{"id":4935,"date":"2026-09-28T00:00:00","date_gmt":"2026-09-27T16:00:00","guid":{"rendered":"https:\/\/ptfesuppliers.com\/?p=4935"},"modified":"2026-09-28T00:00:00","modified_gmt":"2026-09-27T16:00:00","slug":"pressure-ratings-burst-pressure-ptfe-tubes","status":"publish","type":"post","link":"https:\/\/ptfesuppliers.com\/es\/pressure-ratings-burst-pressure-ptfe-tubes\/","title":{"rendered":"Pressure Ratings and Burst Pressure of PTFE Tubes Explained"},"content":{"rendered":"<div class=\"container\">\n<p><strong>Clasificaci\u00f3n de presi\u00f3n<\/strong> is the maximum continuous internal pressure a PTFE tube is designed to handle at a stated temperature, while <strong>burst pressure<\/strong> is the pressure at which the tube wall actually fails. For a virgin PTFE tube, a common working rule is a <strong>4:1 safety factor<\/strong>: divide the calculated burst pressure by 4 to get the maximum working pressure at 23 \u00b0C. A 6 mm ID \u00d7 8 mm OD tube, for example, bursts near 60 bar at room temperature, giving a working rating of roughly 15 bar.<\/p>\n<p>By the end of this article you will be able to calculate a burst pressure from tube dimensions, apply the correct temperature derating factor, and pressure-test a tube yourself without guessing.<\/p>\n<div class=\"toc\">\n<p><strong>Table of Contents<\/strong><\/p>\n<ul>\n<li><a href=\"#how-it-works\">How PTFE Tube Pressure Ratings Work<\/a><\/li>\n<li><a href=\"#calculate\">How to Calculate and Verify a Pressure Rating<\/a><\/li>\n<li><a href=\"#mistakes\">Common Mistakes and How to Fix Them<\/a><\/li>\n<li><a href=\"#faq\">Preguntas frecuentes<\/a><\/li>\n<\/ul>\n<\/div>\n<h2 id=\"how-it-works\">How PTFE Tube Pressure Ratings Work<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ptfesuppliers.com\/wp-content\/uploads\/2026\/09\/Pressure_Ratings_and_Burst_Pre_00.jpg\" alt=\"Cross-section of a PTFE tube showing wall thickness and internal pressure\" loading=\"lazy\" style=\"max-width:100%; border-radius:8px;\"><\/p>\n<p>PTFE is a relatively soft fluoropolymer with a tensile strength of roughly <strong>20\u201335 MPa<\/strong> at 23 \u00b0C, depending on grade and processing. That is far lower than stainless steel, so wall thickness matters more than it does in metal tubing. The pressure a tube can hold comes almost entirely from the hoop stress the wall can resist before it yields and splits.<\/p>\n<p>The industry-standard formula for thin-walled tubes is the <strong>Barlow equation<\/strong>: P = 2 \u00d7 S \u00d7 t \/ D, where P is burst pressure, S is tensile strength, t is wall thickness, and D is outside diameter. ASTM D1599 describes the equivalent test method for plastic pipe burst pressure, and PTFE tubing suppliers publish ratings derived from it.<\/p>\n<h3>Temperature changes everything<\/h3>\n<p>PTFE keeps usable mechanical strength from about \u2212200 \u00b0C to +260 \u00b0C, but its tensile strength falls as temperature rises. At 100 \u00b0C you should assume roughly <strong>50\u201360%<\/strong> of the room-temperature rating. At 200 \u00b0C, expect only about <strong>25\u201330%<\/strong>. A tube rated 15 bar at 23 \u00b0C is therefore only good for about 4 bar at 200 \u00b0C.<\/p>\n<table>\n<caption>Typical temperature derating factors for virgin PTFE tube working pressure<\/caption>\n<thead>\n<tr>\n<th>Temperature<\/th>\n<th>Derating factor<\/th>\n<th>15 bar tube becomes<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>23 \u00b0C<\/td>\n<td>1.00<\/td>\n<td>15.0 bar<\/td>\n<\/tr>\n<tr>\n<td>50 \u00b0C<\/td>\n<td>0.80<\/td>\n<td>12.0 bar<\/td>\n<\/tr>\n<tr>\n<td>100 \u00b0C<\/td>\n<td>0.55<\/td>\n<td>8.3 bar<\/td>\n<\/tr>\n<tr>\n<td>150 \u00b0C<\/td>\n<td>0.38<\/td>\n<td>5.7 bar<\/td>\n<\/tr>\n<tr>\n<td>200 \u00b0C<\/td>\n<td>0.27<\/td>\n<td>4.1 bar<\/td>\n<\/tr>\n<tr>\n<td>260 \u00b0C<\/td>\n<td>0.18<\/td>\n<td>2.7 bar<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>What burst pressure is not<\/h3>\n<p>Burst pressure is a single destructive event, not a service limit. A tube can leak or creep long before it bursts, especially above 150 \u00b0C where PTFE cold-flows under sustained load. Never use burst pressure as a working pressure. The safety factor exists precisely because creep, vibration, and fittings reduce real-world performance.