[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:04.70,0:00:09.84,Default,,0000,0000,0000,,[SOUND] Before looking closer at torch\Nhandles, we need to explain a few terms
Dialogue: 0,0:00:09.84,0:00:14.91,Default,,0000,0000,0000,,and understand some of the hazards\Nassociated with oxy-fuel equipment.
Dialogue: 0,0:00:14.91,0:00:19.29,Default,,0000,0000,0000,,The terms are reverse flow, flashback,
Dialogue: 0,0:00:19.29,0:00:23.30,Default,,0000,0000,0000,,backfire, and sustained backfire.
Dialogue: 0,0:00:23.30,0:00:28.61,Default,,0000,0000,0000,,Reverse flow is when either the oxygen\Nenters the fuel gas side of the system,
Dialogue: 0,0:00:28.61,0:00:32.23,Default,,0000,0000,0000,,or the fuel gas enters\Nthe oxygen side of the system.
Dialogue: 0,0:00:32.23,0:00:36.27,Default,,0000,0000,0000,,This occurs when there's\Na restriction of one of the gases or
Dialogue: 0,0:00:36.27,0:00:38.10,Default,,0000,0000,0000,,an imbalance of pressure.
Dialogue: 0,0:00:38.10,0:00:41.53,Default,,0000,0000,0000,,This can be caused by a clogged or\Nblocked tip, or
Dialogue: 0,0:00:41.53,0:00:44.97,Default,,0000,0000,0000,,allowing one of your\Ncylinders to run out of gas.
Dialogue: 0,0:00:44.97,0:00:49.67,Default,,0000,0000,0000,,If a reverse flow condition exists,\Na flashback can occur.
Dialogue: 0,0:00:49.67,0:00:54.74,Default,,0000,0000,0000,,Flashback is the retun of a flame\Nthrough the torch into the hose and
Dialogue: 0,0:00:54.74,0:00:56.74,Default,,0000,0000,0000,,even into the regulator.
Dialogue: 0,0:00:56.74,0:00:59.22,Default,,0000,0000,0000,,It could potentially reach the cylinder.
Dialogue: 0,0:00:59.22,0:01:03.84,Default,,0000,0000,0000,,This condition could cause an explosion\Nanywhere within the system.
Dialogue: 0,0:01:03.84,0:01:08.40,Default,,0000,0000,0000,,Flashback arrestors are designed to\Nprevent the flame from traveling
Dialogue: 0,0:01:08.40,0:01:10.64,Default,,0000,0000,0000,,beyond the point of the arrester.
Dialogue: 0,0:01:10.64,0:01:15.19,Default,,0000,0000,0000,,Flashback arrestors contain\Na sintered filter which prevents
Dialogue: 0,0:01:15.19,0:01:18.80,Default,,0000,0000,0000,,a flame from passing\Nthrough the filter element.
Dialogue: 0,0:01:18.80,0:01:22.89,Default,,0000,0000,0000,,Backfire is the return of\Na flame back into the torch,
Dialogue: 0,0:01:22.89,0:01:25.45,Default,,0000,0000,0000,,which produces a popping sound.
Dialogue: 0,0:01:25.45,0:01:29.44,Default,,0000,0000,0000,,The flame will either extinguish or\Nreignite at the tip.
Dialogue: 0,0:01:29.44,0:01:33.76,Default,,0000,0000,0000,,This is normally the result of\Naccidentally bumping the tip against
Dialogue: 0,0:01:33.76,0:01:37.92,Default,,0000,0000,0000,,the workpiece, operating the tip\Ntoo close to the workpiece, or
Dialogue: 0,0:01:37.92,0:01:40.51,Default,,0000,0000,0000,,allowing the tip to become overheated.
Dialogue: 0,0:01:40.51,0:01:43.55,Default,,0000,0000,0000,,The last event is a sustained backfire.
Dialogue: 0,0:01:43.55,0:01:48.19,Default,,0000,0000,0000,,This is when a backfire occurs and\Ncontinues burning in the torch.
Dialogue: 0,0:01:48.19,0:01:52.56,Default,,0000,0000,0000,,This condition may be accompanied\Nby a popping sound followed by
Dialogue: 0,0:01:52.56,0:01:55.48,Default,,0000,0000,0000,,a continuous whistling or hissing sound.
