In gas lines they run the pressure at about 1100 psi so it acts like a storage tank, high pressure but low volume, not sure what pressure they run the fuel pipeline at, but they will more than likely be able to pig it while its in operation. They will just have a pig catcher at either end and at any pump stations on the way, that's how they do the main gas line up the country.
mm12345,
Sep 20, 8:21pm
Yeah - they pig the liquid fuel pipe for product separation - so it's normal. Not sure though if a pig with instruments to measure wall thickness etc could be run through the pipe at normal flow rates and still carry out measurements accurately. Back of envelope calculation is that normal flow rate is about 2m/s.
nice_lady,
Sep 20, 8:38pm
Not all planes us 'Avgas'. It actually had JetA1 'pouring out'. Very different fuel.
saxman99,
Sep 20, 9:05pm
I know what AvGas is and I know what JetA1 is. My source tells me the pipe was leaking AvGas at the time it was discovered, I believe this person until proven otherwise.
purplegoat,
Sep 20, 9:10pm
Its irrelevant what was leaking out of the pipe . The fact is the pipe is knaffed and until its fixed planes are affected indeed it could well have had multiple products leaking depending on how long it had been leaking for . its a fact the leak was detected by a pressure drop in the line but the officials are not saying how long it had been leaking it may have been a long a slow leak that slowly got worse until the pressure dropped enough to trigger the line pressure sensors . the only people who could answer that would be the people in the control room at the refinery who monitor the line and know what its operating paramaters are
martin11,
Sep 21, 4:10pm
All the reports say it was a jet fuel leak and the area smelt of kerosene in the dirt when they dug it up to find the damage to the pipe .
saxman99,
Sep 21, 4:21pm
That's nice. I believe what's happened is that the pressure drop was finally noticed during a load of JetA1 (which of course spilled) but by this time it had already been leaking a great deal of the previous load which was AvGas. So there's probably a bit of a mix of lovely volatile fuels in the ground, all of which will have to be remediated.
lookoutas,
Sep 22, 9:23am
You're like a dog with a bone mate. Before the Avgas there would have been 91, 95 petrol and any other fuel they so desired to send through. I'll bet they don't bother to separate any mixing between those three fuels. Same with Jet A1, Kero and Diesel.
dublo,
Sep 18, 9:45am
What a mess! 2015 the last time the pipeline was inspected and now all this trouble with the main supply route to the heaviest user (Auckland) all because some unknown dozo damaged it with his digger at some unknown time. Now, the pipeline apparently supplies diesel, jet A1 , 91 and 95 petrol. Are the various fuels pumped in separate pipes or all through a single one? If so, how do they separate one fuel type from the other? Is there a flushing system between deliveries of each type or can there be cross-contamination? I wouldn't want to be flying in a jet aircraft which has any petrol mixed with its fuel, or my cars suffer from low octane petrol or diesel mixed with their 95.
kevymtnz,
Sep 18, 10:00am
you need to get information correct before posting
saxman99,
Sep 18, 10:04am
Found this online, don't know if it applies to this one:
Batches of different refined products and grades are pumped back-to-back in the pipeline, usually without any devices separating them. Mechanical separators which are called pigs are seldom used in multi-product pipeline. Some mixing products occur at the interface of two adjacent batches. The interface material resulting from the pumping batches of different grades of the same product one after another, for example premium and regular gasoline, is typically mixed with the lower grade batch, thereby reducing the batch size of the higher quality product. Moreover, the interface between the two different products, like gasoline and a distillate produces a mixture, the so-called trans-mix. In this case, the trans-mix is cut out and sent to separate tanks, and reprocessed subsequently in full-scale refineries or special purpose-built facilities. The actual volume of the mixed material generated depends on some physical parameters such as the pipeline diameter, the flow regime, the traveled distance, the topography and types of adjacent products. At the oil refinery, each tank is usually dedicated to holding a single petroleum product to avoid purge and cleaning operations during the routine unloading and loading cycle. Moreover, different oil derivatives are delivered into distinct containers at nominated depots.
