I. What kind of metal expansion joint does the export market need? Don't just focus on product parameters
Do metal expansion joint export, what are you most afraid of? I'm afraid that you will take the domestic parameter list and run to the customers in the Middle East to say, "Our product has a pressure of 1.0MPa and a temperature of 200℃", and people will shake their heads directly. Why? Because the demand for metal expansion joints in the export market is not a number game on the parameter sheet at all. What customers really buy is "service life" and "no accidents at the scene".
Last year, there was a chemical plant in Southeast Asia that wanted to purchase a batch of general-purpose corrugated expansion joints. The quotations of several domestic factories were similar. Where did the winning bid win? Win a calculation for customers-the humidity in the local rainy season is more than 85% all the year round. If the bellows material is only ordinary 304, the pitting rate will soar directly after two years. Eventually they recommended the scheme with a chloride-resistant coating, which was 15% more expensive, but the customer said it was "worth it".
Are there chloride ions in the medium? Is there any sulfide? Is the pipeline overhead or buried?This information directly determines which product you want to use: is it a corrugated expansion joint for the power station industry, or a lining piece matching the desulfurization flue gas baffle door? "One size fits all" is the most taboo in the export market.
Second, the selection is not to copy the domestic experience-how to match the high temperature, high pressure and corrosive environment?
Friends who are used to routine working conditions in China are prone to rollover when they encounter the high temperature conditions of export orders. For example, the design temperature of steam pipelines in the Middle East can reach above 550℃, and the general-purpose corrugated expansion joints commonly used in China can't bear it at all. At this time, high-temperature axial expansion joints must be used, and the bellows material must be upgraded to Incoloy 800H or 625 alloy. More importantly, many domestic manufacturers are too lazy to calculate the creep and relaxation properties of materials at high temperature, but the owners in export projects often ask for detailed stress analysis reports.
Let's talk about corroding the environment. It is common for paper mills in Southeast Asia and mining projects in South America to contain sulfuric acid and hydrofluoric acid in media. At this time, ordinary metal expansion joints will definitely not work, so you have to use PTFE-lined hose or PTFE compensator. But the problem is: the process of lining PTFE is divided into two kinds: molding and welding. If the welded lining is not handled well, the wrinkles on the flange surface will leak first. Our experience is that for negative pressure pipelines, molded integral lining must be selected, otherwise it will be too late to cry if it is deflated.
There are also high pressure operating conditions. External pressure single axial expansion joint or straight pipe pressure balance expansion joint are commonly used for expansion joints above PN25 in China. However, when exported to Europe and America, many projects require to be designed according to ASME B31.3, and the wall thickness, wave height and wave pitch have to be recalculated. You just take the parameters calculated by the national standard JB/T, but people don't recognize them.
III. Technical standards and certification: Do the CE and ASME you got really work?
These days, any export-oriented factory can take out CE certificates. But have you really looked carefully at the standard number on the certificate? Many CE certificates are made according to EN 14917, which is mainly for metal bellows expansion joints, but if you export rectangular expansion joints or non-metal expansion joints, they are not right at all. There is also ASME U stamp-don't think that just stick a label. ASME certification requires that every product be supervised by an authorized inspector (AI) on the spot, and records must be kept of wave pressure test and airtightness test. ASME certificates issued by some small factories are actually "self-declaration", and the customs check them accurately.
In addition, Russia and CIS countries require EAC certification, and Saudi Arabia in the Middle East requires SASO. You said that these certifications are troublesome, but there is no way-without it, the goods will be deducted directly when they arrive in Hong Kong, and the detention fee will top you half a year's profit a day. Therefore, the first thing to do when engaging in the export of metal expansion joints is not to find customers, but to find out the entry threshold of the target market first.
Fourth, the pits of quality inspection: guide tube, tie rod, weld, where is the most prone to problems?
Something that looks perfect in the production workshop will show its original shape as soon as it gets on board. I've seen too many claims for export orders, concentrated in three places.
The first isguide tube。 Many people think that the deflector is just a steel pipe sleeve, and it can be welded. Wrong! The directional arrow of the deflector is marked backwards, causing the media to flush the bellows and perforate within a year. We suggest to check the coaxiality between the guide tube and the shell separately before leaving the factory, especially for large-diameter thick-walled expansion joints. If the eccentricity of the guide tube exceeds 2mm, it cannot be shipped.
The second istie rod。 How to adjust the tie rod nut must be clearly written in the factory manual. Once, the double hinge transverse expansion joint sent to India, the customer directly used the tie rod as a fixed bracket on the spot, and the bellows cracked. After repeated tearing, it was found that the limit nut of the tie rod was not coated with anti-loosening glue when it left the factory, and it was loosened due to shipping bumps. Since then, the tie rod nuts on all of our expansion joints have been added with double nut locking plus red scribed marks that can tell at a glance if there is any displacement.
The third isweld。 Export products usually require 100% radiographic or penetration testing. However, small factories often only sample inspections, or use ultrasound instead of radiation. To be honest, the root cracks of longitudinal seams and annular seams of bellows are difficult to interpret by ultrasound. Don't save that flaw detection fee. Once the customer finds that the porosity of the weld exceeds the standard, the whole batch will be returned.
V. Packaging and logistics: How to carry the metal expansion joint when it bumps for 3,000 kilometers in the container?
The metal expansion joint looks strong, but in fact, it is very precious. The wall thickness of the bellows is only 0.5mm to a few millimeters, and it will deform if it is bumped slightly. I once unpacked a package shipped to South America, and a pit was smashed directly into the bellows-the reason was that the wooden box was not securely secured, and the deflector hit the bellows.
The outer surface of all bellows must be wrapped with anti-rust paper + bubble film, and then fixed with nylon cable ties. For large-diameter thick-walled expansion joints, it is recommended to make a special iron frame, and lock the flange bolt hole with the iron frame to prevent transverse movement. In addition, the humidity in the shipping container is high, especially on the tropical route of the Panama Canal, and the rust-proof packaging is not in place. After arriving at the port, the flange surface is rusty and the tie rod is rusty, so customers directly refuse to accept it.
Many customers require expansion joints with transport limits, such as locking nuts on tie rods or temporary support plates. These items must be clearly labeled "removed after transportation" in the installation instructions. Otherwise, the workers install it in a daze, and as soon as the system heats up, the bellows will be directly pulled out.
6. Customers want more than just products: after-sales response and localized service are the keys to repurchase
Many manufacturers export metal expansion joints, and there is no following after selling out one order. Guess why those international EPC general contractors would rather spend more money than choose European and American brands? Because of a phone call, the local engineer will arrive at the scene within 48 hours. What about us? The customer sent an email asking how to replace the deflector, and the reply had to be jet lag. Want to repurchase in this situation? Difficult.
Each export project is provided with a "fool-like" installation and maintenance manual, bilingual in Chinese and English, accompanied by tutorials. If the customer can't install it on the spot, direct video connection guidance. In addition, we found local cooperative agents in major markets (Southeast Asia and the Middle East) for warehousing and simple maintenance. Although the initial investment is large, the return rate of old customers has been pulled from 15% to more than 40%. The customer said it well: "Although you are selling metal expansion joints, I bought them without causing me trouble." Is that the truth?