I am sorry if this question will seem a bit too easy for you.
But I have been searching online for 2 days now yet I get confused about it all more and more.
Please correct me here.

My understanding is that there are 2 methods to produce steel pipes;
seamless (30 per cent market share)
welded (70 per cent market share)

welded pipes are divided into SAW, SSAW, HSAW and LSAW categories based on pipe's diameter size.
SSAW - small
SAW - normal
LSAW - big
HSAW - no idea ?????

SSAW pipes are used in constructions, SAW pipes are used in water supply sort of projects and LSAW are used for oil and gas pipeline projects.

Q1. Did I get it all correct?
Q2. What is HSAW??
Q3. Where can I find LSAW's market size, market performance, major producers by region and demand drivers?

You guessed it right, school project

Looking forward for your responses.