{"id":35099,"date":"2025-05-21T12:52:18","date_gmt":"2025-05-21T11:52:18","guid":{"rendered":"https:\/\/www.hawkins.biz\/?post_type=insight&#038;p=35099"},"modified":"2025-08-06T16:50:08","modified_gmt":"2025-08-06T15:50:08","slug":"push-fit-fittings-and-statistical-analysis","status":"publish","type":"insight","link":"https:\/\/www.hawkins.biz\/insight\/push-fit-fittings-and-statistical-analysis\/","title":{"rendered":"Push-Fit Fittings and Statistical Analysis"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"35099\" class=\"elementor elementor-35099\" data-elementor-post-type=\"insight\">\n\t\t\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-d865d26 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"90009\" data-id=\"d865d26\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-57003cb\" data-eae-slider=\"76555\" data-id=\"57003cb\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-a7e512f elementor-widget elementor-widget-text-editor\" data-id=\"a7e512f\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Hawkins investigates numerous escapes of water involving push-fit fittings, where it is important to determine whether the parts were defective or whether there were workmanship issues.<\/p><p>Push-fit fittings, sometimes referred to as push-to-connect fittings or quick-connect fittings, mark a significant improvement in the world of connection technologies for pipes and tubing. Their ease of use has quickly seen them rise in prominence, becoming a cornerstone in fields as diverse as modern plumbing, advanced manufacturing, and an array of DIY projects. It is no wonder then that plastic push-fit fittings have become a common feature in many domestic water installations. They allow plumbers to form a joint by simply pushing a pipe fully into the fitting; a retention feature within the fitting then ensures the pipe remains firmly attached.<\/p><p>Compared with other types of plumbing joints, push-fit fittings bring several benefits:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-afdb9a3 elementor-align-left elementor-icon-list--layout-traditional elementor-list-item-link-full_width elementor-widget elementor-widget-icon-list\" data-id=\"afdb9a3\" data-element_type=\"widget\" data-widget_type=\"icon-list.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<ul class=\"elementor-icon-list-items\">\n\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"8.305\" height=\"15.142\" viewBox=\"0 0 8.305 15.142\"><path id=\"Path_185\" data-name=\"Path 185\" d=\"M0,0,5.536,7.572,0,15.143H2.768L8.3,7.572,2.768,0Z\" transform=\"translate(0 0)\" fill=\"#007aa3\" opacity=\"0.998\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">The joints are easy to form without the use of specialised tooling.<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"8.305\" height=\"15.142\" viewBox=\"0 0 8.305 15.142\"><path id=\"Path_185\" data-name=\"Path 185\" d=\"M0,0,5.536,7.572,0,15.143H2.768L8.3,7.572,2.768,0Z\" transform=\"translate(0 0)\" fill=\"#007aa3\" opacity=\"0.998\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">The joints are effective instantly; no need to wait for soldering material to cool down or for a chemical bond to form.<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"8.305\" height=\"15.142\" viewBox=\"0 0 8.305 15.142\"><path id=\"Path_185\" data-name=\"Path 185\" d=\"M0,0,5.536,7.572,0,15.143H2.768L8.3,7.572,2.768,0Z\" transform=\"translate(0 0)\" fill=\"#007aa3\" opacity=\"0.998\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">The ease with which the joints can be taken apart and reused (ease of disassembly and reuse is a particularly attractive feature when buildings have to be altered or when the work is done in stages).<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t<\/ul>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-a00e282 elementor-widget elementor-widget-text-editor\" data-id=\"a00e282\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>As a result of their versatility, push-fit fittings have proved popular with both tradespeople and DIY enthusiasts alike but, conversely, are becoming an increasing concern to the UK insurance industry.\u00a0 An online article published in April 2023 by Copper Sustainability Partnership<a href=\"#reference\" name=\"_ftnref1\">\u00b9<\/a> states \u201c<em>new research cites plastic push fittings as <\/em>[a]\u00a0<em>leading cause of water leaks. <\/em>[\u2026] <em>In the past eight years alone, the total cost of escape of water claims has nearly doubled, with these claims currently costing UK insurers \u00a32.5 million a day.<\/em>\u201d<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-0131ac1 elementor-widget elementor-widget-image\" data-id=\"0131ac1\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"567\" height=\"375\" src=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture2.jpg\" class=\"attachment-large size-large wp-image-35101\" alt=\"\" srcset=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture2.jpg 567w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture2-300x198.jpg 300w\" sizes=\"(max-width: 567px) 100vw, 567px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Versatile use of plastic push-fit fittings to connect copper pipes<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-953765e elementor-widget elementor-widget-text-editor\" data-id=\"953765e\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h4><span style=\"color: #0a527a;\">How D<\/span><span style=\"color: #0a527a; background-color: initial;\">oes a Push-Fit Fitting Work?<\/span><\/h4><p><span data-contrast=\"auto\">Push-fit fittings are well suited for use with plastic pipes, but they can also be used with copper pipes.\u00a0<\/span> <span data-contrast=\"auto\">It\u202fis not uncommon for a plumber to use a push-fit fitting to connect a copper pipe on an existing system to a new plastic one.\u00a0<\/span> <span data-contrast=\"auto\">The fittings can be made from plastic, which is not prone to corrosion.\u00a0<\/span> <span data-contrast=\"auto\">Experience has shown they are suitable for use with either slightly acidic or alkaline water, and fittings able to sustain temperatures above 100\u00b0C for a short duration of time (a few hours) are commonly available.\u00a0 They can therefore be used on mains cold water, domestic hot water and central heating systems.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p><p><span data-contrast=\"auto\">Manufacturers are marketing a broad range of push-fit fittings with slightly different shapes and functions, but the fundamental concept is based on three main elements:\u00a0<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-473fbda elementor-align-left elementor-icon-list--layout-traditional elementor-list-item-link-full_width elementor-widget elementor-widget-icon-list\" data-id=\"473fbda\" data-element_type=\"widget\" data-widget_type=\"icon-list.