2-bolt flange: new eco-materials? 

This is a topic that comes up more and more often in negotiations with customers, especially from Europe. Everyone talks about “environmental friendliness,” but when it comes to specifics—say, that very two-bolt flange for piping a small pipeline or device—confusion begins. Many people immediately think about some revolutionary biopolymers, forgetting that the basis of environmental friendliness in our industry is often not the material itself, but the entire life cycle of the product: from smelting and forging to installation and, importantly, disposal. Let's understand without loud words.

What is really hidden behind ?eco? in metalworking

When I hear “new eco-friendly flange materials”, my first thought is either a marketing effort or a request to reduce the carbon footprint of the production chain. In the case of forged flanges, and weShanxi Hongkai Forging Co.,LtdWe deal with them, the conversation is rarely about replacing steel with something fundamentally different. Steel means reliability, standards (the same GOST, ASME), tested for decades. The question is different: how to make the process of obtaining and processing it less resource-intensive?

For example, one of the real trends is the use of steel produced using technologies that reduce CO2 emissions (so-called “green steel?”). But its availability and, most importantly, certification to specific standards (say, for a flange for a welded ring according to EN 1092-1) is a separate headache. We tried to negotiate a batch of such steel for the manufacture of flat flanges DN150. The price soared by 25-30%, and the supplier could not guarantee that all mechanical properties would be identical to the usual steel grade 20 (or A105) without lengthy tests. The project was frozen.

Therefore, now the more realistic path is not so much new material as optimizing the existing one. Metal recycling, energy-efficient furnaces, minimizing waste during forging - this is what gives a real environmental effect. And here it is precisely important that the manufacturer, whether in China or in Europe, has a well-functioning technological cycle. On our websitehkforging.comWe don’t write loud slogans, but in the section on production you can see that modern forging and pressing equipment is not only about accuracy, but also about the efficient use of energy.

Practical case: when is ?eco-friendly? flange creates problems

I’ll tell you about one case that well illustrates the gap between theory and practice. We were contacted with a request to produce a batch of loose flanges (sliding) according to DIN 2642, but using “lightweight?” aluminum based alloy. The customer's idea was to reduce weight and, as he believed, to be “environmentally friendly?” due to lower metal consumption.

We have produced prototypes. Mechanical processing was difficult - the material was “sticky”, the tool wore out faster. But the main problem was revealed later. These flanges were designed to be connected to conventional steel butt weld flanges. The different coefficient of thermal expansion during cyclic heating in the hot water pipeline led to leaks appearing at the connections after six months. The aluminum-steel galvanic couple also showed itself in the presence of a coolant. The result is complaints, dismantling, replacement with standard steel flanges. The environmental benefit from saving several kilograms of metal on a product was completely outweighed by the need for early replacement and disposal of “innovative” ones. details.

This experience has established a rule for us: any deviation from proven materials and standards must be technically and economically justified up and down. Environmental friendliness should not go against reliability.

Recycling as part of sustainability

An often missed point. The most “green” a flange is one that has served its purpose and can be 100% remelted without loss of quality. With forged steel flanges that meet standards, this is the case. Their material is valuable secondary raw materials. But with the same coatings or composite inserts (which are sometimes offered to “improve” characteristics) difficulties begin. Their separation makes recycling unprofitable or even impossible, sending the product to a landfill. Therefore, our approach when manufacturing non-standard products according to customer drawings is to avoid as much as possible one-piece combinations of dissimilar materials, unless this is critically necessary.

Where to look for real improvements: the manufacturer's view

Based on our experience as one of the manufacturers in the forging and pressing center, real environmental friendliness is laid down at the design and pre-production stage. That's what we pay attention to.

Firstly, this is an accurate calculation and optimization of the workpiece. Modern software for forging simulation allows you to minimize burr (technological waste of metal). For large flanges, say in the DN1000-DN4000 range, savings of a few percent of the workpiece weight translates into tons of steel saved per batch. This is a direct environmental and economic effect.

Secondly, this is logistics. Manufacturing a flange in a region with developed metallurgy and forging (as in our Shanxi province) reduces the transport footprint compared to the situation when blanks are transported thousands of kilometers for processing, and then finished products back to the consumer. The full cycle in one place, which our company has, is a plus.

Thirdly, durability. The most environmentally friendly product is the one that does not break. Therefore, our priority is strict adherence to heat treatment technology and quality control at all stages. A flange that lasts 30 years instead of 20 already makes a huge contribution to reducing overall resource consumption, even if it is made from classic carbon steel.

Conclusions: are there new materials?

Returning to the title question. If we talk about fundamentally new materials that will massively replace steel in manufacturingflanges 2 boltsand other types - this will not happen in the foreseeable future. Reliability, standardization, predictability of behavior in critical conditions - there are no alternatives to steel yet.

But ?new eco-materials? — rather, it’s a new approach to old material. Is it ?green? steel as it matures technologically and commercially. It is the intelligent optimization of the entire production cycle to reduce energy consumption and waste. This is designing a product taking into account its entire life, including disposal.

For manufacturers like our company, environmental friendliness today is not about writing a nice word on a websitehkforging.com. This is about the daily work of engineers and technologists to ensure that everyoneforged flange, whether standard to ASME B16.5 or custom to drawing, was not only of high quality, but also produced with minimal environmental impact. And this is perhaps the most honest and practical understanding of ?eco? in our industry at the moment.