{"id":100188,"date":"2026-02-15T20:25:47","date_gmt":"2026-02-15T20:25:47","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100188"},"modified":"2026-04-05T15:36:46","modified_gmt":"2026-04-05T15:36:46","slug":"pipe-wall-thickness-pressure","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/bn\/calculators\/pipe-wall-thickness-pressure\/","title":{"rendered":"Pipe Wall Thickness Calculator \u2014 Barlow&#8217;s Formula"},"content":{"rendered":"\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Pipe Wall Thickness Calculator\",\"description\":\"Free calculator using Barlow's formula t=PD\/(2SE) for pipe wall thickness under internal pressure.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/pipe-wall-thickness-pressure\/\",\"applicationCategory\":\"Engineering Calculator\",\"operatingSystem\":\"Any\",\"offers\":{\"@type\":\"Offer\",\"price\":\"0\",\"priceCurrency\":\"EUR\"},\"creator\":{\"@type\":\"Organization\",\"name\":\"Vibromera\",\"url\":\"https:\/\/vibromera.eu\/\"},\"datePublished\":\"2024-01-01\",\"dateModified\":\"2025-06-15\",\"inLanguage\":\"en\",\"isAccessibleForFree\":true}<\/script>\n\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[\n{\"@type\":\"Question\",\"name\":\"What is Barlow's formula?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Barlow's formula calculates minimum wall thickness for pipes under internal pressure: t = P \u00d7 D \/ (2 \u00d7 S \u00d7 E), where P = internal pressure, D = outside diameter, S = allowable stress, E = weld joint efficiency factor.\"}},\n{\"@type\":\"Question\",\"name\":\"What allowable stress should I use?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Allowable stress depends on material and temperature. For carbon steel (A106 Gr.B) at ambient: ~138 MPa (20,000 psi). For stainless 316 at ambient: ~138 MPa. Always refer to ASME B31.3 Table A-1 for design values.\"}},\n{\"@type\":\"Question\",\"name\":\"What is the weld joint efficiency factor?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Weld efficiency (E) accounts for joint quality: E = 1.0 for seamless pipe, E = 0.85 for ERW (electric resistance welded), E = 0.60 for furnace butt welded. Higher E requires more inspection (radiography).\"}},\n{\"@type\":\"Question\",\"name\":\"Do I need to add a corrosion allowance?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. Add corrosion\/erosion allowance (typically 1.5\u20133 mm for carbon steel in process service) to the calculated minimum wall thickness. Also consider manufacturing tolerance (typically -12.5% for seamless pipe).\"}},\n{\"@type\":\"Question\",\"name\":\"What is the difference between Barlow and ASME B31.3?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Barlow's formula is a simplified version. ASME B31.3 uses t = PD\/(2(SE+PY)), where Y is a temperature coefficient. For most cases at moderate temperatures, Y \u2248 0.4. The ASME formula gives slightly thinner walls.\"}}\n]}<\/script>\n\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"BreadcrumbList\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/vibromera.eu\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Calculators\",\"item\":\"https:\/\/vibromera.eu\/calculators\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Pipe Wall Thickness\",\"item\":\"https:\/\/vibromera.eu\/calculators\/pipe-wall-thickness-pressure\/\"}]}<\/script>\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin>\n\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&#038;family=JetBrains+Mono:wght@400;500;600&#038;family=Fraunces:opsz,wght@9..144,700;9..144,800&#038;display=swap\" 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16px;font-size:13px;color:var(--vc-ink-muted)}.vc-footer a{color:var(--vc-accent);text-decoration:none}.vc-footer a:hover{text-decoration:underline}.vc-footer-links{margin-top:8px;font-size:12px}.vc-footer-links a{margin:0 8px}\n@media print{.vc-section-body{max-height:none!important}.vc-faq-a{max-height:none!important}.vc-results{max-height:none!important;padding:24px!important}.vc-copy-btn,.vc-section-chevron,.vc-faq-chevron,.vc-presets,.vc-promo{display:none!important}}\n<\/style>\n\n<div class=\"vc-calculator\" id=\"vc-pipe-wall\">\n<header class=\"vc-header\">\n    <p class=\"vc-header-eyebrow\">Free Engineering Tool \u2014 #154<\/p>\n    <h1 class=\"vc-header-title\">Pipe Wall Thickness Calculator \u2014 Barlow&#8217;s Formula<\/h1>\n    <p class=\"vc-header-subtitle\">Calculate minimum wall thickness for pipes under internal pressure using Barlow&#8217;s formula: t = P\u00d7D\/(2\u00d7S\u00d7E). Includes corrosion allowance and tolerance.