Austria AT   
Impulse Line Blocking Diagnosis

Impulse Line Blocking Diagnosis

Introduction

Impulse Line Blocking Diagnosis in DP Transmitters

Figure1. Connected to impulse lines
Figure 1 Connected to
impulse lines

Differential pressure (DP) flowmeters composed of an orifice plate, a DP transmitter, and other components are widely used in many applications because they are reliable and require no wet calibration. The simple design of orifice plates and modern DP transmitters make them extremely reliable. However, the impulse lines which transmit process pressure to the DP transmitter are vulnerable to blockages caused by fluid condensation, freezing, or corrosion. Impulse line blocking is a problem that must be addressed to ensure efficient operation and maintenance.

Yokogawa's EJX series DP transmitter is equipped with a silicon resonant sensor that can rapidly detect both static pressure and differential pressure. These features enable the development of a diagnostic technique which detects fluctuations in static and differential pressures. By using a digital communications network such as fieldbus, operators can determine whether an impulse line at a specific installation site has been blocked. Such information can significantly reduce maintenance workload and cost.

Expected Benefits

  • Informs operators/maintenance engineers that a blockage is forming in an impulse line before the process is disrupted.
  • Predicts when the impulse line will be blocked and suggests a corrective action, based on blockage thresholds.
  • Blockage thresholds are determined based on blocking substance, flowrate variation, and the time required for taking corrective action.

Impulse-line-blocking Diagnostic Technique

(1) Fluctuation of differential, static pressures

Table 1. Fluctuating component values in impulse lines

Table 1 Fluctuating component values in impulse lines

Fluctuating components of differential, static pressures generally decrease when an impulse line is blocked.

Fluctuating components are calculated as the square summation of the difference of differential and static pressures that are sampled at very short time intervals. The amplitudes of fluctuating components are derived from the root of the square summation. Since these components are affected by flowrate changes, they are provided as fluctuation components through flowrate compensation.

Table1 shows the value of the fluctuating components when blocking occurs on the Hi-side, Lo-side, and both sides. The values for when no blocking occurs are also shown. When both sides of impulse lines are blocked, all fluctuating components decrease. When one side of an impulse line is blocked, the corresponding fluctuating component decreases. In this case the fluctuating component of differential pressure is larger than when no blockage occurs.

(2) Blocking diagnosis using water flow test rig

Figure 2. Blocking factor F with H and L side blocking

Figure 2 Blocking factor F with H and L side blocking

Blocking factor F is determined as the correlation function between the amplitudes of fluctuating components. It approaches +1 for high side blocking and -1 for low side blocking. Figure2 shows the Blocking factor F for each blocking type.

Conclusion

Operators must receive diagnostic information before a line block leads to a malfunction. Yokogawa provides predictive diagnostics based on trend analysis of the blocking factor, which improves maintenance efficiency and reduces maintenance costs.

Note:

This diagnostic function is currently available for low viscous liquids only.

Verwandte Industrien

  • Chemicals

    Chemical products are indispensable to modern life and industry. Chemical plants, where these products are manufactured, are required to maintain stable operations 24 hours a day, 365 days a year while achieving high levels of safety, productivity, and sustainability. Leveraging more than 100 years of expertise in measurement and control, together with digital technologies such as AI, Yokogawa helps chemical industry customers achieve sustainable growth. Together with Yokogawa, shape the future of your manufacturing operations.

  • Refining & Petrochemical

    The refining and petrochemical industries are facing major challenges from the energy transition, digitalization, and market volatility. To stay competitive, companies must improve operational agility, efficiency, and sustainability. Drawing on decades of industry expertise, Yokogawa helps customers achieve safe, reliable, and optimized operations through advanced automation and digital solutions.

  • Offshore (FPSO, FLNG & FSRU)

    Offshore exploration and production requires maximum uptime under harsh conditions. Manned and unmanned facilities need reliable integrated control and safety systems (ICSS) with advanced remote monitoring capabilities. Yokogawa has state-of-the-art technology and extensive experience in executing offshore projects of all sizes and automation levels of complexity.

    In addition, operators are increasingly seeking digital technologies that improve operational efficiency, reduce offshore manning requirements, enhance safety, and support sustainable operations. Yokogawa combines automation, digitalization, wireless technologies, AI, robotics, cybersecurity, lifecycle services, etc, to help customers maximize asset value throughout the entire facility lifecycle.

  • Upstream

    The upstream industry includes offshore and onshore activities including wellhead automation, fractionation, completion, and separation to recover and prepare underground or underwater crude oil and natural gas.

    As petroleum is brought to the surface, it must be separated prior to transport. Primary and secondary separation stages commonly distribute gas flow, water flow, and oil flow in three phase separation. Gas movement requires pipeline and can include a fractionation process in the upstream stage prior to movement. Liquids can be placed into a tanks or pipelines and sent for processing, requiring accurate level measurements.

Zugehörige Produkte & Lösungen

  • EJX110A

    Differenzdruckmessumformer der EJX-A-Reihe mit traditioneller Montageart

  • EJX115A

    Relativdruckmessumformer der EJX-A-Reihe mit integrierter Strömungsblende

  • EJX118A

    Differenzdruckmessumformer mit Druckmittlern basierend auf der EJX-A-Reihe.

  • EJX210A

    Differenzdruckmessumformer der EJX-A-Reihe für Flüssigkeitsanwendungen mit Flanschmontage

  • EJX438A

    Relativdruckmessumformer mit Druckmittler der EJX-A-Serie

  • EJX440A

    Traditional-mount High Gauge Pressure Transmitter based on the EJX-A Series as a high performance model.

  • EJX530A

    Relativdruckmessumformer der EJX-A-Serie mit Manometeranschluss.

  • EJX630A

    High-End-Relativdruckmessumformer der EJX-A-Serie mit Manometeranschluss

  • EJX910A

    Der Messumformer misst Differenzdruck, statischen Druck und Prozesstemperatur mit größter Genauigkeit und berechnet auf dieser Grundlage den Massenstrom, wobei der integrierte Hochleistungsdurchflussrechner voll kompensierte Werte liefert.

  • EJX930A

    Dieser Messumformer wurde speziell für hohe statische Drücke entwickelt. Er misst Differenzdruck, statischen Druck und Prozesstemperatur mit größter Genauigkeit und berechnet auf dieser Grundlage den Massedurchfluss, wobei der leistungsstarke, integrierte Durchflussrechner voll kompensierte Werte liefert.

Top