SY/T 6826-2011 in English

Scope

The purpose of this standard primarily includes the design, implementation, testing, and operation of CPM systems. These systems utilize algorithmic tools to detect hydraulic anomalies in pipeline operating parameters. The main use of these CPM systems is to identify leaks within their computational accuracy range, provide alerts for pipeline schedulers, and display relevant data to assist with decision-making. When abnormalities occur during operation or when a leak is detected, the pipeline scheduler should immediately begin an investigation, confirm the cause of the alert, and take appropriate countermeasures.

The purpose of this standard is to help pipeline schedulers determine issues related to CPM system selection, implementation, testing, and operation. This standard is used in conjunction with other API standards and applicable specifications.
1.2 Content
This standard includes terminology and definitions, referenced documents, data acquisition concepts, pipeline design and operational procedures related to CPM, field detection instruments for CPM systems, alarm reliability, pipeline scheduler response, event analysis, record-keeping, maintenance, system testing, training, considerations in setting alarm limits, as well as data trends and recommendations. It also outlines the relationship between pipeline schedulers and CPM systems.
1.3 Scope
The users of this standard should be knowledgeable about pipeline systems and may need to acquire relevant background knowledge from other standards.
This standard applies to single-phase liquid pipelines. Many principles can also apply to pipelines with intermittent or continuous submergence, which create uncertain pressure and flow conditions; users must consider their applicability.
This standard does not apply to leak detection in pipeline shutdown states (sometimes referred to as static conditions). For example, during a shutdown state, due to the absence of fluid passing through flow meters, CPM systems using volume balance methods cannot estimate volume loss.
Due to the unique characteristics of each pipeline system's design and operation, there is no specific CPM method or technology that applies to all pipelines. Additionally, different pipeline systems have varying characteristics making it difficult to quantify detection limits. Detection limits should be determined and verified on a system-by-system basis, even down to individual pipe segments.
When manual intervention or shutdown of affected segments is required, CPM aids in human judgment. Pipeline schedulers need to be familiar with the pipelines and all tools they handle to operate efficiently. In determining remote control valve statuses or guiding field personnel to open manual valves, CPM can enhance human judgment.
This standard complements other pipeline integrity monitoring methods but does not replace them. Both CPM systems and other leak detection technologies for product loss have their detection thresholds; leaks below these thresholds cannot be detected. Using this standard's information will not lower the detection threshold for leaks. For example, trained pipeline schedulers can effectively monitor certain scales of product loss by analyzing SCADA system operating data. Third-party reports, pipeline patrols, and employee site inspections are also valid methods to confirm pipeline integrity within their respective scopes.
It is important to note that this standard aligns with industry practices and commonly used technologies; however, it does not exclude the existence of other effective leak detection methods for product loss.
Appendix A provides an introduction to CPM thresholds and additional information to help understand actual pipeline leakage and product loss detection limits.
1.4 Pipeline Systems
Although this standard is written for land-based and marine trunkline pipeline systems, most of its content applies to other pipeline systems such as gathering pipelines, process pipeline systems, shipboard loading and unloading systems, and terminal tank farm operating control systems. CPM systems are typically used in steel pipe systems but can also be applied to pipes made from other materials like PVC, PE, fiberglass, and cement.
Many physical characteristics of pipeline systems include pipe diameter, length, wall thickness, internal roughness coefficient, piping combinations, network complexity, layout, pump station placement, and detection instruments (quality, accuracy, and positioning). Similar pipeline systems can also be classified based on operational factors such as flow rate, fluctuation magnitude and frequency of flow/pressure, blending, sequential batches, batch transfer schedules, product types, fluid properties of products (viscosity, density, speed of sound, volume modulus, vapor pressure), pressure, temperature, and heat transfer.