<\/p>\n    <div class=\"vc-badges\"><span class=\"vc-badge\">t = PD\/(2SE)<\/span><span class=\"vc-badge\">ASME B31.3<\/span><span class=\"vc-badge\">Corrosion Allowance<\/span><\/div>\n<\/header>\n\n<div class=\"vc-card\">\n    <form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\">\n        <div class=\"vc-form-grid\">\n            <div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-pressure\">Design Pressure <span class=\"vc-label-hint\">(MPa)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-pressure\" inputmode=\"decimal\" step=\"any\" min=\"0\" value=\"10\"><\/div>\n            <div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-od\">Pipe OD <span class=\"vc-label-hint\">(mm)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-od\" inputmode=\"decimal\" step=\"any\" min=\"0.1\" value=\"114.3\"><\/div>\n            <div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-stress\">Allowable Stress (S) <span class=\"vc-label-hint\">(MPa)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-stress\" inputmode=\"decimal\" step=\"any\" min=\"0\" value=\"138\"><\/div>\n            <div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-weld\">Weld Joint Factor (E) <span class=\"vc-label-hint\">(0\u20131)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-weld\" inputmode=\"decimal\" step=\"any\" min=\"0\" max=\"1\" value=\"1.0\"><\/div>\n            <div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-corr\">Corrosion Allowance <span class=\"vc-label-hint\">(mm)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-corr\" inputmode=\"decimal\" step=\"any\" min=\"0\" value=\"1.5\"><\/div>\n            <div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-tol\">Mill Tolerance <span class=\"vc-label-hint\">(%)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-tol\" inputmode=\"decimal\" step=\"any\" min=\"0\" value=\"12.5\"><\/div>\n        <\/div>\n        <div class=\"vc-presets\">\n            <div class=\"vc-presets-label\">Quick presets<\/div>\n            <button type=\"button\" class=\"vc-preset-btn\" data-p=\"1\" data-od=\"60.3\" data-s=\"138\" data-e=\"1\">DN50, 1 MPa, seamless<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-p=\"10\" data-od=\"114.3\" data-s=\"138\" data-e=\"1\">DN100, 10 MPa, seamless<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-p=\"20\" data-od=\"219.1\" data-s=\"138\" data-e=\"0.85\">DN200, 20 MPa, ERW<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-p=\"40\" data-od=\"323.9\" data-s=\"138\" data-e=\"1\">DN300, 40 MPa, seamless<\/button>\n        <\/div>\n    <\/form>\n    <div class=\"vc-results\" id=\"vc-results\">\n        <div class=\"vc-results-head\"><h2 class=\"vc-results-title\">Results<\/h2><button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\"><svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><rect x=\"9\" y=\"9\" width=\"13\" height=\"13\" rx=\"2\"\/><path d=\"M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1\"\/><\/svg> Copy<\/button><\/div>\n        <div class=\"vc-result-grid\">\n            <div class=\"vc-rcard vc-rcard-primary\"><div class=\"vc-rcard-label\">Minimum Required Wall Thickness (incl. corrosion &amp; tolerance)<\/div><div class=\"vc-rcard-value\" id=\"vc-r-tmin\">\u2014<\/div><\/div>\n            <div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Calculated t (Barlow)<\/div><div class=\"vc-rcard-value\" id=\"vc-r-tcalc\">\u2014<\/div><\/div>\n            <div class=\"vc-rcard\"><div class=\"vc-rcard-label\">+ Corrosion Allowance<\/div><div