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<ul class=\"elementor-icon-list-items\">\n\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"8.305\" height=\"15.142\" viewBox=\"0 0 8.305 15.142\"><path id=\"Path_185\" data-name=\"Path 185\" d=\"M0,0,5.536,7.572,0,15.143H2.768L8.3,7.572,2.768,0Z\" transform=\"translate(0 0)\" fill=\"#007aa3\" opacity=\"0.998\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">An O-ring to provide a waterproof seal<\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"8.305\" height=\"15.142\" viewBox=\"0 0 8.305 15.142\"><path id=\"Path_185\" data-name=\"Path 185\" d=\"M0,0,5.536,7.572,0,15.143H2.768L8.3,7.572,2.768,0Z\" transform=\"translate(0 0)\" fill=\"#007aa3\" opacity=\"0.998\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">A retaining device to prevent the pipe from being pulled out of the fitting unintentionally (the\u202fretaining device is often a collet fitted with inward-pointing teeth). <\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t\t\t<li class=\"elementor-icon-list-item\">\n\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-icon\">\n\t\t\t\t\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"8.305\" height=\"15.142\" viewBox=\"0 0 8.305 15.142\"><path id=\"Path_185\" data-name=\"Path 185\" d=\"M0,0,5.536,7.572,0,15.143H2.768L8.3,7.572,2.768,0Z\" transform=\"translate(0 0)\" fill=\"#007aa3\" opacity=\"0.998\"><\/path><\/svg>\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-icon-list-text\">A mechanism, typically a nut, that keeps the retaining device in position but also allows the disassembly of the joint (following disassembly, both the pipe and the fitting could be re-used provided they are not damaged). <\/span>\n\t\t\t\t\t\t\t\t\t<\/li>\n\t\t\t\t\t\t<\/ul>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-63a4296 elementor-widget elementor-widget-image\" data-id=\"63a4296\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"800\" height=\"527\" src=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture3.jpg\" class=\"attachment-large size-large wp-image-35102\" alt=\"\" srcset=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture3.jpg 1024w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture3-300x197.jpg 300w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture3-768x506.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Push-fit fittings are available in a range of types and sizes<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-91041ba elementor-widget elementor-widget-text-editor\" data-id=\"91041ba\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>When a pipe is inserted fully into the fitting, the O-ring is pressed between the pipe\u2019s outer diameter and the inside of the main body\u2019s socket to create a watertight seal. The collet teeth are designed to allow the pipe to pass into the socket, but bite into the outside of the pipe and resist its extraction from the socket.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3d3ff55 elementor-widget elementor-widget-image\" data-id=\"3d3ff55\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"800\" height=\"543\" src=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture4.jpg\" class=\"attachment-large size-large wp-image-35103\" alt=\"\" srcset=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture4.jpg 944w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture4-300x204.jpg 300w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture4-768x521.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Cross-section of a push-fit fitting<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d6422fc elementor-widget elementor-widget-text-editor\" data-id=\"d6422fc\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><span class=\"TextRun SCXW85495071 BCX8\" lang=\"EN-GB\" xml:lang=\"EN-GB\" data-contrast=\"auto\"><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">The <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">harder <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">pipe is<\/span> <span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">being <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">forc<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">ed<\/span> <span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">out, <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">either from internal water pressure <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">or a pulling <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">action <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">on the pipe, <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the stronger the reacti<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">on<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> of the <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">nut<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> onto the collet and the stronger the <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">bite of the teeth<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> into the pipe<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.&nbsp;<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">A<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> push-fit<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> fitting\u2019s ability to withstand water pressure<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> or pull-out forces<\/span> <span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">is reliant<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> on the <\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\">nut<\/span><span class=\"NormalTextRun SCXW85495071 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> keeping the collet teeth tightly pressed onto the pipe.<\/span><\/span><span class=\"EOP SCXW85495071 BCX8\" data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">&nbsp;<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-e653e27 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"22471\" data-id=\"e653e27\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-cf762b0\" data-eae-slider=\"50051\" data-id=\"cf762b0\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-aa170f1 elementor-widget elementor-widget-image\" data-id=\"aa170f1\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"551\" src=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture5.png\" class=\"attachment-large size-large wp-image-35104\" alt=\"\" srcset=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture5.png 945w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture5-300x207.png 300w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture5-768x529.