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Non-Intrusive Acoustic Valve Inspection

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Presentation on theme: "Non-Intrusive Acoustic Valve Inspection"— Presentation transcript:

1 Non-Intrusive Acoustic Valve Inspection
(NAVI) Theory & Applications Mohammad Nazri Mudin Amserve Engineering Sdn. Bhd.

2 VALVE PASSING Refers to flow through a valve which is set in the “off” state (closed). FACTORS IMPACT Seat alignment Insufficient actuator travel Poor maintenance Corrosive and/or erosive process media Valve seat is prevented from fully closed due to dirt/rust. Safety Environment Production Asset Integrity Amserve Engineering Sdn. Bhd.

3 NON-INTRUSIVE ACOUSTIC VALVE INSPECTION (NAVI)
Technology from France Used widely in Nuclear Power Plant to detect passing valves and steam traps Experience more than 20 years Europe, North America, Africa No permanent installation required Inspection is fast and reliable Estimation of leak rate based on actual data collected Amserve Engineering Sdn. Bhd.

4 WORKING PRINCIPLES Based on passive measurement of ultrasonic acoustic emission. These sounds are generated by the flow of fluids through leaking valves under pressure. The NAVI hardware takes the sound measurement signals, processes and displays them as a signature most suitable to identify and quantify the leaks. Test requirements Valve to be tested must be in closed position There is a differential pressure across the valve, at least 1 barg. Amserve Engineering Sdn. Bhd.

5 THEORY OF APPLICATION Acoustic emission is a structure borne noise and it is generated by the process medium flow. NAVI detects leak noise caused by turbulent flow, which is measured in decibels (dB). If a valve is in open position, there will be laminar flow that generates little or no noise. A tight valve makes a very little or no noise. A passing valve creates turbulent flow and acoustic noise. The AE is transmitted into the valve body. Amserve Engineering Sdn. Bhd.

6 INSPECTION TOOL Hardware Panasonic Toughbook Model CF-19/Getac
Touch-sensitive screen Acquisition card up to 2400 kHz Intrinsically safe (Zone II) Software & Accessories Digital NAVI Analyzer Contains database, current and previous. Piezoelectric accelerometer and heat sink compound Sensor Cable/Sensor Heat Sink Compound Amserve Engineering Sdn. Bhd.

7 AE MEASUREMENT 2. Place sensor on the upstream piping, take background noise. 1. Place sensor on the valve body, take pressure noise. 3. Place sensor on the downstream piping, take background noise. Amserve Engineering Sdn. Bhd.

8 Background Noise (Dwn)
DATA ACQUISTION Background Noise (Up) Pressure Noise (Body) Background Noise (Dwn) Amserve Engineering Sdn. Bhd.

9 ANALYSIS Differential Signature VALVE PASSING Analysis
Background Noise (Up) Pressure Noise (Body) Background Noise (Dwn) Differential Signature VALVE PASSING Analysis If Pressure Noise is greater than Background Noise, then the valve leaks. If Pressure Noise is equal to Background Noise, then the valve is tight. Amserve Engineering Sdn. Bhd.

10 ANALYSIS Differential Signature VALVE TIGHT Analysis
Background Noise (Up) Pressure Noise (Body) Background Noise (Dwn) Differential Signature VALVE TIGHT Analysis If Pressure Noise is greater than Background Noise, then the valve leaks. If Pressure Noise is equal to Background Noise, then the valve is tight. Amserve Engineering Sdn. Bhd.

11 Continue Monitoring 6-Monthly Estimation of Leak Rate
ANALYSIS PASSING NO PASSING Continue Monitoring 6-Monthly Small Medium Large Large Leak – 24 dB and above Valve recommended to be replaced Small Leak – 1 to 9 dB Continue Monitoring 6-Monthly Medium Leak – 10 to 23 dB Valve Need Repairing Estimation of Leak Rate Tolerable Leak Threshold for Various Type of Valves (Shell IMP 3.02 Table 1) Amserve Engineering Sdn. Bhd.

12 CASE STUDY 1: LAUNCHER PRESSURE BUILT UP RECTIFICATION (EXTRACT FROM CLIENT REPORT)
JANUARY 2013 Amserve Engineering Sdn. Bhd.

13 CASE STUDY 1: LAUNCHER PRESSURE BUILT UP RECTIFICATION
Trunkline RY (Launcher L-2900) and Trunkline RZ (Launcher L-2910) found high pressure build-up in launcher barrel (up to 80 barg/day) after pigging activities. After lubrication & sealing, RY launcher pressure build up controlled at 1 – 2 barg/day. RZ launcher pressure build up higher at 3 – 5 barg/day. Further rectifications was requested to verify root cause. Action Items: Mobilized Amserve to conduct non-intrusive acoustic valve inspection on MOVs to determine leakage rate; and check for any passing from kicker line and vent line. Mob valve maintenance vendor to conduct MOVs alignment, perform greasing and sealing. Amserve to verify passing valves and final leakage rates. Amserve Engineering Sdn. Bhd.

