In the previous article, we discussed the fourth phase: “Engineering & Procurement” and the steps that are usually performed in this phase. This article will discuss the third phase “Construction & Turnover”.
PHASE III: Construction and Turnover
At some point within and in parallel with the detailed engineering stage, the fieldwork and construction activities being, initially involving site preparation and civil work. However, it is important to know that construction actually begins with a highly critical planning effort starting at the earliest phase of the project development and integration. Construction should be considered both initially and coincidentally, and factored into all project phases, until successful plant operation and project close-out.
The concept of “constructability” is the optimum use of a construction knowledge and experience in planning, engineering, and procurement and field actions to achieve overall project objectives. Smooth and successful construction can take place only if the executions of the engineering phase and material procurement to the site have been executed on schedule.
In the construction phase, all upstream engineering efforts and downstream operational requirements interact. It includes major works such as piling and underground piping works and erection. The major part of the construction starts with the erection of major towers, furnaces, piperack structures, piping installations, shelters for major compressors and turbines, and instrumentation.
Turnover is a one-time event during the industrial plant project life which includes the user taking responsibility for maintaining and operating the system from the contractor. As with most building projects, users are anxious to start moving in and taking beneficial use of the facility before the plant systems are complete and fully functional. However, it is not recommend that the user take on operational responsibility until all of the systems have been accepted as functionally complete. This should of course include thorough systems training of the user's operations staff. Hence the turnover part of a system/subsystem is a crucial link.
System/Subsystem Turnover Requirements
Turnover of plant systems/subsystems are a major part of a mechanical completion. The contractor has to prepare all relevant documents dedicated to the turnover.
These documents, which usually include the general requirements and documentation of plant systems and subsystems, are often called the system turnover completion books. These books should include the following, as a minimum:
- system definition and description, - system turnover notice and guidelines, - final punch list/exception list, - preservation history report, - recommended spare part list, and - lubrication/grease schedule.
Other important documents (as required) that may also be verified and given the appropriate attention include P&ID list and drawings (highlighted or color coded), plant material and utility balances, catalyst and chemical summaries, equipment data sheets, relief valve and flare load summaries, operating manuals, control narratives, cause & effect matrices and shutdown logics, corrosion management guides, plot plan, electrical one-line diagrams, etc.
Certain prerequisite activities are necessary for turnover of each system and commissioning of the industrial plant. These activities are necessary to prepare the plant or parts thereof for commissioning or initial operations at the completion of each system. Such activities are also termed “pre-commissioning activities.”
Prior to turnover, the contractor usually must do cleaning and tightness-assurance activities for each system which include hydro test, water flushing, air blowing by temporary compressor or cracked gas compressor, steam blowing, chemical cleaning, sand blasting and mechanical cleaning, etc. It may be noted that these activities require some available utilities such as electrical power, steam, fire water, air (plant and instrument), water (service, drinking), nitrogen, etc.
In the next part of this series, we will discuss the fourth phase of the industrial project “PHASE IV: Commissioning and Startup”.