Author: Jethro

Minimum Required Documentation for Supplying Materials

Building plant requires a lot of paper works such as QCP, ITP, Manufacturing Procedure, Sub-vendor list, Mechanical Book, Installation Manual, Quality Assurance Record, MTC and so on. Due to the reason, some suppliers are having difficulties especially for start new companies. Each document has specific purpose of use, for example ITP(Inspection Test Plan) is to check inspection plan how, what and...

Titanium Tube Crack

The crack on the titanium tubes which is the surface of condenser, was found during the commissioning. There are a few causes of tube damage which may occur by one or more combined mechanisms during operation as below. Erosion at steam side Damage by impact Condensate corrosion Stress corrosion cracking at steam side Fretting and fretting corrosion from tube vibration Tube impact damage from tube ...

Corrosion, and Painting Failure

The purpose of painting is to prevent corrosion from moisture, acid gas, or other factors. So, we apply varnish coating, galvanizing, or anti-corrosion coating for steel products. However, applying any kind of painting doesn’t guarantee anti-corrosion. On CS structure of CT equipment, we found progressing corrosion. The facilities are installed in the seawater and every steel structure is ex...

Pitting on the Surface of HIC(Hydrogen Induced Crack) Plates

Pitting or Pitting Corrosion is well known quality failure which we can find on the surface of steel products. Every steel products have stabilized surface which doesn’t response to oxygen or other acidic gas. Harden surface made by heat treatment protects products from those gases. By some reason, however, if surface got damaged, scratch, pock etc the area exposed to O2, H2O, H, then ion re...

Cause of Rust on the Surface Painted

Steel products easily get rusted unless it’s stainless steel. There is many efforts to prevent rusting for example painting, varnishing, or rust transforming for the rust already have. Most of all, it would be better not to have the products rusted. However, sometimes we can find wave mark rust on surface after we applied anti-rust materials. It’s normally caused by moisture in the mat...

Pressure Vessel Hydro Test Failure

Hydro test is mandatory for pressure vessels and we see often test failure in many cases. This time we found the failure during the test due to heavy load and weak ground holding the equipment. At the stage of start, everything was fine however, the ground holding the equipment wasn’t solid enough and the ground finally collapsed. The weight of the pressure vessel including water was appx. 8...

Excessive Lubricant on Surface and Its Result Caused by.

Lubricant is being used to reduce heat and friction during production in steel business area. It prevents deformation by reducing heat and friction. However, using excessive lubricant especially remained on the surface of products can cause serious problem. Welding is one of very common method to assemble or install steel products at job site. And welding needs high temperature flame. Most of lubr...

Pipe Line Coating Failure Modes

Coating is one of main methods to protect pipe line from corrosion. It defenses pipes from moisture, dirty, acid and any kind of chemical action. It gives longer life time of pipe line. However, some failures could jeopardize project and make people get injured due to explosion or any other unexpected events. There is several reasons of failures such as air permeation, water permeation, loss of ad...

Grain Size and Mechanical Properties

Grain size is the main factor of deciding mechanical properties of materials. Grain size has its boundaries and it’s connected to the others. If the boundraies are big, materials can be easily broken. And grain size is attributed by heat treatment. If materail has bad heat treated or non-heat treated, we can’t have structure that we intended to have. Ferritic structure is changing by t...

The best way to make longitudinal fin tubes for Cu-alloy

There is several ways that we can choose to make longitudinal fin tubes for Cu-alloy. And I’m going to introduce the best option among them. We’ve tried many times to get a good result and failed many times too. And finally we found the best way without failure of quality.   The first one is lead soldering. The melting temperature of lead is 327.5°C and the environment of the tube...

Spring Hangers, PWHT, Prevention of Metal Fatigue

Fluids always have vibration and it can cause metal fatigue. Eventually it causes serious damages on steel products, structure of buildings or facilities. Any structures, especially pipe lines are exposed to vibration. And we have been trying to prevent it. Technically, it can’t be prevent so we decide to let it happen by using device, such as Spring Hangers.  Without Spring Hangers, structu...

A Case of Pipe Failure

There is several reasons of crack on pipes, such as unexperienced welder, design error, metal fatigue, poor management, material failure etc. One cause can make a crack or sometimes it happens by combined reasons or chain reaction. The picturs below, an engineer posted and asked questions to other engineers the reason of pipe failure. Size of the pipe attached to main pipe is 3″ STD. He didn...

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