{"id":343502,"date":"2025-11-26T08:59:00","date_gmt":"2025-11-26T14:59:00","guid":{"rendered":"https:\/\/www.globaloring.com\/?p=343502"},"modified":"2026-01-15T13:57:33","modified_gmt":"2026-01-15T19:57:33","slug":"preventing-o-ring-extrusion-and-spiral-failure","status":"publish","type":"post","link":"https:\/\/www.globaloring.com\/blog\/preventing-o-ring-extrusion-and-spiral-failure\/","title":{"rendered":"Preventing O-Ring Extrusion and Spiral Failure"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1.jpg\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"577\" src=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1-1024x577.jpg\" alt=\"\" class=\"wp-image-343659\" srcset=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1-1024x577.jpg 1024w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1-300x169.jpg 300w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1-768x433.jpg 768w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1-56x32.jpg 56w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1-500x282.jpg 500w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1-700x394.jpg 700w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-1.jpg 1500w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Extrusion occurs when pressure forces the o-ring into the hardware clearance gap.<\/li>\n\n\n\n<li>Spiral failure results from uneven friction that twists the o-ring during reciprocating motion.<\/li>\n\n\n\n<li>Thoughtful design practices that manage motion, pressure, friction, alignment, and groove geometry can prevent both failure modes.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Introduction<\/h2>\n\n\n\n<p>A sealing system&#8217;s design must account for <a href=\"https:\/\/www.globaloring.com\/causes-for-o-ring-failure\/\" data-type=\"link\" data-id=\"https:\/\/www.globaloring.com\/causes-for-o-ring-failure\/\" target=\"_blank\" rel=\"noreferrer noopener\">common o-ring failure modes<\/a> that compromise long-term reliability. Extrusion and spiral failure are crucial. They often happen quietly during operations. However, they can cause sudden, serious leaks when the seal fails to work.<\/p>\n\n\n\n<p>Extrusion typically occurs when pressure and clearance conditions exceed the limits of the elastomer, while spiral failure originates from frictional imbalances during reciprocating motion.<\/p>\n\n\n\n<p>System pressure profiles, stroke behavior, gland geometry, surface finish, lubrication conditions, and temperature exposure heavily influence both failure types. The early stages of the design stage must consider these factors to avoid premature seal failure.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Understanding O-Ring Extrusion<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2.png\"><img decoding=\"async\" width=\"1024\" height=\"431\" src=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-1024x431.png\" alt=\"\" class=\"wp-image-343664\" srcset=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-1024x431.png 1024w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-300x126.png 300w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-768x323.png 768w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-1536x646.png 1536w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-56x24.png 56w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-500x210.png 500w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2-700x295.png 700w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-2.png 1618w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<p>Extrusion happens when pressure forces the o-ring into the clearance gap between mating hardware components. Once extruded, material may shear off during reciprocating or vibratory motion, a phenomenon often referred to as nibbling. Damage typically appears on the low-pressure side of the o-ring, characterized by jagged and frayed edges.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Primary Causes of Extrusion<\/h3>\n\n\n\n<p>The following factors most commonly lead to extrusion when pressure, motion, or material properties cause the o-ring to exceed its ability to withstand the clearance gap.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Excessive Diametral Clearance: <\/strong>Larger gaps allow more material displacement under pressure.<\/li>\n\n\n\n<li><strong>High System Pressure: <\/strong>Exceeding the pressure rating of the elastomer, especially without reinforcement, increases the risk of extrusion.<\/li>\n\n\n\n<li><strong>Low Shore A Hardness: <\/strong>Softer o-rings deform more rapidly and are less resistant to extrusion.<\/li>\n\n\n\n<li><strong>Dynamic Loading: <\/strong>Movement accelerates nibbling, especially with pressure surges or misaligned components.<\/li>\n\n\n\n<li><strong>Thermal and Chemical Degradation: <\/strong>Exposure to heat or incompatible fluids can weaken the elastomer and promote extrusion.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Design Strategies to Prevent Extrusion<\/h3>\n\n\n\n<p>Standard practices lower the chance of extrusion. They do this by managing pressure, material changes, and the seal&#8217;s behavior in the gland.