dublo,
Sep 18, 10:08am
Thanks Saxman, good to know how it is all done!
intrade,
Sep 18, 10:19am
Ah well as far as i know i told you about corrosion and cross contermination. one big problem i have is my workshop up north is quite close to marsden point by air. and the the only logical place you would drop a bomb in nz is on marsden point if nz starts attacking other countrys like north korea you can expect a nuke to hit right there.
morrisman1,
Sep 18, 10:22am
The PW127 on the machine I fly is approved for gasoline as an emergency alternate fuel so dont worry about a little bit of petrol getting into your jet plane, it won't know the difference.
nice_lady,
Sep 18, 10:29am
Hubby is an aircraft refueller. He says theres no problem. Petrol should it get mixed into the JetA1 would be noticed very quickly as for one it's a lower specific gravity and would seperate out pretty quick. The JetA1 he deals with has been through many tests and filters and inspections prior to it getting delivered to a plane.
A bit of Jet1 mixed into your Diesel wouldn't hurt but probably wouldn't be too good in petrol. However as stated the fuel companies are VERY VERY fussy about quality and tests and inspections.
noswalg,
Sep 18, 11:30am
Damn, there's a Gull servo down the road from me, do you think they'll drop one there too? Maybe I should prep!
serf407,
Sep 18, 12:26pm
If the US toasts the Nokos, the missiles would have likely been loaded in one of these sheds. https://youtu.be/IE6Qx9nVuGc
sr2,
Sep 18, 12:31pm
I've got a few cans of lawnmower gas in my garden shed, looks like I'll be digging a shelter in the backyard next weekend!
apollo11,
Sep 18, 12:38pm
No one is going to waste a bomb on the Wairarapa. Yay!
philltauranga,
Sep 18, 12:47pm
You will get the fallout from the one they use on Ohakea to stop all our skyhawk fighter jets. ooohhhh hang on.
nice_lady,
Sep 18, 1:02pm
Don't bet on that. The Govt in it's infinite wisdom is looking seriously at hosting a squadron of F18 Jets belonging to Singapore. That'll make the lower North Island a target quite possibly.
the-lada-dude,
Sep 18, 1:04pm
Trumps pushing China into a corner, she has to tidy this mess up, but I don't think they really have the balls to do it ? . not only that, but the Chinese and Koreans hate the Japs big time . Why ? well the Japs fair fu. ed the Chinese and Koreans with their expansionistic ideas that started off in Manchuria from about 1935 , then on to parts of the Pacific which culminated with the beginning of the end with the sly attack on Henderson airfield and Pearl harbour docks
bill-robinson,
Sep 18, 1:20pm
if i was you i would be digging a bloody deep hole, climbing in and pulling the dirt in behind me if you think anyone is going to bomb nz
richardmayes,
Sep 18, 1:50pm
Extracting oil, refining it, shipping it and selling it is big boys' stuff with a lot of money invested, I am sure there is a method to whatever they're doing!
I have no idea what the length is, of the zone of mixed fluids in the pipe between a delivery of one type of fuel and the next.
But ***IF*** the zone of mixing was say 100 metres long, simplistically the volume of that would be pi x (0.273/2)^2 x 100 = 5.85 cubic metres =5850 litres of mixed rubbish fuel. Which would be about $12,000 worth if it was meant to be 91 octane petrol. Saxman - I wonder if they even bother recovering and re-processing it? Any time I see footage of overseas oil pipelines / disasters, it's usually a pipe so big that a 5-year-old could walk upright inside it, and I could imagine a correspondingly bigger and more valuable volume of the trans-mix existing between loads in one of those pipes. ?
Since the public registrations are closed, you must have an invite from a current member to be able to register and post in this thread.
Have an account? Login here.