ADVANCED OILFIELD DOCUMENT N0. TECHNOLOGY COMPANY AOTC/WP040 PAGE No:LLC 2 of 6 Advanced oilfield Technology Company LLC. Post box:1693, RUWI, Postal code:112, Sultanate of Oman WORK PROCEDTel: UR2450 E 3744; Fax: DA2450 TE : 3757. 07 07th MarchMarch 2011 REVISION No. : 0 Email:
[email protected]
WORK PROCEDURE AOTC/ FORMAT 0/ REV-0
SUBJECT:
METHOD STATEMENT FOR CONTROL VALVES
DOC. NO.: AOTC/WP -
0 REV. No.
QC Engineer DATE
PREPARED
QA Engineer
Manager QA/QC
REVIEWED
APPROVED
ADVANCED OILFIELD TECHNOLOGY COMPANY LLC. WORK PROCEDURE
DOCUMENT N0. AOTC/WP- 040 DATE : 07th March-2011
PAGE No: 2 of 6 REVISION No. : 0
1. SCOPE: The purpose of this Method statement is to provide a controlled procedure for overhauling and testing of control valves in line with industry standards.
2.
Reference Standards: ASME : American Society Of Mechanical Engineers. API 6D : Petroleum and natural gas Industrial pipeline transportation system valves. API 598 : Valve inspection and testing ANSI / FCI 70-2 : Leak testing of control valves
3. Abbreviations: ASME – American Society Of Mechanical Engineers API –American Petroleum Institute. ANSI – American National Standards Institute. AOTC – Advanced Oilfield Technology Company
4. Responsibilities: Test Engineer: Maintains the status of the control valve. Coordinates with the client. Supervises the over all activities. Allocating time for each job and maintaining the delivery time. Supervisor: Identifying the nature of repair work to be carried our. Execution of job. Maitaining the right methodology of work. Coordinating work the technicians and the engineer. Recording all the work carried out . QC Engineer : Carries out initial inspection of the incoming valves. Prepares initial finding report with remedial action. Witness activities at different stages. Selection of right metallurgy. Witness bench set, Leak test & Integrity test.
5. Test standards:
ADVANCED OILFIELD TECHNOLOGY COMPANY LLC. WORK PROCEDURE
DOCUMENT N0. AOTC/WP- 040 DATE : 07th March-2011
PAGE No: 2 of 6 REVISION No. : 0
API -6D API -598 ANSI/FCI 70.2 ASME B16.5
6. Equipments: 1. 2. 3. 4.
Control valve test benches. Loop calibrator Multimeter Hart Communicator.
7. Types of control valves 1. 2. 3. 4. 5. 6.
Ball valve V- Notch Ball valve Globe Valves Butterfly valve On-Off valves Choke valves
8. Types of actuator 1. 2. 3. 4.
Single acting pneumatic actuator for linear application. Double acting pneumatic actuator for linear application. Single acting pneumatic actuator for rotary application. Double acting pneumatic actuator for rotary application.
9. Sequence of activities
ADVANCED OILFIELD TECHNOLOGY COMPANY LLC. WORK PROCEDURE
DOCUMENT N0. AOTC/WP- 040 DATE : 07th March-2011
PAGE No: 2 of 6 REVISION No. : 0
Collection of valves: Valves are brought to the facility. Job card is opened for the concerned valve.
Inspection : The control valves reaching the AOTC valve facility will undergo general visual inspection. Valve accessories like positioners, relays, boosters, limit switches, will be inspected and reported in the AOTC report. Careful examination of the valve body, flange face will be carried out. •
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Initial Functional Test: Actuator functional test is carried out first. The actuator will be given min and max operating pressure. The findings will be recorded in the AOTC report. leak test will be conduct by applying pressure on upstream side and the test findings are reported in the AOTC report. Bench set is carried out to check the proper opening of the valve in 0 – 100%. Stroke test is carried out for positioners and the travel of the valve stem is noted at 0 % , 25% , 50%, 75% , 100% by giving 4-20 mA signal through the feeder. •
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Dismantling : Prior to dismantling the valve will be punched. Remove the accessories & tubings from the actuator and positioner. De couple the coupling and remove actuator from valve body Remove compression on actuator spring by screwing spring adjuster until the actuator tension is free. Loose the bolts of the Actuator casing and remove the actuator. Remove O-rings, seals and any soft parts Remove the bonnet or side casing from the valve body. Take out the complete trim set from the body. Separate out gasket , packing , valve trim components and place them is separate trays for inspection. • •
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ADVANCED OILFIELD TECHNOLOGY COMPANY LLC. WORK PROCEDURE
DOCUMENT N0. AOTC/WP- 040 DATE : 07th March-2011
PAGE No: 2 of 6 REVISION No. : 0
Overhauling stages: All the parts will be carefully inspected and the inspection findings will be entered in the AOTC report . Necessary repair work will be carried out. •
Trim set inspection: 1. Carefully examine contact area and plug contact area. Lapping will be carried out if required. 2. Examine stem gland area. 3. Examine stem thread area. 4. Examine cage, cage, ball, seat ring, seal ring. 5. Examine gasket sealing surface. Body inspection: 1. External and Internal body is carefully examined for cracks and cavitation. 2. Examine seat pocket area. 3. Examine gland area and gland packing. Replace gland packing if necessary. 4. Examine gland studs, gland follower, gland bush. 5. Examine all the greasing point and apply grease where ever necessary. 6. Examine body studs and nuts. Actuator inspection: 1. Check for bends and score marks. 2. Check for spring wear and tear. Advice for painting if its in bad condition. 3. Check for corrosion 4. Check for cracks in casing. 5. Check for conditions of pressure and sealing soft goods.
Overhauling Stages: All parts will be placed in separate trays . Trays will be tagged by the valve tag No or serial number for identification. Heavy valve body will be placed in separate stand in upright position. 1. Cleaning All the parts will undergo cleaning by using appropriate cleaning agent. 2.
ADVANCED OILFIELD TECHNOLOGY COMPANY LLC. WORK PROCEDURE
DOCUMENT N0. AOTC/WP- 040 DATE : 07th March-2011
PAGE No: 2 of 6 REVISION No. : 0
Assembly:
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Assemble the trim set, stem plug in the valve body. Place the gland packing and gland follower. Close the bonnet of the valve. Assemble the actuator on the valve body. Place the O ring on the actuator stem. Place the diaphragm plate and the diaphragm. Close the casing. Adjust the spring tension screw. Tighten the yoke lock nut screw.
Final Testing: Actuator functional test is carried out first. The actuator will be given min and max operating pressure. The findings will be recorded in the AOTC report. leak test will be conduct as per ANSI/FCI 70-2 by applying pressure on one side and the test findings are reported in the AOTC report. Bench set is carried out to check the proper opening of the valve in 0 – 100%. The valve will be then calibrated using Hart communicator. The findings will be recorder in the AOTC test report. •
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Dispatch: The tested ok valves will be kept in another area for dispatch The tested valve will then be dispatched to the client along with all the test reports. • •
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