How exactly do you pronounce metal expansion joint codename? Engineers dismantle doorways behind models
When you encounter a metal expansion joint code name, just looking at the alphanumeric combination, Xiaobai is easy to be confused, but the old master can read the pipeline medium, compensation amount and pressure level from the code name-isn't it a little mysterious? In fact, there are rules to follow in code compilation. More than 30 kinds of metal expansion joints are listed in the product catalogue of this site, from general-purpose corrugated expansion joints to high-temperature axial types, from straight pipe pressure balance types to double hinge transverse types. Each code name hides its structural characteristics and applicable working conditions. Don't rush to remember the formula. Let's understand one thing first: code names are not random.
Metal expansion joint codes usually consist of five to eight parts: structural form (e.g., "T" for general purpose, "Z" for straight pipe pressure balance), nominal diameter (DN number), pressure Class (PN or Class), bellows material (304L, 316L, Incoloy, etc.), wave number, and some with connection mode (flange or welding) and compensation direction. As an example, our common "universal corrugated expansion joint" codename may start with "T" or "TB" followed by DN200, PN16, 304L, 10 waves – get it? Each symbol corresponds to a technical parameter.
But don't be too happy, the codes under different manufacturers and different standards vary greatly. The national standard (GB/T 12777) has a set of recommended formats, but many established manufacturers follow their own code system. For example, the "high-temperature axial expansion joint" of this station often has "G" or "W" in its code name, emphasizing the temperature resistance grade; The "large-diameter thick-walled expansion joint" will mark the wall thickness and reinforcing ring parameters separately. When selecting a model, you can't just look at the code, but also compare the product parameter table. Two days ago, I met a customer and asked a "HZ-500-1.0-6". When I saw it, it was a double hinge transverse expansion joint, DN500, 1.0MPa, 6 waves. He didn't recognize it, and almost installed it on a high-temperature steam pipe as a general-purpose type.
Why do some codenames look garbled? Because too much information is compressed. For example, "ZP" or "PP" are commonly found in the code of "straight pipe pressure balance expansion joint", followed by "L" to indicate the number of tie rods and "H" to indicate the hinge structure. And "curved tube pressure balance expansion joint" will be distinguished by "QP". If you see the "D" beginning, it is mostly "electric plug-in insulation door" or "double-seal single-axis circular flapper door"-no, that's the code name of flapper door, not belonging to metal expansion joint. It's a joke if you get mixed up.
To really make good use of the code name, we have to judge it according to the working conditions. The same code name "T-300-1.6-8" is fine when placed on the normal temperature water pipe, but if it is used in the flue gas system of power station with a medium temperature of 600℃, it must be replaced with "high-temperature axial expansion joint" or "corrugated expansion joint for power station industry". The code name of "Metal Corrugated Expansion Joint in Cement Industry" in our station usually has "SN" or "CM", which is specifically aimed at high-temperature dust environment. The selection error is often not that the code cannot be read, but that the symbol is read but the following working condition description is ignored-for example, is there a deflector? Is the material corrosion resistant? These details are in the technical agreement outside the code name.
Metal expansion joint codenames are a stepping stone to model selection, but not all. Look at the structural form letters first, then check the nominal diameter and pressure, and finally turn the material and wave number. It doesn't matter if you can't remember it. Just send the code to the manufacturer's technician. However, you can watch it yourself, at least you can avoid being fooled-guess what? Some people take the code name of "general-purpose type" to pretend to be "pressure-balanced type" and sell it at a high price. This kind of pit has been seen more than once. So next time you get the code name, don't nod in a hurry, break apart each paragraph and ask clearly, it works better than anything else.
Attachment: Common product codes on this site for reference
- Universal Corrugated Expansion Joint-T-Head
- High Temperature Axial Expansion Joint-G/W-Start
- Straight Pipe Pressure Balanced Expansion Joint-ZP/PP-Start
- Compound Hinge Transverse Expansion Joint-HZ-Start
- Curved Tube Pressure Balanced Expansion Joint-QP-Start
- Large diameter thick wall expansion joint with wall thickness parameters
- Metal Corrugated Expansion Joint for Cement Industry-SN/CM-Beginning
Remember, code names are just indexes, and it's the design parameters and material choices behind them that really determine performance. Next time you get the model number, check the structure diagram according to the product page of this site, and then call the technical confirmation.