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Cross-section illustrating how a push-fit fitting resists the extraction of the pipe <\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-ad48195 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"31947\" data-id=\"ad48195\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-ba2297f\" data-eae-slider=\"58093\" data-id=\"ba2297f\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-2f2ad83 elementor-widget elementor-widget-text-editor\" data-id=\"2f2ad83\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h4><span style=\"background-color: initial;\" data-contrast=\"auto\"><span style=\"color: #0a527a;\">The Downside of Popularity<\/span><\/span><\/h4><p><span data-contrast=\"auto\">Due to their popularity, manufacturers produce millions of push-fit fittings every year. Despite rigorous quality controls being in place, given the large volume of products manufactured, the possibility of a defective part being supplied into the marketplace cannot be discounted.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p><p><span data-contrast=\"auto\">The fittings are installed across a wide range of properties with very different characteristics in terms of water pressure, temperature, and type of installation.\u00a0 The fittings, therefore, encounter a broad range of conditions in service.\u00a0 In some instances, these conditions could prove quite severe. For example, properties with higher water pressure or following maintenance work which has caused sudden water pressure variations can influence the reliability of the fittings. Although the \u201c<\/span><i><span data-contrast=\"auto\">Water Regulations Guide<\/span><\/i><span data-contrast=\"auto\">\u201d states that fittings should not be embedded in a wall or solid floor, Hawkins has come across push-fit fittings installed where they are hidden from view, either underground, under floors, or within walls.\u00a0 When fittings are concealed, escapes of water may take longer to become detectable and, consequently, cause more severe damage.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-6af55dd elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"21601\" data-id=\"6af55dd\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-41e824c\" data-eae-slider=\"19023\" data-id=\"41e824c\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-b820514 elementor-widget elementor-widget-image\" data-id=\"b820514\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"530\" src=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture6.jpg\" class=\"attachment-large size-large wp-image-35105\" alt=\"\" srcset=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture6.jpg 1025w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture6-300x199.jpg 300w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture6-768x509.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Push-fit fittings installed under a solid floor<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-057a7f9 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"81356\" data-id=\"057a7f9\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-2a87adc\" data-eae-slider=\"35414\" data-id=\"2a87adc\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-97e3cf4 elementor-widget elementor-widget-text-editor\" data-id=\"97e3cf4\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><span class=\"TextRun SCXW240633465 BCX8\" lang=\"EN-GB\" xml:lang=\"EN-GB\" data-contrast=\"auto\"><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Installation or m<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">anufacturing q<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">uality issues <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">can <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">have a <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">detrimental <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">effect on <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the reliability<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> of <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">a<\/span> <span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">push-fit <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">fitting<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> in service<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">&nbsp;<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">F<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">or example, <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">when a <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">fitting <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">is<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> re-assembled<\/span> <span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">on-site,<\/span> <span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">and <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the nut is not fully tightened<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> during the re-assembly process<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">&nbsp;<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Alternatively, <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">u<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">nder the influence of <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">repeated <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">pressure fluctuations (<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">e.g. <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">caused by <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">opening and closing <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">of <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">taps) or of a load sustained over a prolonged period, <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">force-resisting <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">capacity<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> of the thread<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">s<\/span> <span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">between the nut and the fitting <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">could <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">be <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">exceeded<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.