Monthly Archives: October 2015

Are our relief streams ready…?

Proving relief streams and devices are an important aspect of our check-out so we must consider the implication and organisation of this vital activity.

As a minimum, we should divide the checkout of relief devices and streams basically into three elements, 1. Inspection and labelling of relief pipe work, 2. Installation and 3. Pre-use testing, let’s briefly look at each element…

  1. Inspection and labelling of relief pipe work The commissioning team should check all scopes of work and if required organise the checkout of relief streams inlet and discharge pipe work, or in more basic terms the inlet line to say a relief valve and the discharge line to ensure cleanliness and clear bore. The checkout can be organised via visual inspection, blowing through of air, or flushing of water, pigging or the utilisation of a smoke bomb. A procedure should be written to describe the checks to be undertaken. We must also ensure that all relief pipe work is correctly labelled as per the site instruction or policy.
  2. Installation As relief streams are of significant importance to the safety of the plant, it is important that relief devices are installed correctly, hence it is a common practice that a suitably trained and competent engineer or technician witness the installation of relief valves and bursting discs. The commissioning team should make themselves aware of such site procedures and plan to attend and document the installation checks as required.
  3. Pre-use testing As with installation checks, the commissioning team should make themselves aware of the protocols the relief devices will be subject to prior to use and document accordingly. A good example of this is bench testing by the owner of relief valves. If this protocol is being observed, then the commissioning team should clearly understand what is to be done and capture what needs to be checked off as the relief devices are installed, potentially with specific tags or whatever the site policy would be.

Relief streams are an important aspect of plant design and we as a commissioning group should accept that ensure our standards of checkout meet the requirements for these systems.

Safe and successful commissioning always…

Plant control during commissioning…

As we enter the pre-commissioning phase as loops get tested, motors bumped, cleaning occurs plus other key activities, it would be normal to control and conduct these activities within the confines of the control room, but what are your arrangements once the plant starts to be commissioned or even operated?

Pre-commissioning equates to lots of activity, not only in the field but in the control room also as much radio traffic co-ordinates loop checks and motor rotation checks. This can have a profound effect on those who will start to commission the plant and most important as we start up, so good consideration should be made on the impact to the start-up, the noise and chatter pre-commissioning crates. Consideration should be given to the setup of satellite control rooms, perhaps for the pre-commissioning or the commissioning and start-up, we may also want to consider different radio channels or communication networks so pre-commissioning is separate and hence radio communication less confusing for those involved with the commissioning and start-up activities.

So much implication here, if satellite systems are to be incorporated, this thought process needs to be early so we can account for potential additional commissioning control hardware in the commissioning budget.

Safe and successful commissioning always…

Who will punch list..?

As construction comes to a close on their work scope and that magical threshold is reached (roughly 75% of the build), the construction team will hopefully start to consider a commissioning system turnover, hence we should as a commissioning team be ready to punch list, or snag the work in readiness for acceptance.

Of course as a basic document the punch list should be compiled against the P&ID’s for the system, but other supplementary documents can also be utilised such as isometric drawings. The big question to ask and get a plan together for however, is who and when do we punch list?

Most EPC companies will want, as there work finishes, to check their work internally, this may include installation subcontractors where a principle contractor is in place. We as a commissioning group as acceptor must be offered a chance to punch list, but what about the design team, are they in the loop to check the design intent has been met, do they need to? What about Operations and Maintenance personnel, they will have an interest as they will probably own the asset going forward and hence must also have the opportunity to contribute to the punch list process.

So in very simple terms, a fairly straight forward activity such as punch listing can become cumbersome if we do not plan for attendance of the right groups at the right time, teams being left out from the opportunity to punch can develop lists which can become frustrating and difficult to manage at a time when the focus needs to be on execution, so good punch list planning is an absolute must.

Safe and successful commissioning always…