Welding Pipe and Galvanizing Issues

Hi,

Is it a water supply or sewer pipe? is it possible to use heavy duty PVC pipe in this part of the job? then by using flanges change it to galvanized pipe.

Good luck

hi,

Thanks for reading,These pipe are fabricated as guide pipe through which 100 dia cable is to be pass.these cables hold the 150mt segment to the main pilon at center.to prevent corrosion in sea condition it is to be galvanised.I think i made my point

Looking forward for your rresponse

with regards.

please can you say the size of pipe

hi,

Thanks for reading.the size of pipe is Od-273,8thk and it is to be embeded in concrete(In concrete segment).to prevent rusting and corrosion in sea condition it is suggested to galvanize.

looking for your response.

With regards

galvanizing of any MS metals including the threaded area is very less and thickness of coating is in microns only. ( hardly 0.50 kg per sq. meter) Hence should not pose any problem while coupling it. In fact most of the bolts / nuts are either zinc coated, cadmium or nickel coated. U an go ahed with welding and coat it later also.

sridhar

hi shridhar,

thanks for your response.looking forward for your future assistence.

with regards.

If it is to be used as a cable duct, would plastic be a better proposition?

My experience in Power Stations is that we tried to avoid using metal pipes immersed in concrete. In older power stations they used segmented clay pipe to run cable in. It doesn't corrode and is relatively easy to draw an electrical power cable through. The modern power stations in Australia use a plastic pipe. This has no corrosion problem and is even easier to draw the cable through.

It may be that in India it could be possible to have a potter make the short lengths (approximately 1 metre) of clay pipe so that one end will fit inside the tail end of the last pipe. If a water tight joint is needed it can be sealed with concrete, rubber O rings or silicon sealant.

Galvanised pipe in a salt water environment has a limited life or will require lots maintenance in the form cleaning and painting to protect it.

For mild steel welded piping system, required to be galvanized after welding, I prefer to use flanged connections that easly assembled after welding and galvanizing. A lot of projects had been designed by that procedure like as fire fighting systems, cooling circuits, ... etc.

I have used this method many times with great success. We always power brush the coupling connections or if possible tap or die may be used depending on your specific application.

Mark