Free Pressure Equipment Directive Guide

Posted on August 7, 2009


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Over the last couple of years I’ve worked on a number of projects that have involved the European Union Pressure Equipment Directive (or PED as it’s sometime known).  The Directive is legislation which aims to ensure that pressure equipment used within the EU is safe.  For the process industries, this most often means vessels and piping.

A key part of complying with the PED is to ensure that equipment has been classified correctly.  Basically this classification categorises equipment according to the degree of hazard should the equipment fail.  Equipment in the most hazardous applications, for instance large vessels containing toxic or flammable gases at high pressure, is required to have extensive quality assurance procedures throughout the design, manufacture and testing stages.  Equipment in low hazard applications, such as a small storage vessel for water at low pressure, has less onerous quality assurance requirements.

In the projects I’ve been involved with, equipment classification has been the responsibilty of the process engineers although the information is required by the other disciplines, especially piping and control/instrumentation engineers.  Higher classification requirements also tend to affect equipment cost and delivery, so project managers also have a keen interest!

Given that the PED is a legal requirement, along with potential cost and delivery implications, it is essential that equipment classification is carried out thoroughly and accurately.  To help you classify equipment correctly, I have written a free guide to the Pressure Equipment Directive which is available to download to all Blackmonk email subscribers.

To get your free copy just enter your name and email details into the boxes above or on the right hand side of this page.

I hope you find the guide useful and would appreciate any comments you might have.



10 Responses to “Free Pressure Equipment Directive Guide”

  1. Robert Kada
    Aug 15, 2009

    Since the PED covers pressures greater than 0.5 bar, how to clasificate piping and vessel which contain Group 1 fluid, under vacuum ?
    Thanks a lot.

  2. blackmonk
    Aug 17, 2009

    Hi Robert,

    Equipment with maximum allowable working pressures of less than 0.5 barg are exempt from the Pressure Equipment Directive. They should be designed, built and tested to appropriate standards but are not covered by the PED.

    Hope this helps.


  3. Brian
    Sep 01, 2009

    Your reply to the question on the vessel under vacuum seems to be the opposite of statement under guideline 1/13 from Enterprise and Industry Guidelines, see attached link;

    • blackmonk
      Sep 02, 2009

      Hi Brian,

      Thanks for the comment. Guideline 1/13 refers to vacuum insulation fitted to pressure vessels rather than vacuum vessels per se. Vessels designed for pressures less than 0.5 barg are not classed as pressure vessels within the Pressure Equipment Directive and therefore do not have a PED category.

      Vacuum insulation casings fitted to pressure vessels are considered to be part of the pressure equipment and are therefore subject to the Directive.

      Best regards,


  4. Jeff Ackel
    Sep 03, 2009

    How does PED address fins attached via an automated ERW process? These are fused and not welded, and don’t have any impact on the integrity of the vessel. We are a US company without prior PED experience, and cannot find any specific reference to fin attachments in our initial review of PED.

    Any assistance would be much appreciated!

    • blackmonk
      Sep 04, 2009

      Hi Jeff,

      I think in general the vessel including the fins would be considered a pressure vessel according the PED. The PED defines a vessel as “a housing designed and built to contain fluids under pressure including its direct attachments up to the coupling point connecting it to other equipment. A vessel may be composed of more than one chamber.” On this basis I would consider the fins a direct attachment.

      Some guidance regarding definitions can be found here:

      And some guidance for heat exchangers is given here:

      Hope this helps,


      • Jeff Ackel
        Sep 04, 2009


        Thank you for your promt reponse. We asked the question because ASME here in the US grants an exception for externally welded fins since they do not affect the ability of the vessel to retain pressure. In effect it treats them like the attachement of a name plate, which is considered differently from things like stiffening rings and lifting lugs. We assumed PED would grant a similar exception. Do you know how PED treats external attachments like name plates?



  5. Hi Simon

    We are frontline and single manufacturer and supplier of cold drawn seamless steel pipe and tubes of dia. 20- 273 mm , meeting the requirement not only in the country but exported our tubular products to abroad.
    We are ISO 9001, ISO 14001, ISO 18001, API 5L, API 5CT and IIP certified compny.
    We are hydrostatically testesting accordance with applicable international standards or customer requirement to each tubular product prior to deliver to customer. We are issuing compliance or Mill Test Certificate against the each order.
    My question is, that how the PED is applicable in our case, when no pressure exist during the transportation in the country or abroad.
    Pressure exist in the end user application for vacuum, pressure or liquid transportation in their facilities and works.

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