Dialogue: 0,0:01:55.48,0:02:00.32,Default,,0000,0000,0000,,Some of the causes for this are improperly\Nmaintained equipment, overheating of
Dialogue: 0,0:02:00.32,0:02:04.95,Default,,0000,0000,0000,,the equipment, or improper pressure\Nsettings for the equipment being used.
Dialogue: 0,0:02:04.95,0:02:08.49,Default,,0000,0000,0000,,[SOUND]\N>> This is a typical Victor handle.
Dialogue: 0,0:02:08.49,0:02:10.16,Default,,0000,0000,0000,,On most of our popular handles,
Dialogue: 0,0:02:10.16,0:02:14.61,Default,,0000,0000,0000,,you'll notice there'll be a built-in flash\Narrester and a built-in check valve.
Dialogue: 0,0:02:14.61,0:02:18.47,Default,,0000,0000,0000,,One of the misconceptions in our industry\Nis a check valve will stop a fire,
Dialogue: 0,0:02:18.47,0:02:19.46,Default,,0000,0000,0000,,that's not true.
Dialogue: 0,0:02:19.46,0:02:23.76,Default,,0000,0000,0000,,What a check valve is designed to do is\Nto stop the gas from getting on the wrong
Dialogue: 0,0:02:23.76,0:02:24.85,Default,,0000,0000,0000,,side of the torch.
Dialogue: 0,0:02:24.85,0:02:28.36,Default,,0000,0000,0000,,A flash arrester is\Ndesigned to stop a fire.
Dialogue: 0,0:02:28.36,0:02:33.27,Default,,0000,0000,0000,,A flash arrester will stop the fire\Nfrom advancing further up the system.
Dialogue: 0,0:02:33.27,0:02:37.64,Default,,0000,0000,0000,,>> And if your torch doesn't have\Na check valve or flashback arrestor it,
Dialogue: 0,0:02:37.64,0:02:41.58,Default,,0000,0000,0000,,we strongly recommend that you\Ninstall them before operating.
Dialogue: 0,0:02:41.58,0:02:44.63,Default,,0000,0000,0000,,>> And if you do, you may have heard\Nit there, you put them at the torch or
Dialogue: 0,0:02:44.63,0:02:46.02,Default,,0000,0000,0000,,the regulator or both places.
Dialogue: 0,0:02:46.02,0:02:49.33,Default,,0000,0000,0000,,And if you decide to put them at\Nthe regulator and at the torch,
Dialogue: 0,0:02:49.33,0:02:52.96,Default,,0000,0000,0000,,make sure you check with\Nthe manufacturer's data sheet to make sure
Dialogue: 0,0:02:52.96,0:02:55.16,Default,,0000,0000,0000,,it will not restrict flow to your torch.
Dialogue: 0,0:02:55.16,0:02:58.86,Default,,0000,0000,0000,,[SOUND]\N>> To reiterate what Tim said,
Dialogue: 0,0:02:58.86,0:03:04.25,Default,,0000,0000,0000,,the best rule is to have safety devices\Nas close to operation as possible.
Dialogue: 0,0:03:04.25,0:03:08.14,Default,,0000,0000,0000,,This means incorporating check valves and\Nflashback arrestors into the torch.
Dialogue: 0,0:03:08.14,0:03:13.12,Default,,0000,0000,0000,,[SOUND]\N>> This is a typical Victor handle.
Dialogue: 0,0:03:13.12,0:03:16.93,Default,,0000,0000,0000,,It's designed to deliver the gas\Nin a safe manner to the mixer.
Dialogue: 0,0:03:16.93,0:03:20.13,Default,,0000,0000,0000,,One of the big misconceptions in our\Nindustry is that the mixer is in
Dialogue: 0,0:03:20.13,0:03:21.86,Default,,0000,0000,0000,,the handle, and that's not true.
Dialogue: 0,0:03:21.86,0:03:25.29,Default,,0000,0000,0000,,Each individual component\Nhas its own mixer.
Dialogue: 0,0:03:25.29,0:03:28.55,Default,,0000,0000,0000,,Today, we're gonna talk about heating and\Ncutting,
Dialogue: 0,0:03:28.55,0:03:30.68,Default,,0000,0000,0000,,the most popular uses of the torch.
Dialogue: 0,0:03:30.68,0:03:32.77,Default,,0000,0000,0000,,>> And this is a heating attachment.
Dialogue: 0,0:03:32.77,0:03:36.96,Default,,0000,0000,0000,,A heating attachment can be used for\Nheat treating, priming,
Dialogue: 0,0:03:36.96,0:03:40.44,Default,,0000,0000,0000,,descaling, straightening,\Nmany other options.