&nbsp;<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">This result<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">s<\/span> <span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">in <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">nut<\/span> <span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">be<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">ing<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> pushed out<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> of its intended position<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.<\/span>&nbsp;<span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">The nut can then be displaced <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">relative<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> to the <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">main body<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> or detached <\/span><span class=\"NormalTextRun ContextualSpellingAndGrammarErrorV2Themed SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">from the <\/span><span class=\"NormalTextRun ContextualSpellingAndGrammarErrorV2Themed SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">main body<\/span><span class=\"NormalTextRun ContextualSpellingAndGrammarErrorV2Themed SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">,<\/span> <span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">to the point<\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> that the watertight seal between the pipe and the socket <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">is <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">broken and water <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">is <\/span><span class=\"NormalTextRun SCXW240633465 BCX8\" data-ccp-parastyle=\"Normal (Web)\">able to escape.<\/span><\/span><span class=\"EOP SCXW240633465 BCX8\" data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">&nbsp;<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-332b830 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"7753\" data-id=\"332b830\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-8f3cf5b\" data-eae-slider=\"31729\" data-id=\"8f3cf5b\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-f037340 elementor-widget elementor-widget-text-editor\" data-id=\"f037340\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h4><span style=\"background-color: initial;\" data-contrast=\"auto\"><span style=\"color: #0a527a;\">Narrowing Down the Possible Causes<\/span><\/span><\/h4><p><span data-contrast=\"auto\">The reliability of a fitting is a function of multiple processes, including product design, material selection, manufacture, assembly, installation, and testing on-site. Identifying the main process step responsible for a reliability\/quality issue is key to enabling rapid and cost-effective remedial actions. Problem solving methods, such as Six Sigma, provide a proven framework to identify the causes of quality related problems. Six Sigma uses a range of statistical tools to narrow down the possible causes and reduce subjective bias in the interpretation of data. <\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p><p><span data-contrast=\"auto\">One of these tools is the \u201c<\/span><i><span data-contrast=\"auto\">normal distribution<\/span><\/i><span data-contrast=\"auto\">\u201d. The normal distribution assumes that random and independent measurements of a given characteristic, such as mechanical strength, would be spread equally around an average value. <\/span><\/p><p><span data-contrast=\"auto\">This\u202fassumption is generally suitable for manufactured products due to the averaging effect of the many processes involved in their design and production. The spread of values would typically account for variations caused by product design, material properties, manufacturing capability, and measurement repeatability.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p><p><span data-contrast=\"auto\">Using data recorded on example fittings (exemplars) for a specific characteristic, a normal distribution can be used to predict where a defined percentage of fittings, usually 95% or 99.7%<a href=\"#references\">\u00b2<\/a><\/span><span data-contrast=\"auto\">, would be expected to be for that characteristic. These predictions can then be used to determine whether fittings that have failed in service (exhibits) differ from the \u2018<\/span><i><span data-contrast=\"auto\">norm<\/span><\/i><span data-contrast=\"auto\">\u2019.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6875877 elementor-widget elementor-widget-text-editor\" data-id=\"6875877\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h4><span style=\"background-color: initial;\" data-contrast=\"auto\"><span style=\"color: #0a527a;\">Case Study<\/span><\/span><\/h4><p>During an escape of water investigation, Hawkins\u2019 site inspection revealed that the nut of a push-fit fitting had been displaced and had allowed water to escape. The investigation confirmed that the failure was not the result of an installation issue but suggested instead that the mechanical strength of the fitting\u2019s nut might be less than expected. In this instance, the shape of the nut made it impractical to measure its mechanical strength directly. However, since the nut was made of \u2018nylon\u2019, a plastic material, the nut\u2019s mechanical strength was known to be proportional to the nylon\u2019s \u2018molecular weight\u2019 (i.e. the length of the nylon molecules in the nut). The longer the molecules, the more viscous and the stronger the material. Determining the molecular weight of the fitting was a more practical option to evaluate, by proxy, the mechanical strength of the nut.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-9b98148 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"70866\" data-id=\"9b98148\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-96fe915\" data-eae-slider=\"65847\" data-id=\"96fe915\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-9475af3 elementor-widget elementor-widget-image\" data-id=\"9475af3\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"664\" height=\"443\" src=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture7.jpg\" class=\"attachment-large size-large wp-image-35106\" alt=\"\" srcset=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture7.jpg 664w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture7-300x200.jpg 300w\" sizes=\"(max-width: 664px) 100vw, 664px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Escape of water at a displaced push-fit fitting nut<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-330fa88 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"15591\" data-id=\"330fa88\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-daf919d\" data-eae-slider=\"95862\" data-id=\"daf919d\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-cef3c59 