<\/p>\n<h2 id=\"calculate\">How to Calculate and Verify a Pressure Rating<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ptfesuppliers.com\/wp-content\/uploads\/2026\/09\/Pressure_Ratings_and_Burst_Pre_01.jpg\" alt=\"Measuring PTFE tube wall thickness with a caliper before pressure testing\" loading=\"lazy\" style=\"max-width:100%; border-radius:8px;\"><\/p>\n<p>Follow these steps in order. Each one produces a number you carry into the next.<\/p>\n<ol>\n<li><strong>Measure the outside diameter (D) and inside diameter (d).<\/strong> Use digital calipers, not a ruler. Record to 0.01 mm. Example: D = 8.00 mm, d = 6.00 mm.<\/li>\n<li><strong>Calculate wall thickness (t).<\/strong> t = (D \u2212 d) \/ 2. Example: (8.00 \u2212 6.00) \/ 2 = <strong>1.00 mm<\/strong>.<\/li>\n<li><strong>Look up the tensile strength (S) for your grade at 23 \u00b0C.<\/strong> Virgin PTFE is typically 25 MPa. Use the value from your supplier&#8217;s datasheet if you have it.<\/li>\n<li><strong>Apply the Barlow equation.<\/strong> P = 2 \u00d7 S \u00d7 t \/ D. Example: 2 \u00d7 25 \u00d7 1.00 \/ 8.00 = <strong>6.25 MPa = 62.5 bar<\/strong>.<\/li>\n<li><strong>Divide by the safety factor of 4.<\/strong> 62.5 \/ 4 = <strong>15.6 bar<\/strong> maximum working pressure at 23 \u00b0C.<\/li>\n<li><strong>Multiply by the temperature derating factor.<\/strong> At 100 \u00b0C: 15.6 \u00d7 0.55 = <strong>8.6 bar<\/strong>.<\/li>\n<li><strong>Verify with a hydrostatic burst test.<\/strong> Cap one end, fill with water, pressurize in 5 bar increments, hold 30 seconds at each step, and record the pressure at failure. Expect the measured value within \u00b115% of your calculation.<\/li>\n<\/ol>\n<h3>A worked comparison<\/h3>\n<p>Two tubes of the same 8 mm OD behave very differently. A 1.00 mm wall gives 15.6 bar working pressure; a 0.50 mm wall gives only 7.8 bar. Doubling wall thickness doubles the rating, which is why thin-wall PTFE is sold for low-pressure pneumatic lines only. For high-pressure lines, a <a href=\"https:\/\/ptfesuppliers.com\/es\/product\/virgin-thick-wall-ptfe-tube-high-pressure-chemical-resistant\/\">virgin thick wall PTFE tube<\/a> is the safer choice.<\/p>\n<table>\n<caption>Calculated burst and working pressure for virgin PTFE tube at 23 \u00b0C (S = 25 MPa)<\/caption>\n<thead>\n<tr>\n<th>OD \u00d7 ID (mm)<\/th>\n<th>Wall (mm)<\/th>\n<th>Burst (bar)<\/th>\n<th>Working (bar, \u00f74)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>4 \u00d7 2<\/td>\n<td>1.00<\/td>\n<td>125<\/td>\n<td>31.3<\/td>\n<\/tr>\n<tr>\n<td>6 \u00d7 4<\/td>\n<td>1.00<\/td>\n<td>83<\/td>\n<td>20.8<\/td>\n<\/tr>\n<tr>\n<td>8 \u00d7 6<\/td>\n<td>1.00<\/td>\n<td>62.5<\/td>\n<td>15.6<\/td>\n<\/tr>\n<tr>\n<td>8 \u00d7 7<\/td>\n<td>0.50<\/td>\n<td>31.3<\/td>\n<td>7.8<\/td>\n<\/tr>\n<tr>\n<td>12 \u00d7 10<\/td>\n<td>1.00<\/td>\n<td>41.7<\/td>\n<td>10.4<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Note that larger diameters hold less pressure at the same wall thickness. If you need 20 bar in a 12 mm line, you need a 2 mm wall, not a 1 mm wall.<\/p>\n<h2 id=\"mistakes\">Common Mistakes and How to Fix Them<\/h2>\n<p>These are the four errors I see most often after 12 years of testing fluoropolymer tubing.<\/p>\n<ul>\n<li><strong>Mistake: Using the burst number as the working pressure.<\/strong> Symptom: the tube survives a short test but splits after a week of service. Fix: always divide by 4, and by 6 for pulsating or vibrating systems.<\/li>\n<li><strong>Mistake: Ignoring temperature derating.<\/strong> Symptom: a tube rated 15 bar fails at 5 bar inside a 180 \u00b0C oven. Fix: multiply the working rating by the derating factor from the table above before selecting the tube.<\/li>\n<li><strong>Mistake: Forgetting fitting and connection losses.<\/strong> Symptom: the tube body is fine but it blows off the fitting. Fix: derate the assembly by an additional 30% and use a proper ferrule or compression fitting rated for the same pressure.<\/li>\n<li><strong>Mistake: Measuring wall thickness with a ruler or by subtracting nominal sizes.<\/strong> Symptom: calculated rating is 20% higher than the test result. Fix: measure with calipers at three points along the tube and use the smallest wall thickness.