Dialogue: 0,0:03:40.44,0:03:43.02,Default,,0000,0000,0000,,Before you use this heating attachment,
Dialogue: 0,0:03:43.02,0:03:47.74,Default,,0000,0000,0000,,you need to be sure to check the cone\Nend of your attachment has two O-rings.
Dialogue: 0,0:03:47.74,0:03:51.62,Default,,0000,0000,0000,,And on those O-rings, you have to make\Nsure they're neither missing nor damaged.
Dialogue: 0,0:03:51.62,0:03:55.45,Default,,0000,0000,0000,,That could lead to a leak that\Nmight lead to an accident.
Dialogue: 0,0:03:55.45,0:03:59.13,Default,,0000,0000,0000,,So be sure to repair them or\Nreplace them before using.
Dialogue: 0,0:03:59.13,0:04:01.97,Default,,0000,0000,0000,,>> And\Nhere's the typical cutting attachment.
Dialogue: 0,0:04:01.97,0:04:06.03,Default,,0000,0000,0000,,Do the same inspection on the cone end,\Nas Ken just advised.
Dialogue: 0,0:04:06.03,0:04:11.10,Default,,0000,0000,0000,,In addition, we also wanna make sure that\Nwe check the seating end for the tip, no
Dialogue: 0,0:04:11.10,0:04:16.64,Default,,0000,0000,0000,,dents or scratches in here, because this\Nwill eventually be a metal-to-metal seal.
Dialogue: 0,0:04:16.64,0:04:20.22,Default,,0000,0000,0000,,Before attaching the cutting\Nattachment to the torch,
Dialogue: 0,0:04:20.22,0:04:25.70,Default,,0000,0000,0000,,we wanna inspect the exceeding area of the\Ntorch handle and also the thread assembly.
Dialogue: 0,0:04:25.70,0:04:30.50,Default,,0000,0000,0000,,Then you wanna attach them,\Nhand-tighten only.
Dialogue: 0,0:04:30.50,0:04:34.41,Default,,0000,0000,0000,,At this point, if we use a wrench on it,\Nyou're gonna damage the O-rings.
Dialogue: 0,0:04:34.41,0:04:37.58,Default,,0000,0000,0000,,So we're gonna hand-tighten this on there,\Nall right?
Dialogue: 0,0:04:37.58,0:04:41.25,Default,,0000,0000,0000,,After you get that on,\None of the things we wanna do,
Dialogue: 0,0:04:41.25,0:04:46.51,Default,,0000,0000,0000,,we're now gonna take and open this\Npreheat valve all the way on the handle.
Dialogue: 0,0:04:46.51,0:04:50.36,Default,,0000,0000,0000,,If we don't open it all the way, you'll\Nget a restriction in your cutting oxygen.
Dialogue: 0,0:04:50.36,0:04:55.51,Default,,0000,0000,0000,,This will now be your preheat\Nadjustment for your oxygen.
Dialogue: 0,0:04:55.51,0:04:57.11,Default,,0000,0000,0000,,Now, we'll take a look at the tip.
Dialogue: 0,0:04:57.11,0:05:00.83,Default,,0000,0000,0000,,You wanna make sure you can inspect the\Ntip on the end, make sure preheat holes
Dialogue: 0,0:05:00.83,0:05:04.05,Default,,0000,0000,0000,,are free of debris, and\Nthe cutting hole itself is free of debris.
Dialogue: 0,0:05:04.05,0:05:06.44,Default,,0000,0000,0000,,You also wanna check the seating end.
Dialogue: 0,0:05:06.44,0:05:08.96,Default,,0000,0000,0000,,This is going to be a metal-to-metal seal,\Nso
Dialogue: 0,0:05:08.96,0:05:12.38,Default,,0000,0000,0000,,we gotta make sure there's no scratches or\Ndents in the system.
Dialogue: 0,0:05:12.38,0:05:15.54,Default,,0000,0000,0000,,Now, unlike the cutting\Nattachment to the handle,
Dialogue: 0,0:05:15.54,0:05:18.26,Default,,0000,0000,0000,,we'll now tighten this on with a wrench,\Nand
Dialogue: 0,0:05:18.26,0:05:22.59,Default,,0000,0000,0000,,you need to tighten it securely\Nbecause of the metal-to-metal seal.
