At my apartments today there was a worker from the local gas company (the truck said “pipeline surveyor” or something to that extent) that appeared to be putting a hex on the gas pipes outside the apartment. He was waving this medium-length stick with some kind of tapered protrusion (it almost looked like a miniature witch’s broom) at the end over various gas pipes. Anyone know what he was doing?
Either locating lines or checking for leaks. Both use a wand-type instrument.
Flammable gas detector. Presumably, someone had reported smelling gas in the vicinity and he was there to confirm and locate the leak.
If the truck said “pipeline surveyor,” he was probably there locating pipes for what we call Blue stake.
Last summer I had my outside grill replaced. The old one, which had basically rusted out, was on a post with a gas feed from inside the house. The new one was one of those wheeled things, and the folks that installed it replaced the old feed with a modern one with a quick-conect/disconnect coupling. One of the last things they did was wave a wand-type thing over the connect/disconnect coupling, both when the grill was connected and when it wasn’t. They told me that they were checking to ensure that there were no gas leaks.
So how do these magic wands test for gas leaks? Is it technology similar to those portable gas detectors firefighters use (and if so, why wand-shaped?)?
Wow, the sales people for those gizmos must be good.
Gas companies put butyl mercaptan, one of the most instantly recognizable and foulest-smelling things I’ve ever run across into gas so that leaks will be instantly detectable to anyone with a nose, but someone decides, no, we need a little widget that can tell us if there’s gas? That’s salesmanship there.
Watch out, Eskimos!
It’s a lot harder to detect outside, when a breeze is blowing, especially if the leak is small. Those gizmos can detect very small amounts when properly calibrated.
Flammable gases are flammable because they combine readily with oxygen. Most of these sensors make use of this characteristic in a variety of ways; one such common type is the catalytic bead sensor which heats a catalyst-coated inert bead to a high enough temperature to facilitate oxidation (but not hot enough to trigger explosion in a gas-filled environment.)
Many noses aren’t quite sensitive enough to rapidly pinpoint the exact place from which gas is leaking.
Also if decides that there is no leak in the area and there is later an explosion, he’ll be a lot better off telling the investigators that the magic wand didn’t detect anything rather then saying that he didn’t smell anything. Also, I’m sure there’s a lot of times where one can SMELL the leak but still isn’t able to locate it. Especially around an apartment building that might have many many many meters/shutoffs/connections/etc it would take a lot of time to check each of those for a leak with soap, but if you can use the wand to narrow it down to one bank of meters that would speed things along.
As for the wand shape, I’m guessing that’s to get into tight spaces (ie behind stoves, around bushes, under a crawlspace, buried in insulation in the attic)
If you feel like poking around the web for Mine Safety Appliance “sniffer” you might come across the device seen by the OP. There are different styles, some having low oxygen sensing <19% for confined space monitoring.
The ones I’m familiar with work as Q.E.D. describes, and not by detecting the mercaptan, which is for your olfactory sensor.
At one time it was a requirement of interstate transmission pipelines to have the lines walked by someone equipped with the device. The “witches broom” shape helped detect at the requisite PPM while keeping a moderate pace.
Reminds me of one day I came home for lunch and smelled gas on a strong breeze. My husband was home and I asked him to call 911, and he refused as he did not think it was an emergency. Infuriated, I prodded for KellyM to go in and get the phone and call. The fire dept. and the gas company were there quite quick. The first one who arrived was waiving a wand and the second guy there looked around, motioned to the first guy to put the wand up and pointed to the gas station being built on the corner. They went there, and everyone left the construction site quickly. It seems that they had broken a fairly large gas line and gotten lucky that no sparks had ignited it. It took a bit to get the gas cut off, but there was no fire or explosion. No emergency indeed!
It’s actually Ethyl (Ethanethiol)or Methyl Mercaptan (Methanethiol) they use as Butyl Mercaptan (Butanethiol)has serious health effects to humans and animals. Years ago,during a gas company strike in Toronto, a couple workers emptied a small bottle of the stuff while driving around the downtown core. Whole city block were evacuted, and police and fire were overwhelmed with calls.
Talk about you dirty filthy stinking pranks!
Get out of this thread, Sparky, there’s gas leaks in it!
They may be testing for other gases, present more-or-less naturally. Natural methane will not have the characteristic smell that we think of as ‘gas’ and sulphur dioxide, hydrogen sulphide and carbon monoxide either will not smell at all or can be missed at low [still lethal] concentrations.
My wife and I smelled gas in the basement last weekend and the guy they sent out had a little handheld device with a wand which he used to check all the joints in the gas pipes and the meter outside to determine if there was a leak.
The thing that was really weird about this episode was that both my wife and I smelled a very strong gas smell, but the detector didn’t register a single blip. I said to the gas man, “But you DO smell it, don’t you?” He said, “No, but that doesn’t mean anything.”
After a couple of hours the smell went away. I still have no idea what it was, but it apparently wasn’t gas.
Wow, ignorant and arrogant. Dangerous combination there, buddy.
He was actually putting a hex on your gas meter. Watch next months gas bill.
Code Compliance, as dictated by DOT regulations, requires natural gas utilities to survey all pipes in their distribution system for leaks every 3-5 years depending on material. The equipment used is a Flame Ionization (FI) detector
These documents provide a lot of info.
Publications - AGMSC Papers/G - General Topics/G-1.pdf