<html><body><div style="font-family: arial,helvetica,sans-serif; font-size: 14pt; color: #000000"><div>Hi Tyler,</div><div><br data-mce-bogus="1"></div><div>I will not be able to get to this until October or maybe later. One thing that might not be clear though is that the construction of the RICH system is considered complete. If it needs to be altered, than any JLAB DA can do this. The DA for construction is not "The DA" for the life of the system. My suggestion is for you all to find a Hall B DA to take care of this issue in a more timely manner than I can. I will be happy to help that DA when possible.</div><div><br data-mce-bogus="1"></div><div>Sorry for the inconvenience</div><div><br></div><div data-marker="__SIG_PRE__">David Meekins<br>Staff Scientist<br>Thomas Jefferson National Accelerator Facility<br>12000 Jefferson Ave<br>Newport News Va. 23606<br><br>Office: 757-269-5434<br>Cell: 757-968-9076</div><br><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"Tyler Lemon" <tlemon@jlab.org><br><b>To: </b>"Bob Miller" <rmiller@jlab.org>, "David Meekins" <meekins@jlab.org><br><b>Cc: </b>"dsg-rich" <dsg-rich@jlab.org><br><b>Sent: </b>Thursday, September 7, 2017 8:07:20 AM<br><b>Subject: </b>Back-up N2 system components for RICH<br></div><br><div data-marker="__QUOTED_TEXT__"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000"><div>Hello Bob and Dave,<br></div><br><div>For RICH, the nitrogen purge is used to keep the aerogel tiles inside RICH in a low humidity environment. If the aerogel is damaged due to moisture absorption, RICH will not be able to operate properly.<br></div><br><div>Could we arrange for an approved regulator and components to be on hand to be able to switch to a nitrogen dewar or bottle for RICH in Hall B in the event that Hall B's main nitrogen supply goes down?<br></div><br><div>As system owner and Design Authority for RICH, we would need to get the list of components and the approval from you to use this back-up system.<br></div><br><div>Please let us know how we should proceed in order to get this back-up nitrogen system ready for RICH.<br></div><br><div>Best regards,<br></div><div>Tyler</div></div><br></div></div></body></html>