Monthly Archives: September 2015

Vendor P&ID’s…

It is common as we design and develop our plants that Vendor P&ID’s can be utilised in the complete set of P&ID’s for a plant, I wish to consider this implication in my brief today.

Usually P&ID’s are drafted by the EPC company designing the plant, however it is common for any vendor packages purchased, refrigeration systems, air compressors etc. to utilise the Vendor P&ID’s in lieu of back-drafted EPC generated versions. While this is the most economical approach we as a commissioning group must therefore take care when addressing certain aspects of our work.

  1. Can we understand the P&ID’s? Vendors will or may not use the same diagrammatic representation as your company or EPC drawings, so ensure you fully understand the symbols, methodology and meaning to a Vendor P&ID’s.
  2. Have the Vendor P&ID’s been systemised and all items included in their documents and drawings included on our check sheets and incorporated in our procedures?
  3. Have we got a master set of Vendor P&ID’s incorporated with our EPC versions?
  4. Can we interpret the drawings such that we are sure all safety and trip related action is covered on the Vendor P&ID’s and therefore most importantly captured either in the Vendors Site Acceptance Test and setting to work procedures, (if the Vendor is actually commissioning the equipment) our in our commissioning procedures?

Utilising third party documents can cause loop holes in our system and we must be on guard to ensure we are flawless in our preparation and execution.

Safe and successful commissioning always…


Identification of commissioning systems is the basis of our work, everything we do is based on them from organisation of our documents through to giving focus on construction to complete work areas or systems?

Is it plain however what a system means? As I like to say misunderstanding leads to confrontation as the unknown will always be challenged, so my guidance would be to explain what a system is.

For me a system is a discreet section of the plant, which when handed over to commissioning heralds actual work for the commissioning team starting, we can introduce energy, leak test, dry and or water commission through chemical introduction and start-up. Defining systems can cause irritation and confusion to installation companies who wish to work by areas or bigger sections of plant, so a full implication of this needs to be considered in any schedule to develop efficient and effective plans, for sure you need agreement across the board.

Commissioning systems are just such a fundamental organisational feature of commissioning there can be no confusion as to what they mean, invest the time to gain a consensus on the systems concept.

Safe and successful commissioning always…