Dialogue: 0,0:05:22.59,0:05:26.06,Default,,0000,0000,0000,,We'll then take a look at\Nthe cutting lever itself,
Dialogue: 0,0:05:26.06,0:05:31.20,Default,,0000,0000,0000,,make sure it moves freely, there's no\Nresistance, and we're ready to go.
Dialogue: 0,0:05:31.20,0:05:35.38,Default,,0000,0000,0000,,[SOUND]\N>> Your torch inspection checklist should
Dialogue: 0,0:05:35.38,0:05:40.62,Default,,0000,0000,0000,,include the following, inspect valves,\Nfittings, and seating areas for damage.
Dialogue: 0,0:05:40.62,0:05:44.62,Default,,0000,0000,0000,,Ensure both O-rings are intact and\Nin place.
Dialogue: 0,0:05:44.62,0:05:48.10,Default,,0000,0000,0000,,Ensure the torch is free from oil and\Ngrease.
Dialogue: 0,0:05:48.10,0:05:51.19,Default,,0000,0000,0000,,Make sure the tips are free from slag or\Nobstruction.
Dialogue: 0,0:05:51.19,0:05:55.50,Default,,0000,0000,0000,,[SOUND]\N>> Manufacturers such as Victor provide
Dialogue: 0,0:05:55.50,0:05:59.70,Default,,0000,0000,0000,,tip charts, and they help you to\Ndetermine the proper flow settings.
Dialogue: 0,0:05:59.70,0:06:02.57,Default,,0000,0000,0000,,Note that alternate fuels\Nuse different tips,
Dialogue: 0,0:06:02.57,0:06:05.53,Default,,0000,0000,0000,,and they require different\Npressure settings.
Dialogue: 0,0:06:05.53,0:06:08.96,Default,,0000,0000,0000,,>> The thickness of your plate would\Ndetermine what tip you use, and
Dialogue: 0,0:06:08.96,0:06:11.91,Default,,0000,0000,0000,,in turn, the tip will determine\Nwhat pressures I need.
Dialogue: 0,0:06:11.91,0:06:16.15,Default,,0000,0000,0000,,Take, for example, this is a number\None acetylene cutting tip, and
Dialogue: 0,0:06:16.15,0:06:20.78,Default,,0000,0000,0000,,I'll set my pressures at 25 PSA on\Nthe oxygen and about 5 on the fuel gas.
Dialogue: 0,0:06:20.78,0:06:24.75,Default,,0000,0000,0000,,If I would change thickness and, say, go\Nto an inch plate, I'd also have to change
Dialogue: 0,0:06:24.75,0:06:28.42,Default,,0000,0000,0000,,the tip to a number two and my pressures\Nwould be different at the regulator.
Dialogue: 0,0:06:28.42,0:06:31.55,Default,,0000,0000,0000,,So I'd refer to the tip charts\Nthat Ken had mentioned earlier.
Dialogue: 0,0:06:31.55,0:06:35.26,Default,,0000,0000,0000,,[SOUND]\N>> If you don't have tip charts,
Dialogue: 0,0:06:35.26,0:06:38.76,Default,,0000,0000,0000,,ask your equipment supplier to\Nhelp with recommended settings.
Dialogue: 0,0:06:38.76,0:06:42.57,Default,,0000,0000,0000,,Also remember the one-seventh rule for\Nusing acetylene.
Dialogue: 0,0:06:42.57,0:06:47.40,Default,,0000,0000,0000,,Make sure you have adequate capacity\Nfrom the acetylene cylinder to support
Dialogue: 0,0:06:47.40,0:06:50.81,Default,,0000,0000,0000,,the acetylene consumption\Nof the tip you're using.
Dialogue: 0,0:06:50.81,0:06:53.59,Default,,0000,0000,0000,,After connecting the attachments and tips,
Dialogue: 0,0:06:53.59,0:06:56.46,Default,,0000,0000,0000,,you need to check the entire system for\Nleaks.
Dialogue: 0,0:06:56.46,0:06:59.99,Default,,0000,0000,0000,,The steps to perform a leak\Ntest are as follows.
Dialogue: 0,0:06:59.99,0:07:04.76,Default,,0000,0000,0000,,First, ensure that the adjusting\Nmechanism is completely backed out.
Dialogue: 0,0:07:04.76,0:07:09.47,Default,,0000,0000,0000,,Open the gas slowly until the high\Npressure gauge reading stabilizes,
Dialogue: 0,0:07:09.47,0:07:11.75,Default,,0000,0000,0000,,then shut off the cylinder valve.