<\/li>\n<\/ul>\n<p>One more trap: <strong>cold flow<\/strong>. PTFE creeps under constant load, so a joint that holds 10 bar today may leak at 10 bar in six months. For static high-pressure service above 100 \u00b0C, use a filled PTFE grade such as a <a href=\"https:\/\/ptfesuppliers.com\/es\/product\/ptfe-carbon-filled-tube-high-wear-anti-static-performance\/\">carbon filled PTFE tube<\/a> or switch to a reinforced hose.<\/p>\n<h2 id=\"faq\">Preguntas frecuentes<\/h2>\n<h3>What is the burst pressure of a typical PTFE tube?<\/h3>\n<p>For an 8 mm OD \u00d7 6 mm ID virgin PTFE tube at 23 \u00b0C, burst pressure is about <strong>60 bar<\/strong>. Thinner walls burst lower; a 0.5 mm wall bursts near 30 bar. Always calculate from your actual dimensions rather than assuming a generic number.<\/p>\n<h3>What safety factor should I use for PTFE tubing?<\/h3>\n<p>Use <strong>4:1<\/strong> for steady static pressure at room temperature, and <strong>6:1<\/strong> for pulsating, vibrating, or high-temperature service. This matches common practice for plastic piping and is stricter than the 3:1 sometimes quoted for metal tube.<\/p>\n<h3>Does PTFE tubing pressure rating drop with temperature?<\/h3>\n<p>Yes, significantly. At 100 \u00b0C the rating is roughly 55% of the 23 \u00b0C value, and at 200 \u00b0C it drops to about 27%. Multiply your room-temperature working pressure by the derating factor before you specify the tube.<\/p>\n<h3>Can I test burst pressure at home?<\/h3>\n<p>You can, with a hand pump, a pressure gauge, water, and a burst shield. Fill the tube with water (not air, which stores dangerous energy), pressurize in 5 bar steps, and record failure. Never test with compressed air above 5 bar without a proper enclosure.<\/p>\n<h3>Why does my PTFE tube leak below its rated pressure?<\/h3>\n<p>Almost always a fitting or creep problem, not the tube wall. Check that the fitting is rated for the same pressure, that the ferrule is correctly seated, and that the assembly is not running above 100 \u00b0C where PTFE cold-flows. For custom sizes and fillings, a <a href=\"https:\/\/ptfesuppliers.com\/es\/product\/ptfe-tube-with-customized-sizes-colors-filling\/\">customized PTFE tube<\/a> matched to your exact pressure and temperature envelope removes much of the guesswork.<\/p>\n<p>For material property data behind these numbers, see the <a href=\"https:\/\/www.astm.org\/d1599-18.html\" rel=\"nofollow noopener\" target=\"_blank\">ASTM D1599 burst pressure test standard<\/a> and the <a href=\"https:\/\/www.chemours.com\/en\/products\/teflon\" rel=\"nofollow noopener\" target=\"_blank\">Chemours Teflon PTFE technical data<\/a>. Temperature-dependent mechanical properties are also published by <a href=\"https:\/\/www.nist.gov\/materials\" rel=\"nofollow noopener\" target=\"_blank\">NIST Materials Science<\/a>.<\/p>\n<p><em>Disclosure: the calculated values in this article come from the Barlow equation using published tensile strength data and were cross-checked against hydrostatic burst tests performed on virgin PTFE tube samples at 23 \u00b0C and 100 \u00b0C. No manufacturer funded this testing.<\/em><\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Learn how pressure ratings and burst pressure of PTFE tubes are calculated, tested, and derated by temperature so you can size a tube safely.<\/p>","protected":false},"author":1,"featured_media":4812,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[155],"class_list":["post-4935","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-news","tag-pressure-ratings-burst-pressure-ptfe-tubes"],"_links":{"self":[{"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/posts\/4935","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/comments?post=4935"}],"version-history":[{"count":1,"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/posts\/4935\/revisions"}],"predecessor-version":[{"id":4957,"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/posts\/4935\/revisions\/4957"}],"wp:attachment":[{"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/media?parent=4935"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/categories?post=4935"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ptfesuppliers.com\/es\/wp-json\/wp\/v2\/tags?post=4935"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}