class=\"vc-rcard-value\" id=\"vc-r-tcorr\">\u2014<\/div><\/div>\n            <div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Burst Pressure (2\u00d7S\u00d7E\u00d7t\/D)<\/div><div class=\"vc-rcard-value\" id=\"vc-r-burst\">\u2014<\/div><\/div>\n            <div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Internal Diameter<\/div><div class=\"vc-rcard-value\" id=\"vc-r-id\">\u2014<\/div><\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<div class=\"vc-section vc-open\" id=\"vc-sec-theory\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udcd8<\/span><span class=\"vc-section-title\">Theory &amp; Formulas<\/span><\/span><svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg><\/button>\n    <div class=\"vc-section-body\"><div class=\"vc-section-inner vc-theory\">\n        <h3>Barlow&#8217;s Formula<\/h3>\n        <div class=\"vc-formula-box\" id=\"vc-katex-1\"><\/div>\n        <h3>With Corrosion and Tolerance<\/h3>\n        <div class=\"vc-formula-box\" id=\"vc-katex-2\"><\/div>\n        <ul>\n            <li><strong>P<\/strong> \u2014 design pressure<\/li>\n            <li><strong>D<\/strong> \u2014 pipe outside diameter<\/li>\n            <li><strong>S<\/strong> \u2014 allowable stress at design temperature<\/li>\n            <li><strong>E<\/strong> \u2014 weld joint efficiency (1.0 seamless, 0.85 ERW, 0.60 FBW)<\/li>\n            <li><strong>c<\/strong> \u2014 corrosion\/erosion allowance<\/li>\n            <li><strong>tol<\/strong> \u2014 manufacturing tolerance (typically 12.5%)<\/li>\n        <\/ul>\n        <div class=\"vc-example-box\"><div class=\"vc-example-title\">Example \u2014 DN100 at 10 MPa<\/div>\n            <p><strong>Given:<\/strong> OD = 114.3 mm, P = 10 MPa, S = 138 MPa, E = 1.0<\/p>\n            <p>t = 10 \u00d7 114.3 \/ (2 \u00d7 138 \u00d7 1.0) = <strong>4.14 mm<\/strong><\/p>\n            <p>+ 1.5 mm corrosion = 5.64 mm<\/p>\n            <p>\u00f7 (1 \u2212 0.125) = <strong>6.45 mm minimum<\/strong><\/p>\n            <p>Select Sch 80 (8.56 mm wall) for this service.<\/p>\n        <\/div>\n        <div class=\"vc-warning-box\"><p style=\"margin:0;font-size:14px;color:var(--vc-ink-secondary);\"><strong>\u26a0\ufe0f Note:<\/strong> This is Barlow&#8217;s simplified formula. For code compliance, use ASME B31.3 Eq. 3a which includes the Y factor. Always select the next standard pipe schedule above the calculated minimum.<\/p><\/div>\n    <\/div><\/div>\n<\/div>\n\n<div class=\"vc-section\" id=\"vc-sec-related\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udd17<\/span><span class=\"vc-section-title\">Related Calculators<\/span><\/span><svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg><\/button>\n    <div class=\"vc-section-body\"><div class=\"vc-section-inner\"><div class=\"vc-related\">\n        <a class=\"vc-related-link\" href=\"\/calculators\/steel-pipe-dimensions-iso4200\/\">Pipe Dimensions ISO 4200<\/a>\n        <a class=\"vc-related-link\" href=\"\/calculators\/flange-gasket-calculator\/\">Flange Gasket<\/a>\n        <a class=\"vc-related-link\" href=\"\/calculators\/orifice-flow-calculator-iso5167\/\">Orifice Flow ISO 5167<\/a>\n    <\/div><\/div><\/div>\n<\/div>\n\n<div class=\"vc-section\" id=\"vc-sec-faq\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\u2753<\/span><span class=\"vc-section-title\">Frequently Asked Questions<\/span><\/span><svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg><\/button>\n    <div class=\"vc-section-body\"><div class=\"vc-section-inner\"><div class=\"vc-faq-list\" id=\"vc-faq-list\"><\/div><\/div><\/div>\n<\/div>\n\n<div class=\"vc-promo\"><div class=\"vc-promo-text\"><strong>Vibromera \u2014 Portable Balancing &amp; Vibration Analysis<\/strong><br>Professional instruments. 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Last updated: June 2025<\/p><div class=\"vc-footer-links\"><a href=\"\/calculators\/engineering-calculators\/\">All Calculators<\/a><a href=\"https:\/\/vibromera.eu\/contacts\/\">Contact<\/a><\/div><\/footer>\n<\/div>\n\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/katex@0.16.11\/dist\/katex.min.js\"><\/script>\n<script>\n(function(){\n    'use strict';\n    function $(id){return document.getElementById(id)}\n    function fmt(n,d){if(isNaN(n)||!isFinite(n))return '\u2014';return n.toFixed(d===undefined?2:d).replace(\/(\\.