Spotted this gas tanker what looked
Like to be leaking at Clacket lane last week,question is why would it be leaking like this the driver seemed to be not very bothered by it and was playing with some valve it went on about 30 minutes he then casually drove off,is this gas explosive his UN num was 2YE 1972
Methane. I’ve mainly carried cryogenic gases so can only speculate that it was a pressure relief valve venting off. Obviously with cryogenics that wouldn’t be a particular issue. Methane venting however could present a whole world of problems. Are you sure that you read the hazard placard numbers correctly?
Edit to add; it certainly doesn’t look like methane venting off.
UN 1972 is flammable Methane .
The pressure in the tanker must have been lifting the safety valves for the driver to be venting like that to reduce the internal pressure
OR … the driver was wanting to de -pressurise the tanker before reaching a loading point to save 5 minutes on the loading point.
Releasing Methane into the atmosphere is forbidden by shipping companies . It is worse for the environment than Carbon dioxide.
Can you name the transport company ?
As Maoster says – UN 1977 is Nitrogen so venting that isn’t a problem. Were you correct with the UN Plate ?
the maoster:
Methane. I’ve mainly carried cryogenic gases so can only speculate that it was a pressure relief valve venting off. Obviously with cryogenics that wouldn’t be a particular issue. Methane venting however could present a whole world of problems. Are you sure that you read the hazard placard numbers correctly?Edit to add; it certainly doesn’t look like methane venting off.
Definitely 1972 the girl in the bp forecourt also came for a look and reported it as she googled the UN number,does this product not vent
Name and shame the company . It’s forbidden except when the pressure is too high in the tanker . The safety valves lift between 4 and 6 bar depending on the set up .
Certainly should not be venting in such a public area and certainly not for 30 minutes.
Rob077:
does this product not vent
It does indeed vent Rob. I’m certainly no expert but the colour of the gas doesn’t look like methane, more like CO2 or Nitrogen. I stand to be corrected however.
It’s a cryogenic gas and is colourless . A Methane gas tanker looks like a nitrogen tanker when venting. I transport UN 1972 in France.
I bow to your experience Owenmoney. I’ve only carried CO2 or NH3 in tanks.
Would nitrogen have the 2YE code ?
How would pressure increase in a tank requiring venting? Increase in temp?
I`m strictly an amateur in this of course.
What temperature was it at the time? If below 0C then that could partly explain what you were seeing.
OwenMoney:
It’s a cryogenic gas and is colourless . A Methane gas tanker looks like a nitrogen tanker when venting. I transport UN 1972 in France.
Would it catch fire then if this would get to an ignition source the liquid after me
Checking about it is very cold,is this normal then
Franglais:
Would nitrogen have the 2YE code ?
How would pressure increase in a tank requiring venting? Increase in temp?I`m strictly an amateur in this of course.
Nitrogen would certainly have the E part (evacuation) because you simply can’t breathe in nitrogen rich environment. The Y denotes flammable so nitrogen doesn’t fall into that category being an inert gas. Most gases(bearing in mind I only have slight experience) is loaded cold, varying from -1 to around-200 (-249 being absolute zero) so any temperature increase is going to cause expansion and therefore the need for pressure relief. However, in my experience the only time this has been an issue is in temperatures in excess of 25 degrees C, obviously not applicable in this case
the maoster:
Franglais:
Would nitrogen have the 2YE code ?
How would pressure increase in a tank requiring venting? Increase in temp?I`m strictly an amateur in this of course.
Nitrogen would certainly have the E part (evacuation) because you simply can’t breathe in nitrogen rich environment. The Y denotes flammable so nitrogen doesn’t fall into that category being an inert gas. Most gases(bearing in mind I only have slight experience) is loaded cold, varying from -1 to around-200 (-249 being absolute zero) so any temperature increase is going to cause expansion and therefore the need for pressure relief. However, in my experience the only time this has been an issue is in temperatures in excess of 25 degrees C, obviously not applicable in this case
Y doesn’t necessarily denote flammable. It’s simply that there is a danger of explosion or violent reaction. Some gases and liquids will do that just on contact with air, without any flame.
Ref the UN number, 1972 is liquid form I think, with 1971 being compressed. I don’t know enough about either of them as our tank work is non-ADR, but would a liquid state be venting vapour in such a way as the pics above suggest? 
This is the rear of my methane tanker . The two silver pipes lead from the safety valve system so if the pressure was to get over the designed pressure the safety valves would lift allowing the pressure to be reduced in a controlled, safe way.
I have only seen it happen when there was a problem with the internal insulation .
We don’t have the same 2YE code in Europe therefore my tanker has a 223 plate.
I would think the O/p saw a nitrogen tanker after a delivery where the pressure had been raised to do the delivery but the gas still in the tanker would cause the pressure to mount. Bearing in mind that we are actually carrying gas that has been refrigerated into it’s liquid state . Methane is - 160 degrees .
I would hope the person from the Bp garage transposed the number 2 from a 7 in the UN code.
OwenMoney:
0This is the rear of my methane tanker . The two silver pipes lead from the safety valve system so if the pressure was to get over the designed pressure the safety valves would lift allowing the pressure to be reduced in a controlled, safe way.
I have only seen it happen when there was a problem with the internal insulation .
We don’t have the same 2YE code in Europe therefore my tanker has a 223 plate.
I would think the O/p saw a nitrogen tanker after a delivery where the pressure had been raised to do the delivery but the gas still in the tanker would cause the pressure to mount. Bearing in mind that we are actually carrying gas that has been refrigerated into it’s liquid state . Methane is - 160 degrees .
I would hope the person from the Bp garage transposed the number 2 from a 7 in the UN code.
No I can assure it was 1972, the cctv clearly showed this needless to say whatever was going on it wasn’t safe and the driver from what I can gather from these comments seemed to venting the pressure manually from this tanker thanks for all your advise I understand a bit more now he clearly had no regards to his and other safety.
Name and shame
I have a mate who regularly blows off methane, has done for years…he doesn’t drive a tanker either btw. 
Mick Bracewell:
Ref the UN number, 1972 is liquid form I think, with 1971 being compressed. I don’t know enough about either of them as our tank work is non-ADR,
Constructive post. In this spirit my advice is EVERYONE RUN! ITS GONNA BLOW!
robroy:
I have a mate who regularly blows off methane, has done for years…he doesn’t drive a tanker either btw.
That’s forbidden, unless the safety valve comes into operation.
switchlogic:
Mick Bracewell:
Ref the UN number, 1972 is liquid form I think, with 1971 being compressed. I don’t know enough about either of them as our tank work is non-ADR,Constructive post. In this spirit my advice is EVERYONE RUN! ITS GONNA BLOW!
Well at least there’s no danger of anything blowing up in your house, seeing as you’re unable to figure out how to turn the gas on to make your tea. 