14 CASE STUDY 1: LAUNCHER PRESSURE BUILT UP RECTIFICATION
MOV290X2 MOV290X1 Non-Intrusive Acoustic Valve Leak Inspection was performed on MOV290X1, MOV290X2 Kicker Valves (VX-2901, VX-2902) Equalizing Line Valves (VX-2904, VX2905) Vent Valves (VX-6395, VX6396) Amserve Engineering Sdn. Bhd.

15 CASE STUDY 1: LAUNCHER PRESSURE BUILT UP RECTIFICATION
NAVI Result for RY (L-2900) No serious passing detected from kicker valves, equalizing line valves and vent valves. Pressure build up not likely contributed from these valves. MOV290X2 (riser side/tee) passing rate still within allowable limit, but the high dB ratio indicate ACTUAL passing rate could be higher than the estimation. MOV290X1 (launcher side) passing rate exceeded allowable limit, but lower than MOV290X2. CONCLUSION: Build up of pressure in launcher is likely from MOV290X1 and MOV290X2. Amserve Engineering Sdn. Bhd.

16 CASE STUDY 1: LAUNCHER PRESSURE BUILT UP RECTIFICATION
TOLERABLE LEAK THRESHOLD (SHELL IMP 3.02 TABLE 1) Item Types of Valves Tolerable Leak Threshold Warning Limit (% TLT) Gas service (kg/s) Oil service (kg/s) 1 Riser ESD Valves (1) 0.1 75 2 Launcher/Receiver 1st MOV (at barrel) (1) 0.01 50 3 Launcher/Receiver 2nd MOV (at barrel) (1) 4 Process ESD Valves (SDV, ROV) (2) 5 Depressurization or Blow-down valves (3) 0.03 6 Motorized Isolation Valves (MOV) (4) 0.01, 0.1 50, 75 7 Process Control Valves and FCV (5) 8 Mechanical Isolation Valves (6) 9 Integral DBB Valves (7) 10 Non Return or Check Valves (8) 0.3 Note: Based on consequence of 2 mm pinhole leak with 5 m jet fire as per Riser Tolerable Leak Rate Study Rev.0 Mar 2008. Rate of 0.1 kg/s is based on the worst case consequence similar to Riser ESD valves with blow-down duration of 15 min or more and 0.3 kg/s for case with depressurization less than 10 min from maximum operating pressure to 7 barg. Rate is based on flaring limit of 0.1 MMscfd of one valve or 2.0 MMscfd for total valves of the platform. Rate is based on consequence cases similar to Pig-trap valve, i.e. last barrier 0.01 kg/s and otherwise 0.1 kg/s. Only for FCV and those process control valves that serve also as shutdown valves (no other Process ESD valves) and rate shall follow the Process ESD valves. Rate is based on consequence cases similar to Motorized isolation valves. Rate is based on consequence case similar to last barrier of MOV, i.e kg/s Rate is based on the consequence of blow-down valves. Amserve Engineering Sdn. Bhd.

17 CASE STUDY 1: LAUNCHER PRESSURE BUILT UP RECTIFICATION
Result after cleaning and re-sealing Pressure built up contained to 0 barg after 2 days of monitoring (2 barg after 4 days). NAVI was conducted again, result shows MOV290X2 is still passing and confirmed by continuous passing of gas at body vent. MOV290X1 shows minimal passing, and greatly reduced passing from body vent. Most of riser pressure is being contained by MOV290X1. MOV290X2 shall be replaced as soon as possible. MOV290X1 shall also be considered for replacement. Without sealant, leakage will become worst. Amserve Engineering Sdn. Bhd.

18 CASE STUDY 3: TO IDENTIFY PASSING CHECK VALVES FOR P-6250
JAN 2013 Amserve Engineering Sdn. Bhd.

19 CASE STUDY 2: CHECK VALVES
System Area: M1 P-6250 Situation: Pump suction check valves and pump discharge check valves were suspected passing, however could not be identified. Action Items: Amserve to carry out NAVI. Pump was let run until reach consistent desired discharge pressure, then stopped to create backflow. Result: Passing valves were identified. Leak severity ranged from small to medium leak, however estimated leakage rates are still within tolerable leak threshold for check valves (0.3 kg/s). Amserve Engineering Sdn. Bhd.

20 CASE STUDY 3: VALVE PASSING VERIFICATION FOR A NEWLY INSTALLED VALVE AT TML PLATFORM
MAY 2012 Amserve Engineering Sdn. Bhd.

21 CASE STUDY 3: TML NEWLY INSTALLED VALVE
System Area: TML’s BR-A Pipeline Isolation Valve Situation: During recent shutdown, a new valve was installed to replace previously reported passing valve. During pressurization, pressure build-up was observed at the downstream. Client requested for verification and estimation of leak rate, as not to exceed the standard allowable leak rate* (1 kg/min for natural gas). Action Items: Amserve was notified on the situation and was mobilized to site. Result: It is found that the valve passing and the estimated leak rate is still within the allowable leak rate. OIM and maintenance team were notified on our findings. Amserve Engineering Sdn. Bhd.

22 BENEFITS Identify passing valves. Safety Environment
Avoid unnecessary valve repair Identify repeat leaking valves Identify leaking valves to increase efficiency Safety During maintenance, ensure effective isolation. Environment Reduced flaring/emission Amserve Engineering Sdn. Bhd.


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