TITLE: Anaerobic  (vinyl) tent maintenance
AUTHORS: Eva Petrova, Roey Angel

[DESCRIPTION]
<div class = "text-blocks"><div class = "text-block"><span>The </span><a href="https://coylab.com/products/anaerobic-chambers/vinyl-anaerobic-chambers/" style = "text-decoration:underline;color:blue;cursor:pointer;"><span style = ":;">Coy vinyl anaerobic chambre</span></a><span> is a special device that is consructed by a purpose to create and maintain anaerobic environment. It is made from flexible PVC vinyl supported by tubular aluminum frame. The chambre is a totally sealed unit except two entry ports: the equipment entry port and the airlock. </span></div><div class = "text-block"><span style = "font-weight:bold;">Airlock</span><span> is used to pass items between the chambre and the outside environment without disrupting the chamber's anaerobic athmosphere. For this purpose an automatic program (P1) consisting of three evacuation and three filling steps (two with N2 and last one with gas mix) was established. </span></div><div class = "text-block">Remember: </div><div class = "text-block">A) Light objects like towels will be flying or slightly moving in an Airlock during the procedure because of an over- and down-pressure changes. Be carefull about a staff you are putting in, protect it from a damage.</div><div class = "text-block">B) Everything that is tightly closed (bottles with media or chemicals, tubes etc.) has to be made anoxic before putting inside. Also consumables that are pre-packed (sterile serological pipettes, tips, Petri dishes) will still keep some oxygen after the Air-lock procedure. In some cases it is useful to make a small holes into packaging before to improve speed of gases exchange but it will loss the sterility.</div><div class = "text-block"><span>Lab personnel access the chambre to perform their operations through </span><span style = "font-weight:bold;">glove ports</span><span>. It is in favour of hygiene to wear one extra single-use gloves (nitrile, cotton or any others) under.</span></div><div class = "text-block"><span>Anaerobic athmosphere inside the ten is created usually by nitrogen as innert background gas (aka </span><span style = "font-weight:bold;">purge gas</span><span>) and by the </span><span style = "font-weight:bold;">hydrogen gas mix</span><span> depending on the experimental demands (usually mix of N</span><span style = "vertical-align:sub;">2</span><span>, H</span><span style = "vertical-align:sub;">2</span><span> and if needed CO</span><span style = "vertical-align:sub;">2</span><span>). However, the hydrogen concentration inside the tent must be always kept under 5% unless the gas mixture may be explosive.  4% of hydrogen is an optimal concentration that is non-flamable and still provides enough hydrogen for oxygen removal. In our anaerobic chambre gas mixture N2/H2 (95%/5% respectively) is used.</span></div></div>

[STEPS]
?. [Preventive maintenance - once a week]
rejuvenate the catalyst (bake it in an oven at 125 - 200°C for 2 hours)rejuvenate the desicant (bake it in an oven at 125 - 200°C for 2 hours)refresh hydrogen levels (let 1/4 of atmosphere volume off from a tent and then refill it with 95%N2/5%H2 gas mixture)clean the airlock seals (use wet sponge possibly soaked with soap or mild detergent, let it dried)clean the chamber and disinfect if neccesary (wash the desk with 1,5% chlorine bleach solution, wipe)check the moisture trap on the vacuum pump and drain any visible water collected therecheck the gas level/pressure in the bottles (approx. 40 psi (276 kPa))check the tube comming out from the large dehumidifier for moisture/water and pour it away, but leave some water inside the tube to not allow air comes into the device
?. [Preventive maintenance - once a month]
check the chamber for leakscheck both gas lines for leaksgrease the airlock door push pinscheck the airlock seal to make sure the lip of the seal collapses all around the door opening
?. [Preventive maintenance - once a year]
replace catalyst in HSR column and in Stack-Pakscalibrate sensors of CAM 12 (send them to Accela company)