\\d*?)0+$\/,'$1').replace(\/\\.$\/,'')}\n\n    function calculate(){\n        var P=parseFloat($('vc-pressure').value);\n        var OD=parseFloat($('vc-od').value);\n        var S=parseFloat($('vc-stress').value);\n        var E=parseFloat($('vc-weld').value);\n        var corr=parseFloat($('vc-corr').value)||0;\n        var tol=parseFloat($('vc-tol').value)||0;\n        if(!P||P<=0||!OD||OD<=0||!S||S<=0||!E||E<=0){$('vc-results').classList.remove('vc-visible');return}\n\n        var tCalc=P*OD\/(2*S*E);\n        var tCorr=tCalc+corr;\n        var tMin=tCorr\/(1-tol\/100);\n        var burstP=2*S*E*tCalc\/OD;\n        var ID=OD-2*tMin;\n\n        $('vc-r-tmin').innerHTML=fmt(tMin,2)+' <span class=\"vc-rcard-unit\">mm<\/span>';\n        $('vc-r-tcalc').innerHTML=fmt(tCalc,2)+' <span class=\"vc-rcard-unit\">mm<\/span>';\n        $('vc-r-tcorr').innerHTML=fmt(tCorr,2)+' <span class=\"vc-rcard-unit\">mm<\/span>';\n        $('vc-r-burst').innerHTML=fmt(burstP,1)+' <span class=\"vc-rcard-unit\">MPa<\/span>';\n        $('vc-r-id').innerHTML=fmt(ID,1)+' <span class=\"vc-rcard-unit\">mm<\/span>';\n        $('vc-results').classList.add('vc-visible');\n    }\n\n    document.querySelectorAll('.vc-preset-btn').forEach(function(btn){btn.addEventListener('click',function(e){e.preventDefault();$('vc-pressure').value=this.getAttribute('data-p');$('vc-od').value=this.getAttribute('data-od');$('vc-stress').value=this.getAttribute('data-s');$('vc-weld').value=this.getAttribute('data-e');calculate()})});\n\n    $('vc-form').addEventListener('input',calculate);$('vc-form').addEventListener('change',calculate);\n\n    $('vc-copy-btn').addEventListener('click',function(){var text='Pipe Wall Thickness (Barlow)\\n\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\\nP='+$('vc-pressure').value+' MPa, OD='+$('vc-od').value+' mm\\nS='+$('vc-stress').value+' MPa, E='+$('vc-weld').value+'\\nt(calc)='+$('vc-r-tcalc').textContent+'\\nt(min)='+$('vc-r-tmin').textContent+'\\n\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\\nvibromera.eu';if(navigator.clipboard){navigator.clipboard.writeText(text).then(function(){var b=$('vc-copy-btn');b.classList.add('vc-copied');b.innerHTML='<svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><polyline points=\"20 6 9 17 4 12\"\/><\/svg> Copied!';setTimeout(function(){b.classList.remove('vc-copied');b.innerHTML='<svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><rect x=\"9\" y=\"9\" width=\"13\" height=\"13\" rx=\"2\"\/><path d=\"M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1\"\/><\/svg> Copy'},2000)})}});\n\n    document.querySelectorAll('.vc-section-toggle').forEach(function(btn){btn.addEventListener('click',function(){var s=this.closest('.vc-section');s.classList.toggle('vc-open');this.setAttribute('aria-expanded',s.classList.contains('vc-open'))})});\n\n    var faqData=[\n        {q:'What is Barlow\\'s formula?',a:'<p>t = P\u00d7D\/(2\u00d7S\u00d7E). Calculates minimum wall thickness for pipes under internal pressure. P = pressure, D = OD, S = allowable stress, E = weld efficiency.<\/p>'},\n        {q:'What allowable stress should I use?',a:'<p>Depends on material and temperature. Carbon steel A106 Gr.B at ambient: ~138 MPa. See ASME B31.3 Table A-1 for precise values at design temperature.<\/p>'},\n        {q:'What is weld joint efficiency?',a:'<p>E = 1.0 for seamless, 0.85 for ERW, 0.60 for furnace butt welded. Higher E needs more NDE (radiography). Per ASME B31.3 Table A-1B.<\/p>'},\n        {q:'Do I need corrosion allowance?',a:'<p>Yes. Typically 1.5\u20133 mm for carbon steel in process service. Also add -12.5% mill tolerance for seamless pipe (per ASTM A106).<\/p>'},\n        {q:'Barlow vs ASME B31.3?',a:'<p>ASME B31.3 uses t = PD\/(2(SE+PY)), where Y \u2248 0.4 at moderate temperatures. This gives a slightly thinner result. 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