elementor-widget elementor-widget-text-editor\" data-id=\"cef3c59\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><span class=\"TextRun SCXW94084093 BCX8\" lang=\"EN-GB\" xml:lang=\"EN-GB\" data-contrast=\"auto\"><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">The <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">molecular weight of <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">exhibit and <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">exemplar <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">nuts <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">was <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">assessed<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">. <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Multiple measurements were recorded on each <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">nut <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">to <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">reduce the contribution of measurement error<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">s<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">. <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">The fitting<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> involved <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">in th<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">is<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">connection<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">was a straight <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">coupler <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">with <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">two end<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> nuts<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">The molecular weight of <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">each <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">end <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">nut was <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">assessed<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> on <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">all <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">specimen<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">s<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">. <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">T<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">he exemplars\u2019 measurement data were grouped but<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the exhibit<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">s<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">\u2019<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">d<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">ata for the <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">two end<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> nuts<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">, <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">labelled <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Nut <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">A and <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Nut <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">B<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">, were <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">analysed <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">separately<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">The<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">\u202f<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">data <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">were <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">therefore <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">split <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">into <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">three groups<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">; values <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">for <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">(1) <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the exemplars, <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">(2) <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Nut<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> A, <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">and <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">(<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">3<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">) <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Nut<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">B. <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">Th<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">e <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">normal distribution <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">was used to <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">predict <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">the range<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">s<\/span> <span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">where <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">95% and 99.7% <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">(~100%) <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">of the <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">molecular weight <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">values <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">were <\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">expected to lie<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\"> for this type of fitting<\/span><span class=\"NormalTextRun SCXW94084093 BCX8\" data-ccp-parastyle=\"Normal (Web)\">.