Dialogue: 0,0:07:11.75,0:07:14.51,Default,,0000,0000,0000,,Monitor the gauge for any pressure drop,
Dialogue: 0,0:07:14.51,0:07:19.01,Default,,0000,0000,0000,,which would indicate a leak of\Nthe high pressure side of the system.
Dialogue: 0,0:07:19.01,0:07:22.78,Default,,0000,0000,0000,,If no leak is evident,\Nopen the cylinder valve and
Dialogue: 0,0:07:22.78,0:07:26.55,Default,,0000,0000,0000,,adjust the oxygen regulator\Nto deliver 20 PSI.
Dialogue: 0,0:07:26.55,0:07:31.24,Default,,0000,0000,0000,,Repeat the process with the fuel\Ngas valve and regulator, but
Dialogue: 0,0:07:31.24,0:07:36.21,Default,,0000,0000,0000,,be sure to adjust the fuel gas\Nregulator to deliver only 10 PSI.
Dialogue: 0,0:07:36.21,0:07:40.93,Default,,0000,0000,0000,,Close both the oxygen and\Nfuel cylinder valves.
Dialogue: 0,0:07:40.93,0:07:46.13,Default,,0000,0000,0000,,Turn the adjusting screw or\Nknob counter clockwise one-half turn.
Dialogue: 0,0:07:46.13,0:07:50.00,Default,,0000,0000,0000,,Observe the gages on both regulators for\Na few minutes.
Dialogue: 0,0:07:50.00,0:07:54.47,Default,,0000,0000,0000,,If the gauge readings do not change,\Nthen the system is leak tight.
Dialogue: 0,0:07:54.47,0:07:56.54,Default,,0000,0000,0000,,Open the cylinder valves again.
Dialogue: 0,0:07:56.54,0:07:59.88,Default,,0000,0000,0000,,Any movement of the needles\Nindicates a possible leak.
Dialogue: 0,0:07:59.88,0:08:02.75,Default,,0000,0000,0000,,If you observe a leak, stop.
Dialogue: 0,0:08:02.75,0:08:05.07,Default,,0000,0000,0000,,Do not use leaking equipment.
Dialogue: 0,0:08:05.07,0:08:06.86,Default,,0000,0000,0000,,Check all the connections.
Dialogue: 0,0:08:06.86,0:08:08.56,Default,,0000,0000,0000,,If you can't find the leak,
Dialogue: 0,0:08:08.56,0:08:12.04,Default,,0000,0000,0000,,have the equipment inspected\Nby a qualified technician.
Dialogue: 0,0:08:12.04,0:08:17.08,Default,,0000,0000,0000,,Just like we purged a cylinder valve and\Nhoses earlier, we need to purge the torch.
Dialogue: 0,0:08:17.08,0:08:22.62,Default,,0000,0000,0000,,In this case, it's to eliminate the\Npossibility of gases mixing prematurely,
Dialogue: 0,0:08:22.62,0:08:25.48,Default,,0000,0000,0000,,which could lead to a flashback or worse.
Dialogue: 0,0:08:25.48,0:08:29.30,Default,,0000,0000,0000,,>> To purge the torch,\Nthe first thing you wanna do is
Dialogue: 0,0:08:29.30,0:08:33.40,Default,,0000,0000,0000,,open the oxygen valve on\Nthe torch handle all the way.
Dialogue: 0,0:08:33.40,0:08:39.31,Default,,0000,0000,0000,,And with a cutting attachment,\Nalso open the preheat oxygen valve and
Dialogue: 0,0:08:39.31,0:08:43.83,Default,,0000,0000,0000,,depress the cutting lever for\Nthree to five seconds.
Dialogue: 0,0:08:43.83,0:08:48.54,Default,,0000,0000,0000,,We'll shut that off and we'll repeat\Nthe process for the fuel side.
Dialogue: 0,0:08:48.54,0:08:55.18,Default,,0000,0000,0000,,We're gonna open the fuel side for three\Nto five seconds and then shut it off.
Dialogue: 0,0:08:55.18,0:08:59.28,Default,,0000,0000,0000,,>> And Ken, this is a good time to recheck\Nyour regulators to make sure you maintain
Dialogue: 0,0:08:59.28,0:09:00.34,Default,,0000,0000,0000,,the same pressure.
Dialogue: 0,0:09:00.34,0:09:01.40,Default,,0000,0000,0000,,[SOUND]