Steel Production and Pipe Thickness

Unfortunately you are correct, what we you are mentioning is the result of quality american manufacturing facilities being sent to china, they do not have stringent quality manufacturing processes, and unfortunately, there is very little if any american manufacturers of Piping, or Pipe fittings, this problem has become more noticeable in the last 5 years, as most of the fittings we can actually buy now are from china, or taiwan, unfortunatley taiwan has higher quality than china if that tells you were we are headed. if you want to verify just request the MTR's with fittings or piping and you will see that it all traces back to China.

VMG

I suspect you are talking about Seamless pipe and/or drill casing as opposed to ERW or SAW pipe.

The welded pipe consistently has had tighter tolerances due to the rolling mill and the skelp produced.

I have worked at USX USS Lorain in the seamless mill off and on for years and find the tolerances have greatly improved. (as low as 2% opposed to AMSE and API Standards).

But, I also find that pipe from India and The Mediterranean nations still has a way to go to achieve the tight tolerances the domestic plants have achieved.

In the PetroChem sector I seldom see Chinese manufactured pipe unless it is smaller bore, but I do see some odd instances of ERW in larger bores for Powerplants.

I am refering to smaller bore piping, and pipe fittings,

most of my experience is with pressure control Piping, and Fittings, and much against my will my company decided to save money by getting, Korean, chinese, and taiwan piping and fittings, until we had a serious incident that made them see thing my way.

we now only accept piping, and fittings from G8 Countries, but getting it is not that easy, we have looked for domestic manufactureres but have had luck only with higher pressure piping and fittings, I still have not been able to find a domestic manufacturer of Low Pressure Pipe Fittings, Threaded, Socket Weld or butweld, we had to settle with taiwan for low pressure fittings,

I have seen the small bore fittings give fitters and welders fits at various vendors also, both threaded and welded.

That along with porosity and the various inclusions.

Chinese has been the worst, I agree with vendors telling me it is still cheaper to inspect them and toss the 50% or so that are not quite suitable.

Seems to me they forget the Inspection, Fit-up, and Welding costs.

I commend you for taking the stance you have and buying as you do.

chinese products are of bad quality. China has the bad reputation that they can supply the items with stamp of any country. Recently Indian customs seized items imported from CHINA but with made in India stamps. The products were similar to MICO BOSCH products.

Around 15 years ago , in a big project in Sud America (Venezuela) we had to much problems with chinesse flanges. These flamges were jacketed and welded at the ends to meet the required Sch. At that time, only for this project, we removed more than a 1000 flanges (do you remenber?). Also, be carrefull with Rumanian plates Sa 516 Gr 70.

DEAR,

I M A INDUSTRIAL - HYDRAULIC ENGINEER, BUT BEFORE THAT I WORKED WITH STEEL TUBES & PIPE (SEAMLESS, ERW, SAW PIPES, SPIRAL) MANUFACTURING PLANT.

IF U HAVE ANY DOUBT U REFER ASTM BOOK WHICH RELEASE UR CONFUSION, BECAUSE IF WE SEE ANY THING FROM OUT SIDE WE WILL BE CONFUSE, BUT U GO IN SIDE U WILL DEFINITELY GET RESULTS IN PERSANTAGE.

BECAUSE I CANT DEFINE A ASTM BOOK WHICH SHOWS DIFFERENT STANDERD FOR DIFFERENT PROCESS & STANDERD ALSO.

Pipewelder didn't mention the weld lands that vary from razor to 1/8 in in the same piece; makes getting a reliable full penetration without burn-through so much fun for the guys in the weld shop. The weld bevel preps that are nowhere near even for that blind-drunk amateur look so sought after by our customers. Then the hard spots in the material that grenades the tooling when you're machining to finish. Or the inclusionary matter that always seems to show up at the most inopportune times - thank you Murphy. But it's all to "spec"!