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CHAPTER 9. Piping and fittings
Pros: • • • • •
•
Cons: • • • • • •
Mechanical solidity. Stable in sunlight. Universally available. Direct connection to accessories. Can be welded. Although much of the protection against corrosion is lost on welding, accessories, anchors and elbows can be welded at almost any angle. Joining with concrete. This is the pipe to use to pass through concrete walls in tanks and other components. In this case, the minimum wall thickness should be 30cm.
Suffers from corrosion. More expensive. Is not inert. GI pipe consumes chlorine and reacts with water. Tends to leak. Threaded unions become a little impractical for diameters over 150mm. The tools needed for cutting, threading and joining are expensive above certain diameters.
Types of joints: Threaded. The pipe is threaded on both ends and is joined using threaded ring (sockets).
The join should be made using Teflon tape for smaller diameters and natural fibre material for larger diameters, placed along the threads for water tightness. If the wrenching tools are not used correctly, the pipe is left with teeth marks and scratches.
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