SUBSEA PIPELINE SERVICES
(HOT TAP & TIE-IN, INTELLIGENT PIGGING)
A. Hot Tap
A Hot Tap is define as using a drilling machine to cut hole into an in- service, underpressure piping system. This is done without service interruption or product leakage. Typical applications of a Hot Tap include making a branch connection, initiating a bypass and allowing performance of a Line Stop. Components required to perform a Hot Tap normally inculde a fitting designed to contain system pressure, a valve used to control new connection and a drilling or tapping machine.
Virtually every Hot Tapping job is different, and require Hot Tap Procedure before starting the job. Every procedure may need revision to Unique job specific problems or situations that may arise concerning the safety of personnel and facilities. Most Hot Tapping applies to piping and equipment fabricated from Ferritic and austenitic steel. Other materials, such as aluminum, copper, plastic, and cast iron may be unsuitable for Hot Tapping or welding or may require Special Procedure.
Tie-in is activities connecting new pipelines with pipelines old (existing). To make the process of tie-ins, existing piping can be in three condition. The condition is:
1. The existing pipe in a shutdown condition, in the sense that all processes through the entire pipeline network is in a state of not operating.
2. Pipe existing in a state of partial shutdown, in the sense that only the pipelines associated with the tie-in activity is disabled.
3. The existing pipe in an active state. This is commonly called hot-tap.
Types of tie-in is:
1. Flange connection, namely the process of tie-in with the wear flange that has previously been installed on existing pipelines, so it does not require any modifications to the pipeline.
2. Weld connection, namely the process of tie-in with weld new pipe to old pipe. This is because there is no flange on the old pipe.
C. Intelligent Pigging
In the context of the pipeline, pigging is the term used when a person uses a PIG (Pipeline Inspection Gauges) to perform various maintenance processes in the pipeline. The main purpose of the pipeline pigging is for cleaning and inspection. For the commissioning phase, pigging is required to:
1. Prove that the pipeline is perforated in accordance with
the design specifications and the pipeline development
2. Clean the pipeline from unwanted material which is the
remainder of the construction phase.
For the operating phase, pigging is required to:
1. Reduce / eliminate deposition / accumulation that may affect the production process (press drop, roughness, liquid slug, etc.).
2. Check for corrosion on the pipe.
3. As one of the methods of inspection to determine the quality of the pipe.
Pigging process is done by closing the pipe with PIG then put pressure usually uses water. PIG is pressed will move from the launcher (the initial position of the pipe) until it reaches the receiver area (end of the pipe). Pressure speed should be set up in such a way to prevent damage to the PIG. After PIG launched from Launcher to the Receiver, then the functions will be directly visible, ranging from cleaning to pipe inspection.
PT Aquamarine Divindo Inspection is having mutual exclusive cooperate with T.D. Williamson to perform above services.
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