<\/span><\/span><span class=\"EOP SCXW94084093 BCX8\" data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-8c693e2 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"46212\" data-id=\"8c693e2\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-d409527\" data-eae-slider=\"49766\" data-id=\"d409527\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-ed34dde elementor-widget elementor-widget-image\" data-id=\"ed34dde\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"602\" height=\"395\" src=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture8.png\" class=\"attachment-large size-large wp-image-35107\" alt=\"\" srcset=\"https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture8.png 602w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture8-300x197.png 300w, https:\/\/www.hawkins.biz\/wp-content\/uploads\/2024\/12\/Picture8-600x395.png 600w\" sizes=\"(max-width: 602px) 100vw, 602px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Push-fit fittings molecular weight records (compared with the 95% and ~100% intervals predicted by the normal distribution) <\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-9751957 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"93592\" data-id=\"9751957\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-9d33e2a\" data-eae-slider=\"75999\" data-id=\"9d33e2a\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-1786ac3 elementor-widget elementor-widget-text-editor\" data-id=\"1786ac3\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>The data were normalised such that the molecular weight (thus the strength) of an average fitting had the numerical value of \u20181.00\u2019. The data showed that Nut B\u2019s values were less than \u20181.00\u2019 and, although they were at the low end of the 95% range, they were still comparable to typical values of molecular weight for exemplars. Therefore, Nut B\u2019s strength was expected to be broadly representative of this type of fitting. Nut\u202fB\u202fdid not fail in service. Consequently, there was no reason at this stage to question the suitability of the fitting\u2019s design or material selected.<\/p><p>Nut A\u2019s values were mostly outside of the ~100% range, i.e. they were unusually low for this type of fitting. From the analysis, we could infer that Nut A\u2019s mechanical strength was below that of the exemplars. Nut A failed in service and caused the escape of water. Because Nut\u202fA\u2019s values were mostly outside of the predicted ~100% range, Nut A\u2019s strength was not representative of that type of fitting. The statistics indicated that an unusual event or \u2018special cause\u2019, had occurred and caused the reduction of Nut A\u2019s mechanical strength. This observation pointed towards the possibility of a quality or assembly issue rather than a generic design or manufacturing issue.<\/p><p>The next step in the study would be to evaluate with the manufacturer the possible reasons for the reduced strength, such as an undetected quality issue with a batch of material or an incorrect part being used in the assembly. Remedial actions could then be identified to prevent re-occurrence of this issue.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-c90ac01 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"79085\" data-id=\"c90ac01\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-cbad31e\" data-eae-slider=\"5246\" data-id=\"cbad31e\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-32e9824 elementor-widget elementor-widget-text-editor\" data-id=\"32e9824\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<h4><span style=\"color: #0a527a;\">About The Author<\/span><\/h4><p><a href=\"https:\/\/www.hawkins.biz\/experts\/gerald-deshais\/\"><span data-contrast=\"none\">Gerald<\/span><\/a><span data-contrast=\"auto\"> spent 20 years in the aerospace industry where he gained extensive experience in the design and manufacture of complex products. Throughout his career, he has had a keen interest in continuously improving new products and has been involved in root cause analyses and solving materials, mechanical, or systems engineering problems.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p><p><span data-contrast=\"auto\">He is a Chartered Engineer with the Institution of Mechanical Engineers and is a certified Six Sigma practitioner. Six Sigma is a general problem-solving framework that can be applied across a range of products and issues. It is particularly well suited to identify root causes and address quality concerns with manufactured products.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335551550&quot;:6,&quot;335551620&quot;:6,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p><p><span data-contrast=\"auto\">If you would like to instruct a Hawkins engineer to determine the cause of a product failure, please\u202f<\/span><a href=\"https:\/\/www.hawkins.biz\/contact\/\"><span data-contrast=\"none\">get in touch<\/span><\/a><span data-contrast=\"auto\">.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-e716f61 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"39991\" data-id=\"e716f61\" data-element_type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-4ce7510\" data-eae-slider=\"71099\" data-id=\"4ce7510\" data-element_type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-de08653 elementor-widget elementor-widget-text-editor\" data-id=\"de08653\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><a href=\"#reference\">\u00b9 New research cites plastic push fittings as leading cause of water leaks \u2022 CuSP (cuspuk.com)<\/a><\/p><p><a href=\"#references\"><span class=\"TextRun SCXW215316896 BCX8\" lang=\"EN-GB\" xml:lang=\"EN-GB\" data-contrast=\"auto\"><span class=\"NormalTextRun SCXW215316896 BCX8\" data-ccp-parastyle=\"footnote text\">\u00b2 95% and 99.7% (~100%) correspond to <\/span><span class=\"NormalTextRun SCXW215316896 BCX8\" data-ccp-parastyle=\"footnote text\">standard\u00a0<\/span><span class=\"NormalTextRun SCXW215316896 BCX8\" data-ccp-parastyle=\"footnote text\">statistical intervals\u00a0<\/span><span class=\"NormalTextRun SCXW215316896 BCX8\" data-ccp-parastyle=\"footnote text\">described as being\u00a0<\/span><span class=\"NormalTextRun SCXW215316896 BCX8\" data-ccp-parastyle=\"footnote text\">four or six standard deviations\u2019 wide, respectively.\u00a0 A standard deviation is a statistical measure of how far data are from the average.<\/span><\/span><\/a><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Hawkins investigates numerous escapes of water involving push-fit fittings, where it is important to determine whether the parts were defective or whether there were workmanship issues.  <\/p>\n","protected":false},"featured_media":35100,"parent":0,"template":"","insight_category":[],"experties":[65,68],"class_list":["post-35099","insight","type-insight","status-publish","has-post-thumbnail","hentry","experties-engineering","experties-materials-chemistry-biology"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Push-Fit Fittings: Failures &amp; Statistical Forensics<\/title>\n<meta name=\"description\" content=\"Understand how forensic engineers use statistical tools to investigate water leaks caused by push-fit fittings and assess manufacturing defects.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" 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