = M\u00f4-men xo\u1eafn (Nm ho\u1eb7c ft-lbs)<\/li>\n<li>K = Nut factor (friction coefficient, typically 0.2)<\/li>\n<li>D = \u0110\u01b0\u1eddng k\u00ednh danh ngh\u0129a c\u1ee7a bu l\u00f4ng (mm ho\u1eb7c inch)<\/li>\n<li>F = Bolt load (N or lbs)<\/li>\n<\/ul>\n<h2>ASME B16.5 Bolt Torque Chart<\/h2>\n<table>\n<tbody>\n<tr>\n<th>Flange Size<\/th>\n<th>Class 150<\/th>\n<th>Class 300<\/th>\n<th>Class 600<\/th>\n<\/tr>\n<tr>\n<td>1\/2&#8243; (DN15)<\/td>\n<td>15 ft-lbs<\/td>\n<td>25 ft-lbs<\/td>\n<td>40 ft-lbs<\/td>\n<\/tr>\n<tr>\n<td>1&#8243; (DN25)<\/td>\n<td>45 ft-lbs<\/td>\n<td>75 ft-lbs<\/td>\n<td>120 ft-lbs<\/td>\n<\/tr>\n<tr>\n<td>2&#8243; (DN50)<\/td>\n<td>95 ft-lbs<\/td>\n<td>160 ft-lbs<\/td>\n<td>250 ft-lbs<\/td>\n<\/tr>\n<tr>\n<td>4&#8243; (DN100)<\/td>\n<td>185 ft-lbs<\/td>\n<td>310 ft-lbs<\/td>\n<td>490 ft-lbs<\/td>\n<\/tr>\n<tr>\n<td>6&#8243; (DN150)<\/td>\n<td>280 ft-lbs<\/td>\n<td>470 ft-lbs<\/td>\n<td>740 ft-lbs<\/td>\n<\/tr>\n<tr>\n<td>8&#8243; (DN200)<\/td>\n<td>380 ft-lbs<\/td>\n<td>640 ft-lbs<\/td>\n<td>1010 ft-lbs<\/td>\n<\/tr>\n<tr>\n<td>12&#8243; (DN300)<\/td>\n<td>570 ft-lbs<\/td>\n<td>960 ft-lbs<\/td>\n<td>1520 ft-lbs<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Proper Bolt Tightening Sequence<\/h2>\n<ol>\n<li><strong>Cross-pattern tightening:<\/strong> Start at 12 o&#8217;clock, opposite at 6 o&#8217;clock<\/li>\n<li><strong>30% torque:<\/strong> Snug all bolts in sequence<\/li>\n<li><strong>60% torque:<\/strong> Second pass in same sequence<\/li>\n<li><strong>100% torque:<\/strong> Final pass to specified torque<\/li>\n<li><strong>Check:<\/strong> Verify all bolts reach target torque<\/li>\n<\/ol>\n<h2>Common Torque Mistakes<\/h2>\n<ul>\n<li>\u274c Using impact wrenches (causes uneven loading)<\/li>\n<li>\u274c Tightening bolts sequentially around circle (warps flange)<\/li>\n<li>\u274c Reusing damaged or stretched bolts<\/li>\n<li>\u274c Not lubricating threads (increases friction)<\/li>\n<li>\u274c Ignoring gasket type (different compression requirements)<\/li>\n<\/ul>\n<h2>Torque Tools Recommendation<\/h2>\n<ul>\n<li>Calibrated torque wrench (click type or digital)<\/li>\n<li>Torque multiplier for large bolts<\/li>\n<li>Hydraulic torque wrench for critical applications<\/li>\n<li>Bolt tensioner for large diameter flanges<\/li>\n<\/ul>\n<div class=\"quote-box\">\n<h3>\ud83d\udcde Download Full Torque Chart<\/h3>\n<p><strong>WhatsApp:<\/strong> +86-18658777855<\/p>\n<p><strong>Email:<\/strong> 1007788887@qq.com<\/p>\n<p>\u2713 Complete torque tables \u2713 Installation guides \u2713 Technical support<\/p>\n<\/div>\n<p><a href=\"https:\/\/www.720yun.com\/vr\/a6ajt7ynrw0\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-884\" src=\"http:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4.webp\" alt=\"\" width=\"1290\" height=\"2317\" title=\"\" srcset=\"https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4.webp 1290w, https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4-167x300.webp 167w, https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4-570x1024.webp 570w, https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4-768x1379.webp 768w, https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4-855x1536.webp 855w, https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4-1140x2048.webp 1140w, https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4-7x12.webp 7w, https:\/\/www.songhaiflange.com\/wp-content\/uploads\/2026\/04\/4-416x747.webp 416w\" sizes=\"auto, (max-width: 1290px) 100vw, 1290px\" \/><\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Complete flange bolt torque chart and tightening procedures. Learn proper torque values for ASME B16.5 Class 150-2500 flanges. Prevent leaks with correct installation.<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-864","post","type-post","status-publish","format-standard","hentry","category-blog"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/posts\/864","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/comments?post=864"}],"version-history":[{"count":4,"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/posts\/864\/revisions"}],"predecessor-version":[{"id":907,"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/posts\/864\/revisions\/907"}],"wp:attachment":[{"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/media?parent=864"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/categories?post=864"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.songhaiflange.com\/vi\/wp-json\/wp\/v2\/tags?post=864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}