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Tighten Clearance Gaps: <\/strong>Minimize extrusion-prone gaps through careful <a href=\"https:\/\/www.globaloring.com\/o-ring-groove-design\/\" data-type=\"link\" data-id=\"https:\/\/www.globaloring.com\/o-ring-groove-design\/\" target=\"_blank\" rel=\"noreferrer noopener\">gland design<\/a> and machining tolerances.<\/li>\n\n\n\n<li><strong>Increase O-Ring Hardness: <\/strong>Use higher <a href=\"https:\/\/www.globaloring.com\/durometer\/\" data-type=\"link\" data-id=\"https:\/\/www.globaloring.com\/durometer\/\" target=\"_blank\" rel=\"noreferrer noopener\">durometer<\/a> compounds where appropriate.<\/li>\n\n\n\n<li><strong>Add Anti-Extrusion Devices: <\/strong>Place <a href=\"https:\/\/www.globaloring.com\/backup-rings\/\" data-type=\"link\" data-id=\"https:\/\/www.globaloring.com\/backup-rings\/\" target=\"_blank\" rel=\"noreferrer noopener\">backup rings<\/a> made of harder materials between the o-ring and the gap. This helps strengthen the seal and create a negligible clearance.<\/li>\n\n\n\n<li><strong>Avoid Pressure Spikes: <\/strong>Dampen sudden pressure peaks or pulsations in the system where possible.<\/li>\n\n\n\n<li><strong>Optimize Hardware Alignment: <\/strong>Align pistons, rods, and seal glands appropriately to prevent eccentric gaps.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Understanding O-Ring Spiral Failure<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3.png\"><img decoding=\"async\" width=\"1024\" height=\"204\" src=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-1024x204.png\" alt=\"\" class=\"wp-image-343665\" srcset=\"https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-1024x204.png 1024w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-300x60.png 300w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-768x153.png 768w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-1536x306.png 1536w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-56x11.png 56w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-500x100.png 500w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3-700x139.png 700w, https:\/\/www.globaloring.com\/wp-content\/uploads\/2025\/11\/Blog-82-Image-3.png 1618w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<p>Spiral failure is a dynamic failure mode typically seen in reciprocating seals. It manifests as a tight spiral or corkscrew-shaped tear across the o-ring&#8217;s cross-section. Unlike extrusion, the o-ring may continue to seal until the damage progresses to a complete rupture.<\/p>\n\n\n\n<p>A properly functioning o-ring slides during reciprocating motion, aided by pressure-induced friction holding it in place. Spiral failure occurs when portions of the o-ring twist because of uneven frictional conditions. Pressure then pushes the twisted seal into a gap. This causes stress that creates cracks in a spiral pattern.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Leading Contributing Factors in Spiral Failure<\/h3>\n\n\n\n<p>Some conditions make it more likely for parts of the o-ring to slide. Other conditions cause them to roll. This rolling creates a twist that can lead to spiral failure.<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Speed of Stroke:<\/strong> &lt; 1 ft\/min encourages high running friction, mimicking break-out friction. At elevated temperatures (&gt; 100\u00b0F), failure can occur within a few hundred cycles.<\/li>\n\n\n\n<li><strong>Lack of Lubrication: <\/strong>Especially on long strokes &gt; 6&#8243;, dry surfaces increase wear and encourage twisting.<\/li>\n\n\n\n<li><strong>Pressure Differential and Direction:<\/strong> Spiral failures are most likely when <a href=\"https:\/\/www.globaloring.com\/o-ring-pressure-ratings\/\" data-type=\"link\" data-id=\"https:\/\/www.globaloring.com\/o-ring-pressure-ratings\/\" target=\"_blank\" rel=\"noreferrer noopener\">pressure<\/a> and friction act in the same direction.<\/li>\n\n\n\n<li><strong>Excessive Squeeze:<\/strong> Greater than 0.017&#8243; on a 0.210&#8243; cross-section increases rolling forces.<\/li>\n\n\n\n<li><strong>Groove Geometry: <\/strong>Poorly supported split grooves offer inadequate holding force.<\/li>\n\n\n\n<li><strong>Operating Temperature: <\/strong>High temperatures degrade lubricants, increase elastomer softness, and expand clearances.<\/li>\n\n\n\n<li><strong>Stroke Length:<\/strong> Longer strokes amplify side loads and eccentricities.<\/li>\n\n\n\n<li><strong>Surface Finish:<\/strong> Scratches or uneven finishes can produce inconsistent friction, which increases torsional stress.<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Preventing Spiral Failure<\/h3>\n\n\n\n<p>These practices help control friction, motion, and support in the groove. This control reduces the chances of an o-ring twisting and failing in a spiral pattern.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Maintain Stroke Speeds:<\/strong> &gt; 1 ft\/min when possible, especially in low differential pressure environments.<\/li>\n\n\n\n<li><strong>Lubricate Adequately: <\/strong>Use greases that don&#8217;t evaporate or dry out at operating temperature. Consider plated surfaces to reduce friction.