• Datasheet of the valve and approved drawings
• Offer list and correlation on the nameplate or tag
• Approved ITP/QAP
• MTC’s and lab test check reports
• Applicable NDT and test procedures
• Type test and fire test compliance
• NDT personnel qualifications
• Calibration certificates for measuring instrument and gauges
How to do the inspection of casting and forging?
• Raw material inspection and heat chart review
• Material identification, sample drawing, and mechanical testing
• NDT: surface defects – Wet fluorescent MPI for forging and casting
• Hardness and surface roughness
How to do the inspection of Block, gate, globe, butterfly, check, and ball valves?
• The castings and forgings must be inspected
• Pressure testing of the valves must be done like the shell, back seat, low and high-pressure closure.
• Fugitive emission testing
• Cryogenic and low-temperature testing
• Visual and dimension inspection as per the datasheet drawings
How to do the inspection of the pressure relief valves?
• Inspection of forgings
• Pressure testing of PSV, body, and nozzle
• Functional test of PSV- set pressure test, set tightness test, back pressure test.
• Visual and dimensional inspection
How to do the on stream inspection of the control valve?
• Correct relief device must be installed
• Check if the pressure settings are proper
• Look for any leakage
• Gas, blinds, closed valves, or piping obstruction should not exist
• The seals that protect the spring must not be broken
• Check if the relief devices are leaking or not
• An ultrasonic test must be done
How to ensure safety during the inspection of control valves?
• Before we remove a valve from the line that section of the line containing the valve must be blanked from all sources of harmful liquids, gases, or vapors. So this part of the line must be depressurized and purged of all oil, toxic, or flammable gases. The inspection tool must be checked before the inspection.
How to do the inspection of a defective valve?
• Check the plant inspection log and also check the equipment inspection so that the valve failure symptoms can be determined
• The temporary repaired materials should be removed like clamps, plugs, etc.
• Inspect the valve for mechanical damage or for corrosion
• Check the bolts and nuts for corrosion
• Check if the build-up area has a proper thickness and also check the quality of the valve body
• Check if the gate or disc is properly secured to the stem
• The guides on both the gate and body must be checked for corrosion
• We should check the gland follower, if the follower is adjusted all the way down then additional packing will be required
• Check if the valve can be operated easily if not then the packing may need to be replaced
How to inspect a rebuilt or repaired control valve?
• If the parts of the valve are replaced then verify if the correct parts are installed
• We must also check if the trim material of the valve is proper for the type of service
• We must do a hydro-test so that we can determine if the repaired valve is suitable for the operation
• Seat tight test must be performed on the valve that needs tight shut off if the trim has been repaired or replaced
• If the gasket and the packing has been renewed then a tightness test must be conducted
Post time: Mar-11-2021