On-site instrument installation, commissioning time

Without the help of an expert to let me know, I’m not sure if it was posted in the wrong place.

I’ve been too busy these past few days and haven’t had time; I’ll find some time to reply – there’s quite a lot to address.

When it comes to instruments alone, the range is quite wide, as different types of instruments have different installation times. In general, those that affect the subsequent pipeline purging, such as orifice plates, flow meters, and control valves, need to be installed after the pipeline purging is completed; the rest can be installed wherever conditions permit.

1. Does one have to wait until the process pipelines are installed and the slag is blown away before installing instrument orifice plates, valves, and the like? After most of the equipment is installed in place, the process piping work begins. The flow meters, control valves, and isolation valves connected to the process pipes are delivered by the instrumentation installation team to the process installation team, who then install them along with the pipes. During this period, the Party A personnel (construction managers and operators) along with the supervisor should monitor all aspects of the installation process, such as whether the inside of the pipes is clean and whether the straight sections of the flow meters meet the required standards. Instrumentation personnel should get involved in advance by attending the review meetings for the instrumentation construction drawings, so as to understand the overall design concept and requirements for instrumentation throughout the project. During the construction process, they need to pay attention to issues such as the orientation of the pressure tapping points for flow meters, as well as the installation location, orientation, interface dimensions, and material suitability of primary components like those used for measuring temperature, pressure, and differential pressure. Any problems identified should be reported immediately to the Party A’ s instrumentation management staff or process construction management staff. This process is the key aspect of the entire project installation. Although there shouldn’t be many problems if construction is carried out according to the plans, issues can still arise. When the design team is small or there is insufficient communication between the parties, as well as poor coordination among specialists, more problems will occur. 2. The process pipelines need to undergo purging, pickling, etc. What should the instrumentation team pay attention to? After the process piping is installed, tests such as subsystem pressure testing are required in accordance with regulatory standards. At this stage, the construction party will carry out the preparatory work based on the pressure testing plan approved by the client and the supervisor; your production staff should review this plan in advance to determine how the control valves, shut-off valves, flow meters, and other process-related instrumentation are protected. Under normal circumstances, instrumentation devices are not involved in pressure testing, as pipeline pressure testing is also a type of destructive test; such tests have already been conducted on the instrumentation devices before they leave the factory, and they pass those tests ； All instrument equipment connected to pipeline flanges shall have splices fabricated by the construction party ； Once the pressure testing is complete, if the process requires the pipeline system to be pickled, it is up to Party A to decide whether the instrumentation equipment will be involved in this process; if not, the spools can remain in place ； If participating in such activities, special attention should be paid to the water drainage during hydrotesting, to check whether there are any unwanted substances in the water such as weld slag, wooden pieces, or electrode ends. If such items are present, there is a risk that the valves may be damaged; in such cases, it is possible to request that the relevant personnel take measures to remove them (though this can be difficult to do). Pipe acid cleaning is a task with special requirements. Under normal circumstances, purging and system airtightness testing are carried out after applying water pressure. If time permits, the resetting of flow meters and valves can be delayed until after the purging is completed; however, they should be reset gradually as the purging progresses – that is, several components are reset after each section of the pipe has been purified, rather than all of them being reset at once after the entire purging process is finished. Strictly speaking, the thermometer should not be used in the purging process, to prevent rapid air currents from breaking the temperature sensing element; if that’s not possible, simply remove the core of the thermometer and keep only the protective tube in use. At this stage, conflicts can easily arise regarding procedures between the instrument workshop, the construction units, and the construction management staff. In terms of the project timeline, speed is of utmost importance; it is likely that there will be demands to carry out pressure testing and purging with the instrument equipment in place. The workshop, on the other hand, wants to protect the instrument equipment from damage, and usually requests that it be reset afterward. Resolving such issues requires coordination within the company. This is also why it was required earlier that the client’s personnel get involved in advance to supervise the cleanliness of the pipeline construction – if everything is clean from the start, the instrumentation and equipment will not be damaged during pressure testing and purging. With this in mind, you can take an active role when coordinating with the management. It is particularly important to mention pickling. As instrumentation personnel, one must review the pickling plan and pay attention to whether there are any incompatibilities between the acid used for pickling and the materials involved in the instrumentation that will come into contact with this acid; the main concern is whether such acid will cause corrosion to the instrumentation materials ； Furthermore, based on experience, a large amount of dark liquid remains inside the pipes after pickling, similar to sludge. If control valves, flow meters, and other devices are to be subjected to pickling, it is necessary to prevent them from getting clogged or covered with debris, ensuring that these instruments and pressure guiding tubes are thoroughly cleaned during the flushing process. During the pickling process, towards the end of the cleaning phase for the main pipeline (pickling involves several steps, and the instrument pressure pipes need to be treated separately in each step), it is necessary to drain the acid used for pickling from each pressure pipe individually. The drained acid should be collected using containers such as buckets, and the results should be monitored ； During rinsing, the same procedure applies. 3. When can the instruments generally start to be put into use, that is, when is the first valve of the instrument’s pressure lead pipe opened to connect it with the process pipeline? After the airtightness test is completed, the phase of gradually starting up the instruments begins. Different process units have different timing for starting up their instruments; if the unit involves a water testing process, the process requirements dictate that the instruments be started up gradually during that testing period. If there is no water interconnection, it can be put into use gradually according to the timing required by the process. Of course, given the large number of instruments, it is sufficient to open the root valves (primary valves) in advance and leave the valves in front of the instruments closed. The practices of different units regarding the activation of instruments vary; in principle, it is necessary to meet the requirements for process commissioning, and as long as it does not cause damage to the instruments, starting earlier is not a problem. The calibration of analytical instruments should be carried out during or after the normal operation of the installation, in order to prevent unstable media from damaging the pre-treatment and analysis equipment. For now, due to differences in management approaches among various organizations, there may be variations in methods, so it’s necessary to analyze each specific situation individually. Let’s discuss the issues together.

Thank you! It’s still those with experience who explain things clearly.