Valve issues on the torch main pipe

It is recommended to use a butterfly valve! Due to the large diameter, using a gate valve results in high equipment costs, and gate valves are also non-standard equipment!

We use butterfly valves for the following reasons: 1. With such a large diameter, the cost of the valve, its size, and the difficulty of operating it make it unsuitable; 2. The pressure in the flare system is very low, so there is no need to use gate valves for shut-off – butterfly valves are sufficient for this purpose. The valve we use in our equipment is a butterfly valve, but it’s DN800 size

:L Why don’t the torch main pipes I’ve seen have any valves? ! Is there any special purpose to installing a valve?

I use eccentric hard-sealed butterfly valves here. The effect is good. Can large-diameter gate valves be operated? The valves on the flare line generally do not move. It’s just that a transmission mechanism is added, and in the end it neither saves effort nor labor – the DN500 flare line gate valve we installed earlier is an example of this. Furthermore, sediment tends to accumulate in the gate valve grooves, making it harder to seal properly, especially in refineries that engage in coking. It’s not as good as a butterfly valve. The specifications state that valves should not be installed on the flare line; their use is necessary only when the facility needs to be shut down or started up separately, and this practice is seen only in large plants.

Our factory’s torches also use butterfly valves! Another point is that in the 1930s, the butterfly valve was invented in the United States; it was introduced to Japan in the 1950s and became widely used there in the 1960s. In China, its adoption started after the 1970s. Currently, in the world, butterfly valves with a diameter of DN300 millimeters or more are gradually replacing gate valves. Compared to gate valves, butterfly valves have a shorter opening and closing time, require less force for operation, need less installation space, and are lighter in weight. Taking DN1000 as an example, the butterfly valve weighs about 2 tons, while the gate valve weighs about 3.5 tons. Moreover, the butterfly valve can be easily combined with various driving devices, and it boasts good durability and reliability. ?

However, butterfly valves also have a problem: in some flare pipelines, the fluid flowing through them is not clean and contains a large amount of particles, which continuously scour the valve disc. This leads to wear and damage of the sealing surface as well as the valve disc itself, resulting in poor sealing. There is now a type of valve called a hemispherical valve that is suitable for such conditions; it’s worth considering

We use ball valves on the vent lines of our natural gas processing unit, also of DN1000 size. The number of flares is determined primarily by the number of operating units in the treatment system. The venting pressure generally ranges from over 11 MPa to atmospheric pressure, with daily production amountsing to tens of millions of cubic meters; the instantaneous venting pressure surge is very high. Given that ball valves have the least impact in this context, they are chosen for use, and it takes several minutes to open or close them once.

Many torches are shared by several units; when one of these units is shut down for maintenance, the supply is cut off

Use a butterfly valve! Key considerations: 1. Cost: Gate valves are too expensive ； 2. Easy to operate: With low pressure, the butterfly valve can be used fully, making operation very convenient!

It is recommended to use butterfly valves, as they are easier to operate

Hehe, I see. Our main torch pipe is usually a single one, and there definitely shouldn’t be any valves installed on it.

The flares in our area are for decorative purposes; their diameter is not large, being less than DN200, and they generally do not come equipped with valves during design； (Should a gate valve or a butterfly valve be used for the valve on the torch main pipe, DN1000?) It’s almost certain that a butterfly valve will be chosen in this case; I’ve tried to open a gate valve with a diameter of DN300, and it was difficult to do so even with two people using a lever – especially when there is a high pressure difference or after the valve has not been opened for a long time. Moreover, it is well known that gate valves are prone to internal leakage. From an economic perspective as well, it’s not a cost-effective choice ； Butterfly valves are cost-effective and offer sensitive operation; they represent the best choice between the two types of valves when low pressure and sealing requirements apply.

Valves are generally not used for isolation on torch pipes; instead, a water seal device should be employed for isolation.

Butterfly valves – the analysis provided by my friend upstairs is quite good

After considering the opinions and suggestions of everyone, it is recommended to use butterfly valves. The problem now is that although butterfly valves are indicated in the flow diagram, the piping team used gate valves by mistake. These gate valves have already been delivered to the site, and since they are the only DN1000 pipe in the installation, they cannot be used elsewhere. Ordering new ones from the manufacturer would take too long. Let’s prepare to replace the butterfly valve with a gate valve first! Could there be security issues? This post was last edited by mallon on 2009-4-14 18:59.]

The pipes in my system carry fluid from the outlet of the separator tank to the flare. How can a water seal be used to create a separation? Could you provide more details or some relevant information? Thank you! !

Some design firms now recommend the use of triple-eccentric butterfly valves. I’m wondering how these would perform in situations involving particles. Do any of you have experience in this area?