Tuesday, June 27, 2017

American Welding Society Welding Symbol Chart

American Welding Society Welding Symbol Chart



Monday, March 28, 2016

Turtle Attack


Wednesday, November 18, 2015

How PSV works ?

Basic Operation

Below Set Pressure With Main Valve Closed


At Set Pressure


Set Pressure at 110%


Below Set Pressure


POP Action Pilot


Modulating Action Pilot


Thursday, October 22, 2015

Pressure Safety Valve(PSV) Test Incident

What happened?

A Pressure Safety Valve (PSV) was taken to the PSV workshop to be re-certified. The PSV was attached to the bench with a Teflon adapter and pressurized for leak test.
Initially all PSV testing crew remained outside the PSV test container, while air increasing pressure to the PSV. Once the pressure reached 140 bars and stabilized, 3 PSV testers went into the PSV container and used soapy water to test the leak around the PSV. Shortly after the commencement of the leak check, the Teflon (PTFE) adapter failed resulting in ejecting. 



What went wrong? 

Using substandard material, e.g., self-made PTFE adapter gasket (failure to identify the limitations and characteristics of PTFE). 

Factors contributing to this incident:

-PSV tester indicated that they had used similar adapters on other jobs before.
-There was no technical evaluation or Management Of Change (MOC) applied to the use of Teflon (PTFE) as a adapter piece.
-The machining of the adapter piece did not conform to designs to reduce stress points.
-The location of the Test bench did not allow ease of alignment of the PSV.
-The Contractor does not have a written and approved Procedure for the testing of PSV’s.

Recommendation:

-Only standard material shall be used for the PSV testing and high pressure operations.
-Relocate test bench to center of the container, ensuring full assembling/removal of clamp arms is possible.
-Management of Change procedures shall be applied if there must be any changes from standard procedures, requiring full evaluation of the proposal, including Risk Assessment.
-Written & approved Procedures shall be in place for all activities and communicated to concerned parties.


Wednesday, October 21, 2015

Habitat


NDT (Non Destructive Testing)










 






All Nondestructive testing will be carried out in full compliance with requirement of ASME 31.3.

Weld examination shall be performed in accordance with following standards

-Visual : ASME Section V, article 9
-Radiographic : ASME Section V, article 2
-Magnetic Particle : ASME Section V, article 7
-Liquid Penetrant or Dye Penetrant : ASME Section V, article 6
-Ultrasonic : ASME Section V, article 4

Note :
1) 100 %RT for lines subject to pneumatic tests unless otherwise 10 %RT (minimum) is required.
2) 5 %RT (minimum) is required.

Radiographic Testing. 

-This module presents information on the NDT method of radiographic inspection or radiography.
-Radiography uses penetrating radiation that is directed towards a component.
-The component stops some of the radiation. The amount that is stopped or absorbed is affected by material density and thickness differences.
- These differences in “absorption” can be recorded on film, or electronically.





Magnetic Particle.


-Magnetic particle inspection can detect both production discontinuities (seams, laps, grinding cracks and quenching cracks) and in-service damage (fatigue and overload cracks).
-Basic Procedure and Important Considerations
1.Component pre-cleaning.
2.Introduction of magnetic field.
3.Application of magnetic media. (wet or dry)
4.Interpretation of magnetic particle indications.

How does it work?




 A ferromagnetic test specimen is magnetized with a strong magnetic field created by a magnet or special equipment. If the specimen has a discontinuity, the discontinuity will interrupt the magnetic field flowing through the specimen and a leakage field will occur. Finely milled iron particles coated with a dye pigment are applied to the test specimen. These particles are attracted to leakage fields and will cluster to form an indication directly over the discontinuity. This indication can be visually detected under proper lighting conditions.




Magnetic Particle.


Advantage.
-Fast method of inspection and indications are visible directly on the specimen surface.
-Considered low cost compared to many other NDT methods.
-Is a very portable inspection method especially when used with battery powered equipment.
-Can inspect parts with irregular shapes easily.

Limitation.
-Cannot inspect non-ferrous materials such as aluminum, magnesium or most stainless steels.
-Some parts may require removal of coating or plating to achieve desired inspection sensitivity.
-Limited subsurface discontinuity detection capabilities. Maximum depth sensitivity is approximately 0.6” (under ideal conditions).
-Post cleaning, and post demagnetization is often necessary.
-Alignment between magnetic flux and defect is important.




Dye and Liquid Penetrant Inspection

Advantage 

-The method has high sensitivity to small surface discontinuities.
-The method has few material limitations, i.e. metallic and nonmetallic, magnetic and nonmagnetic, and conductive and non conductive materials may be inspected.
-Large areas and large volumes of parts/materials can be inspected rapidly and at low cost.
-Parts with complex geometric shapes are routinely inspected.
-Indications are produced directly on the surface of the part and constitute a visual representation of the flaw.
-Aerosol spray cans make penetrant materials very portable.
-Penetrant materials and associated equipment are relatively inexpensive.

Disadvantage

-Only surface breaking defects can be detected.
-Only materials with a relatively nonporous surface can be inspected.
-Precleaning is critical since contaminants can mask defects.
-Metal smearing from machining, grinding, and grit or vapor blasting must be removed prior to LPI. --The inspector must have direct access to the surface being inspected.
-Surface finish and roughness can affect inspection sensitivity.
-Multiple process operations must be performed and controlled.
-Post cleaning of acceptable parts or materials is required.
-Chemical handling and proper disposal is required.

 Ultrasonic inspection





–Ultrasonic testing uses high frequency sound energy to conduct examinations and make measurements.
–Ultrasonic examinations can be conducted on a wide variety of material forms including castings, forgings, welds, and composites.
–A considerable amount of information about the part being examined can be collected, such as the presence of discontinuities, part or coating thickness; and acoustical properties can often be correlated to certain properties of the material.









Thursday, October 15, 2015

Skin Burned from Chemical Exposure (Potassium Hydroxide)

What happened?

n Electircian, the injuried person (IP) had removed a battery from battery container in order to replace a new battery for fire water pump. Suddenly, while he was removing a battery, the battery dropped into container caused to cap opened and electorlyte leaked at the working area. The IP informed another guy that liquid leaked and then he used water to clean up the working area and battery container. After ensure that the working area is clear and clean, the IP continuely worked by sitting on the soaked floor which his knee and skin exposed with contaminated water (electrolyte + water) until he felt pain on his leg. He flushed the body skin by running water and see the doctor at clinic. The IP suffered serious skin burn (3rd Degree bruned). 

Fire water pump

Battery located and opened cap on top 

Skin burned on leg 

 

What went wrong?

-IP was continuely work by sitting down at the working floor which expose with contaminate water (electrolyte + water).
-IP did not wear chemical suit  when changing  a battery.

Factors contributing to this incident:

-IP did not aware of chemical hazard.
-Limitation for working  area caused IP has to still working on contaminated area.
-There is no chemical protective suit when working with chemical.

Recommendations:

-Providing a proper first aid after exposed to the hazardous chemical.
-Proper PPE have to provide and suit for hazardous chemical.
-To ensure SDS is available at the working area and strictly followed.