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<td><a href="https://misportal.jlab.org/ll/index.jsf?function=view&lessonId=790">2K Return Pressure Testing Pipe Plug Ejection</a></td>
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<h2 style="white-space:nowrap">Statement of Lessons Learned</h2>
<pre>Copies of referenced documents are available under “Attachments” on Lessons Learned page.
Ensure you fully understand how to install and operate pressure testing equipment before it is used. Information that would have helped avoid this incident was only discovered after talking to the president of the company from which the equipment was purchased.</pre>
<h2 style="white-space:nowrap">Discussion of Activities</h2>
<pre>On January 15, 2014, the Cryogenic Department performed a pneumatic test of FRIB transfer line prototype welded assemblies. The test took place within a designated fabrication area of the TEDF Building in accordance with Work Control Document – CRY-14-34426-TOSP. A 10 NPS SS type 304 (2K return) line was the last item tested that day.
The line was plugged, at both ends, with a standard design “D” Type plug that was supposed to expand against the inner pipe wall with pressure. These D-plugs were specially designed and factory tested to 300 psig from COB Industries, Incorporated (COBII). (See the “2K Return Pressure Test Diagram within “Attachments” for details.)
After inserting the plugs, a large adjustable wrench was used to provide a preload with as much force as could be mustered without additional mechanical advantage. Non-essential personnel were evacuated from the test area. Pressure was then applied from a regulated nitrogen gas supply.
When the pressure reading reached approximately 12 psig, one of the plugs ejected from the end of the pipe and slammed into the side of a 3-foot diameter vacuum shell. (This had been positioned specifically to limit damage, in case the plug ejected.) The other plug was held in place by a plate primarily intended to restrain the bellows in the line from over extending.
The ejected plug was replaced with a welded cap and the test was completed without further safety related incident.</pre>
<h2 style="white-space:nowrap">Analysis</h2>
<pre>There was no installation procedure that accompanied the plugs. Without the proper torque, the grips did not ‘bite’ into the pipe wall and the additional wedging action due to pressure, particularly at the lower end, was not enough to overcome the translational forces that ultimately pushed the plug out of the pipe--there were no ridges felt within the pipe end after this occurrence.
These plugs are limited to fit pipe diameters having tolerances of ± 0.035” according to the literature that did come with them. The pipe end where the plug ejected was later measured to be + 0.069”, -0.095”.
An installation video, later provided by the COBII president, stated that these plugs are not recommended for pneumatic testing as this can unleash significantly higher stored energy.</pre>
<h2 style="white-space:nowrap">Recommended Actions</h2>
<pre>Below are the consequences of the above event. They are provided for information and discussion purposes only.
• Use a suitable plug for prototype sections.
• Use an 18” wrench with a 3-foot cheater bar to get adequate initial torque onto the large end plugs in order for them to work properly (according the COBII rep.).
• Restrain all plugs with an end plate, chain or other means so that they pose a low risk if they don’t seal. .
• Ensure plug and pipe diameters are within manufacturer’s tolerances.</pre>
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<h2>Comments</h2>
<h5 style="white-space:nowrap">2/6/2014 1:34:21 PM by Bailey, Mary Jo</h5>
<pre>Submitted to those with current •SAF130B: PRESSURE SYSTEMS SAFETY DESIGN AUTHORITY Training</pre>
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<legend>Summary</legend>
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<td class="label" nowrap>Lesson ID:</td>
<td class="dataval">790</td>
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<td class="label" nowrap>Status:</td>
<td class="dataval">OK</td>
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<td class="label" nowrap>Doc ID:</td>
<td class="dataval">2014-JLAB-790</td>
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<td class="label" nowrap>Priority:</td>
<td class="dataval">Info</td>
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<td class="label" nowrap>Safety Related:</td>
<td class="dataval">YES</td>
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<td class="label" nowrap>Originator:</td>
<td class="dataval">Bailey, Mary Jo</td>
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<td class="label" nowrap>Issued:</td>
<td class="dataval">2/4/2014 4:01:44 PM</td>
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<td class="label" nowrap>Approved By:</td>
<td class="dataval">Bailey, Mary Jo</td>
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<td class="label" nowrap>Approved On:</td>
<td class="dataval">2/6/2014 1:34:21 PM</td>
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<td class="label">Source:</td>
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OTHER
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<td class="label" nowrap>Location:</td>
<td class="dataval">TJNAF</td>
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<td class="label" nowrap>Cost Savings:</td>
<td class="dataval"></td>
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<td class="label" nowrap>Contact:</td>
<td class="dataval">Kelly Dixon, Jefferson Lab, Cryogenic Department, 757-269-6285</td>
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<td class="label" nowrap>Queued Emails:</td>
<td class="dataval">0</td>
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<td class="label" nowrap>Sent Emails:</td>
<td class="dataval">0</td>
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<td class="label" nowrap>Viewings:</td>
<td class="dataval">97 times</td>
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<legend>Attachments</legend>
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<ul class="lesson_attribute_listing">
<li><a target="_blank" href="https://misportal.jlab.org/ll/downloadAttachment?attachmentId=2740">M:\wcd\LessonsLearned\Pressure Sys\2K Return Pressure Test Diagram.pdf</a></li>
<li><a target="_blank" href="downloadAttachment?attachmentId=2741">M:\wcd\LessonsLearned\Pressure Sys\2K Return Pressure Test TOSP.pdf</a></li>
<li><a target="_blank" href="downloadAttachment?attachmentId=2742">M:\wcd\LessonsLearned\Pressure Sys\2K Return Pressure Test-Notes.pdf</a></li>
<li><a target="_blank" href="downloadAttachment?attachmentId=2743">M:\wcd\LessonsLearned\Pressure Sys\2K Return Pressure Test THA.pdf</a></li>
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<legend>Hazard Issues</legend>
<ul class="lesson_attribute_listing">
<li>Pressure Systems</li>
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<legend>Skills</legend>
<ul class="lesson_attribute_listing">
<li>SAF130B: PRESSURE SYSTEMS SAFETY DESIGN AUTHORITY</li>
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<legend>Distribution/Notification</legend>
<ul class="lesson_attribute_listing">
<li>*Division Safety Officers (DSOs)</li>
<li>*Safety Wardens</li>
<li>*DOE Notification</li>
<li>*ESH&Q Liaisons</li>
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