Regarding 8-character blind plates

8-character blind flanges are widely used in chemical processing plants, especially in polymerization plants, the petrochemical industry, and the graphite industry. They are particularly used between main systems and auxiliary systems. Although they are not considered extremely critical equipment, they are very important during operations. I remember a colleague I worked with at the same company saying that when handling 8-character blind plates, they had to fill out production records and work orders, and only after getting approval from their supervisor could they proceed ； I don’t know if it’s true.

Could the original poster share some information on Mechanised line blinds for everyone to see?

I’ve been trying to send it for half a day without success; let me figure it out first

It must be pretty expensive, right? In our factory, the so-called \"eight-character blind plates\" are basically created by the construction team: they find a steel plate with the appropriate thickness and cut it into a blind plate for use. . It will be very expensive. . I guess our factory won’t use it. . HOHO. . The factory is really cheap.

The 8-character blind plate has a simple structure and a low price. Manual switching in special situations plays a crucial role in ensuring safety. A new product can only replace the existing 8-character blind plate if it outperforms it in all aspects.

http://bbs.hcbbs.com/viewthread.php?tid=384109&extra=page%3D1&frombbs=1

The structure of the information provided by the original poster regarding Mechanised line blinds is too complex. The 8-character blind plates are used for safety reasons during maintenance; what’s needed is something simple and reliable. Only if it can provide reliable sealing at a low cost, and thus replace both the manual control valve and the 8-character blind plate, then it could serve as a substitute

Personally, I think 8-character blind flanges are quite good – they’re safe and reliable. If the price offered by the original poster is not appropriate, I don’t think many people will use them. The 8-character blind flanges we use in our company work well, and we have no intention of looking for alternatives, as that would increase our costs

Yes, it’s extremely uneconomical in terms of cost. Replacing a blind flange costs only about a hundred yuan according to the standard rates, and it’s usually replaced only during maintenance – that is, once a year or even once every few years. Which company would consider using such a valve? And if the valve can indeed provide such a good seal, then there is no need to use a blind flange.

I think if that new product has the following advantages, it could replace the 8-shaped blind flange: 1. Low cost 2. Good sealing performance 3. Easy maintenance 4. It can be locked when closed, preventing it from being opened arbitrarily. Indeed, when an 8-shaped blind flange is closed while the machine is in operation, opening it requires approval and signature from the relevant supervisors.

Personally, I believe that the mechanized line blinds provided by the poster simply cannot replace the 8-shaped blind plates. These 8-shaped blind plates have a simple structure, are inexpensive, safe, and reliable; they are not devices that are used frequently, yet they are crucial for the entire production process. In current domestic production facilities, they cannot be replaced. At least that’s the case in our company.

I agree with everyone’s views to some extent, but I am also aware of the situation in some companies. I’m not sure if everyone is familiar with the 8-character blind plate; as we all know, it is a variant of flange connections. Used for isolation in partitioning systems or non-operating systems. In the polymer and graphite industries, catalyst and additive systems often require blind flanges to be replaced due to changes in product types. The operation isn’t very complicated, but it is time-consuming and also results in waste of materials ； Additionally, 8-character blind flanges are generally used in conjunction with valves. Taking costs into account, it should be the cost of 8-character blind plates + valves = Mechanised line blinds ； The safety and automation of operations are particularly important, especially when it comes to the use of 8-shaped blind flanges in toxic gas piping systems. In the gas systems of the metallurgical industry, there is a type of valve known as a “goggle valve”. Its function is similar to that of mechanized line blinds, but its diameter is much larger than that of mechanized line blinds. It is widely used, and as far as I know, this type of valve is also beginning to be utilized in the petrochemical industry. In my opinion, such valves have clear advantages in applications involving frequent switching of 8-shaped blind flanges and in pipelines transporting hazardous materials.

Regarding the above 4 points, as far as I know, except for the first one, the rest are all advantages of this product； It is conceivable that the first factor is something that none of the new products possess, and it is also a major reason why new products cannot be quickly accepted. But I also agree that spending more money in this area requires considerable determination from managers. Also, as far as I know, BASF has products for this purpose

I thought of another application scenario: on high-temperature pipelines, it is quite troublesome to operate the 8-shaped blind valve installed there when turning it around; one has to wear protective gear and remove the insulation layer, and sometimes the high temperature requires a long period of isolation, which is time-consuming and labor-intensive； At this time, such products have a great advantage. And the effect is more pronounced in accident conditions. I’m not sure if my analysis is correct I’m asking everyone again!

There was thorough discussion and differing opinions; perhaps this is precisely what constitutes the advantages and disadvantages of such things

I think so; price is an issue

It’s too complex; it’s neither economical nor suitable as a replacement for 8-character blind plates