<\/li>\n\n\n\n<li><strong>Control Groove Geometry: <\/strong>Prefer square grooves and ensure that split grooves maintain effective holding forces across all seal contact areas.<\/li>\n\n\n\n<li><strong>Reduce Squeeze to Industry-Recommended Levels:<\/strong> This is especially important for long-stroke designs.<\/li>\n\n\n\n<li><strong>Limit Stroke Lengths:<\/strong> &gt; 12&#8243; unless guided or supported to mitigate bending and side loads.<\/li>\n\n\n\n<li><strong>Improve Surface Finishes: <\/strong>Uniform, smooth metal surfaces minimize the chance of torsional misbehavior.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p>Understanding the mechanisms of spiral and extrusion failures early in the design phase is crucial. This understanding allows you to implement robust design fundamentals that prevent these failures.<\/p>\n\n\n\n<p>For extrusion, this means managing pressure, gaps, and material hardness. Spiral failure involves stroke velocity, lubrication, squeeze, and groove geometry. By addressing these factors during the design phase, you can avoid downstream issues that jeopardize system integrity.<\/p>\n\n\n\n<p>Applying these principles significantly improves seal life and performance, aligning with the broader design objectives of reliability and maintainability in sealed systems.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Q&amp;A: Extrusion and Spiral Failure in O-Ring Design<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">What causes o-ring extrusion in sealing applications?<\/h3>\n\n\n\n<p>O-Ring extrusion occurs when system pressure forces elastomers into the clearance gap between mating components. When pressure, clearance, or material limits are exceeded, the o-ring deforms, shears, and begins to nibble, leading to premature seal damage and eventual leakage.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How can o-ring extrusion be prevented in high-pressure systems?<\/h3>\n\n\n\n<p>O-Ring extrusion is prevented by limiting clearance gaps, increasing elastomer hardness, and adding backup rings to support the seal under pressure. These design choices restrict the material flow into the clearance gap and stabilize the o-ring during dynamic conditions.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What is spiral failure in o-rings?<\/h3>\n\n\n\n<p>Spiral failure is a dynamic failure mode where uneven friction during reciprocating motion causes the o-ring to twist and tear in a corkscrew pattern. The seal may continue functioning briefly, but progressive twisting eventually leads to rupture. <\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What operating conditions contribute to o-ring spiral failure?<\/h3>\n\n\n\n<p>Spiral failure is most likely at low stroke speeds, high temperatures, long stroke lengths, poor lubrication, excessive squeeze, and inconsistent surface finishes. These conditions promote rolling instead of sliding, allowing the o-ring to twist under pressure.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How can spiral failure be prevented in reciprocating seals?<\/h3>\n\n\n\n<p>Spiral failure is prevented by maintaining adequate stroke speeds, applying stable lubrication, reducing excessive squeeze, optimizing groove geometry, and improving surface finishes. These practices keep friction uniform and prevent seal twisting.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Summary Introduction A sealing system&#8217;s design must account for common o-ring failure modes that compromise long-term reliability. Extrusion and spiral failure are crucial. They often happen quietly during operations. However, they can cause sudden, serious leaks when the seal fails to work. Extrusion typically occurs when pressure and clearance conditions exceed the limits of the <a href=\"https:\/\/www.globaloring.com\/blog\/preventing-o-ring-extrusion-and-spiral-failure\/\">[&hellip;]<\/a><\/p>\n","protected":false},"author":28246,"featured_media":343659,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[1427],"tags":[34727,29421,33019],"class_list":["post-343502","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-quality","tag-o-ring-performance","tag-o-ring-quality","tag-service"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/posts\/343502","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/users\/28246"}],"replies":[{"embeddable":true,"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/comments?post=343502"}],"version-history":[{"count":6,"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/posts\/343502\/revisions"}],"predecessor-version":[{"id":424295,"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/posts\/343502\/revisions\/424295"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/media\/343659"}],"wp:attachment":[{"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/media?parent=343502"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/categories?post=343502"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.globaloring.com\/wp-json\/wp\/v2\/tags?post=343502"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}