Reading Level: Intermediate

One of the tasks of civil engineer is the project management. Wherever a project commence, it is starting of ‘live’ of project problem until it has been completed build. Below are some of common problems that civil engineer may faced:

1. Project commenced without acknowledgement of civil engineer. It is common especially for small scale of project; such as single unit of structure like bungalow. Engineer will only alert whenever problem is happened at site; and problem is unable to resolve it by contractor. Contractor will like to build it without interruption of engineer.
2. Even though civil engineer aware about the construction work, some of un- responsible contractor will try to do some work in the time that engineer is unable to present. As for example; contractor carry out the concreting work after office hour especially in the evening, nighttime and public holiday. Once concreted, engineer is unable to inspect it.
3. Whenever construction started, un-experience contractor will do work by referring to civil engineering drawings without read in-conjunction with other professional drawing such as architecture, mechanical and electrical drawings. As a result, there will be a number of hacking during or after completion of structural works. It incurred a number of arguments and costs.
4. Even though an inexperience contractor is read engineering drawings, somehow contractor is build to their own knowledge; especially from contractor previous project. If previously contractor had been built a number of pad footing foundation, contractor obtain a piling foundation project. The contractor will try to change it to pad footing foundation by his own knowledge. Or even in pad footing foundation, contractor will change pad footing to smaller size. It will end up with structural problem.
5. Some irresponsible contractor will ignore engineer instruction. Contractor will build to his own knowledge. Contractor will always persuade client that contractor is builder. Contractor tells client that he is more site experience than civil engineer. Engineer has not much site building experience. Most of the time, client will agree with contractor because contractor shown client with physical construction works and engineer without much of physical product. These will continue until problem happened and unable to resolve by contractor. Finally, they will seek for engineer advice.
6. Contractor perform cost cutting on project work. Now days, project cost is very competitive. In order to obtain a project by bidding, some contractor may lower down the bidding cost to below the cost. When project is awarded, contractor will perform unnecessary cost cutting. This will endanger client.
7. When client is contractor and contractor is client, civil engineer will be in difficult position on dealing with client and contractor. There will be always in conflict of interest.

These problems may faced by civil engineer. How to overcome them will mainly base on engineer experience. Junior engineer shall not advice to send them to resolve these matters. Anyway, junior engineer shall be in guidance of senior engineer whenever problems are being solved.

Seamless pipe vs welded pipe

1. The difference in production process

Welded pipe: The steel plate or steel strip is used as raw material, and it is welded after being crimped by the unit and mold. According to different welding methods, it can be divided into straight seam welded pipe and spiral welded pipe.Seamless steel pipe: It is made by cold rolling, cold drawing or hot extrusion production process using round steel perforation as raw material.2. The difference on the outer surfaceWelded pipe: The steel pipe has high precision, uniform wall thickness, high brightness inside and outside the pipe, and can be arbitrarily cut to length; it can be used as a thin-walled pipe.Seamless steel pipe: The steel pipe has low precision, uneven wall thickness, low brightness on the inside and outside of the pipe, high cost of sizing, and there are pitting and black spots on the inside and outside that are not easy to remove. Usually the pipe wall is thick.3. The difference in performanceSeamless steel pipes are much higher than welded pipes in corrosion resistance and pressure and high temperature resistance.With the improvement of welded pipe manufacturing technology, the mechanical properties and mechanical properties are slowly approaching seamless pipes. In some aspects, welded pipes can replace seamless pipes.4. The difference in priceThe production process of seamless steel pipe is more complicated, and its price is more expensive than welded pipe.5. The difference in applicationSeamless steel pipe: It has a hollow section and is used as a pipeline for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames, and steel scaffolding used in construction. Steel pipes are used to make ring parts, which can improve material utilization, simplify manufacturing procedures, and save materials and processing. Working hours.

Welded pipe: its pressure-bearing performance is general, mainly used to transport water, oil, gas, air, and heating water or steam and other generally lower pressure fluids.

Tips:ASTM A53covers seamless and welded steel pipe with nominal wall thickness. The surface condition is usually black and hot-dipped galvanized. ASTM A53 is produced mainly for pressure and mechanical applications, and is also used for transport of steam, water, gas line pipes.

ASTM A53 ERW steel pipe is a typical carbon steel pipe(CS ERW pipe). It is largely used to convey fluids at low / medium pressures such as oil, gas, steam, water, air and also for mechanical applications.