Sep 22, 2010
1. When the product is corrosive to the piping system. Products containing chlorides and other salts can attack the tubing and fittings used to transport the products throughout a plant. Systems fabricated from 304 or 316 stainless steel can become leaky after prolonged contact with salty food and beverages, e.g. sports drinks and soy sauces. If the product is...
Sep 17, 2010
Unexpected or premature failure of chemical process equipment constitutes a serious hazard in terms of personnel, plant, and environmental safety. By weakening reliability, such failures also adversely affect productivity and profitability. Modern experience in chemical plants has been that failures due to environmental cracking are among the most serious of such problems, making up about 20 to 30% of all corrosion failures. The purpose of this article is to discuss in simple terms some of the pertinent information.
Aug 26, 2010
An MTR (Material Test Report, or Mill Test Report) is a quality assurance document that lists the chemical composition of a particular material, which is identified by a heat number. It also contains information such as mechanical properties like strength, elongation, hardness and other applicable industry standards. MTRs are typically required for all tube, fittings, and components to be used in high purity systems.
Jul 16, 2010
True or False: I don’t need to buy weld insert rings with AL-6XN tubing and fittings. I can make field welds that look fine without using weld rings. I hope you answered “False.” Although AL-6XN can be field welded without using filler material, it’s risky business to put those welds into corrosive service.
Jul 6, 2010
The other day a customer called me and wanted to purchase fittings that are made in the USA. So, I did some research to find out where some of the major fitting manufacturers make their fittings. Here’s what I found: Bradford fittings are made in Thailand and Canada. Top Line fittings are made in China. VNE fittings are made in Israel and Germany, but the...
Jul 6, 2010
Have you ever experienced weld puddle shift? Have you ever wondered why ASME BPE limits sulfur for tube and fittings to .005% to .017%? Take a look at these videos, and you’ll understand why. Clip 1 shows matched sulfur of .008% on both weld pieces. Clip 2 shows mismatched sulfur of .002% welded to .014%. Notice how the weld pool tracks off-center of...
