What is a pipeline?

It was recently pointed out to me that AS 2885 does not have a definition of “pipeline”.  No-one has ever raised that before, perhaps because most of us think we know a pipeline when we see one regardless of any formal definition.  But it made me think about how one should define “pipeline”.  How about this:

  • Cylindrical conduit that conveys fluid under pressure
    • Necessary to start with the very basics
    • Excludes open channels and non-circular ducts
    • “Fluid” may include gas, liquid, multiphase, supercritical or slurry
  • Traverses areas outside the exclusive control of the owner/operator
    • Excludes process piping and in-plant transfer lines
    • Usually but not necessarily of considerable length
  • Has few inlet and/or delivery points
    • Excludes complex distribution networks
    • Production gathering systems may be moderately complex networks, but each element of such a network is usually considered to be a pipeline in its own right
  • May include facilities for pressurising, controlling and measuring flow
    • Excludes processing and storage facilities

For something that I usually think of being as simple as a long round piece of steel with a hole down the middle that’s surprisingly complex isn’t it?  But complexity behind superficial simplicity is pretty typical of pipelines.

This is not meant to be an AS 2885 definition because it covers a lot of pipelines that are outside the scope that standard (eg. water and slurry lines).  Rather it’s just a thought for discussion.

Is it an adequate definition?  Are there legitimate pipelines that it would exclude?  Or non-pipelines that are not excluded?

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12 Responses to What is a pipeline?

  1. Mike Dinon says:

    Peter, The very best pipelines don’t have a hole down the middle. It’s the hole that causes all the problems. Once you eliminate the hole down the middle, you eliminate all flow control and internal corrosion concerns.

    On a more serious note, you are on to something. I recently had to decide whether buried pipes outside a facility fence were more appropriately called a pipeline assembly or a pipeline. I came down to a pipeline for very similar reasons to those you list, but I was surprised to find the actual standard doesn’t make it as clear-cut as I would have liked and other persons could easily have mounted a counter-argument.

    • petertuft says:

      I think that’s a finer level of distinction than I was aiming at. Pipeline assemblies are still part of the pipeline, at least under AS 2885, in the sense that they do not need to be designed to some other code.

  2. Mark Coates says:

    The dictionary (or on-line dictionary/s) is a good place to start.

    Both ASME B31.8 and AS4041 include definitions for pipelines, pipe, piping systems, gathering systems, etc. In addition, codes such as AS2885.0, ASME B31.3, and ASME B31.1 include diagrammatic representation of boundaries between pipelines, pipeline assemblies, process piping, etc.

    Key points are that it is a fluid transportation system (can be pressurised or atmospheric) to differentiate from pressure and/or storage equipment which have measurable residence time, and that it travels over longer cross-country distances (ie not confined to inside a locally defined or fenced-off area).


    Mark C.

    • Ross Calvert says:

      I am not convinced there is a need for a definition as it may raise more issues than it solves. Some explanatory material about what the code is intended to cover is useful.

      I recall that when the first Pipelines Access Code was being drafted, there was an attempt to distinguish between transmission and distribution pipelines which was not resolved. When in doubt, my recommendation is to apply the “duck test” viz. if it quacks like a duck, swims like a duck, walks like a duck and looks like a duck, it can be reasonably concluded that it is a duck.
      Ross Calvert

  3. Philip Venton says:

    I’m probably a bit silly, but I have difficulty in identifying a problem.
    1) The name of the Standard is “Pipelines….”
    2) A pipeline is a commonly used term and there is no possibility of it being confused with another transportation system.
    3) AS 2885.0 includes a diagram that defines the scope of the Standard, including a definition of separation between an upstream or downstream process or equipment item.
    4) AS 2885.1 includes a diagram that defines the separation between the “station” and “pipeline” components of a pipeline system.
    5) It is possible that the diagrams in Part 0 and Part 1 could be improved.
    6) The Standard is already overly complex and lengthy.
    7) There are more important things that we should be concentrating our efforts on, including clearly separating the different requirements for a new pipeline constructed as a new project, separate from an operating organisation, and an existing pipeline that is being operated and maintained (and possibly expanded).
    Phil Venton

  4. Anonymous says:

    I think the accident at Veranus Island a few years ago revealed an oddity about the regulatory jurisdiction over a pipeline as it enters a facility at a beach crossing.

