Re: [omi] Day swich we are going 2 trie saterdays

On Sat, Mar 2, 2013 at 1:03 AM, Jonoakland <bayopensourcehardware(a)gmail.com> wrote: I won't be able to make it, but the oxy-acetylene cutter arrived. I'll try to remember to put it in sudo room so you can use it this coming saturday. I read up on instructions and safety of oxy-acetylene cutters, and there are some safety issues we need to be aware of. The most important issue is this: If the equipment is not operated correctly, the oxygen and acetylene gasses can become mixed in the hoses or in the gas cylinders. If subsequently ignited, this can cause an explosion big enough to take out all of OMI and a good chunk of the building. I have attached a short pdf with safety guidelines, and you should all read it very carefully. There will be a test. As explained in the pdf, there are two types of safety check valves. 1. Normal check valves that avoid gas flow in the wrong direction and thus avoids mixing of the gasses. 2. Flashback arrestors that prevent flames from moving through. This is seen as a higher level of safety than just having check valves, and they are usually sold as combination check valves and flashback arrestors. We have only the normal check valves. Flashback-arresting check valves cost $40 including shipping on ebay. My friend from Denmark looked at my like I was crazy when I told him we don't have flashback arrestors. I don't know what to think. Additionally, we haven't tested if our check valves still work (they look old). The procedure for testing check valves is included in the instructions pdf on page 9 under maintenance. We DEFINITELY need to run through this procedure before using the torch. One last thing: There appears to be something that looks like grease in some areas of the new cutting torch. This is a big no-no. Hopefully it's some kind of non-flammable grease, but I don't know if I trust it, coming from ebay. We should try to light it on fire to make sure. -- Marc Juul