  5. petertuft says:

    Possibly a mistake for me to even mention AS 2885 in this post as I was not intending that this be viewed as a draft definition for use in the standard (although I did point out it was not meant to be an AS 2885 definition). I just thought it was an interesting exercise to try to define explicitly what characteristics are necessary to pass what Ross calls the “duck test”.

    One offline comment has already pointed out a shortcoming in my draft definition – there are a number of gas storage pipelines around that are unequivocally pipelines but whose role in actually conveying gas is questionable.

  6. Cameron Dinnis says:

    I sometimes use a cylindrical conduit to convey fluid under pressure onto the grass outside my property’s boundary. But I don’t think I use a pipeline to water the footpath. 😉

    Maybe that means there are also size/pressure/service requirements?
    Maybe a pipeline needs to be made up of a “line of pipes”; i.e. more than one of those fluid-conveying-cylindrical-conduits joined together?

    I don’t think you’ll be able to come up with a formal definition that doesn’t include things that should be excluded and doesn’t exclude things that should be included. So I think the Calvert Duck Test is a good approach. It has the added benefit of also working for “art”…

  7. petertuft says:

    Touché – perhaps it is indeed futile to attempt a definition and the Calvert Duck Test should remain the benchmark.

  8. Hi to all and only just picked this one up. In NZ our “Pipeline Regulations” embodied in the HS in E Act have defined a “pipeline” as below. As Peter T stated in the start of this Blog. simple yet complex but does define parameters that are deemed to constitute a ‘pipeline’

    (a) means—
    (i) any pipeline that was authorised under the Petroleum Act 1937; or
    (ii) any pipeline or proposed pipeline likely to be permanent and used or intended to be used for the conveyance of any mineral, petroleum, geothermal fluid, natural gas, or any other fluid that, at ambient conditions, has inherent properties that may create a significant hazard; and
    (b) includes any part of a pipeline or proposed pipeline, including—
    (i) any directly associated fitting, pig launcher, or receiver; and
    (ii) any pressure vessel and its associated appurtenances, including any compressor, filter, separator, coalescer, or pulsation bottle; and
    (iii) any natural gas cooler associated with any pipeline compressor, pump, or tank; and
    (iv) any appurtenance required for the conveyance of the product or material in the pipeline or for its safe operation; but

    (c) does not include—
    (i) any bulk storage installation; or
    (ii) any pipeline wholly within the boundary of the plant that the pipeline is servicing; or
    (iii) any pipeline between a bulk storage installation and another form of transport that is not an extension of a pipeline as defined in these regulations; or
    (iv) any pipeline with a pressure of 2000 kP gauge or less under the control of a gas distributor and used to distribute gas from the boundary of the gasworks or gate station or outlet flange supplying gas for distribution; or
    (v) any pipeline or part of a pipeline offshore that forms part of an offshore petroleum operation; or
    (vi) any pipeline 150 mm in diameter or less that is not associated with the production of electricity and that contains geothermal fluids; or
    (vii) any pipelines solely used for the purposes of conveying water

    pipeline operation means any work in connection with a pipeline, including its design, construction, operation, maintenance, and abandonment

    pipeline worker—
    (a) means any person employed or engaged in any capacity in or around a pipeline operation; and
    (b) includes any contractor or subcontractor engaged to carry out any work relating to the operation, and the employees of any such contractor or subcontractor

  9. petertuft says:


    But if you didn’t already know what a pipeline is that wouldn’t be much help to you …

    • Get what you are saying and yes; it could even be box section that is conveying material. The dictionary definition is closest but then again in the English language could also be something you smoke, a musical instrument etc. Best way may be to define it with pictures.

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