DN200 butterfly valve valve can only turn part of the way

To see if the stem is rotating, if the stem is not turning, it is easy to deal with, that is, the key at the junction of the stem and the handle is gone, buy a key and install it, if you are afraid that the stem will also turn, then it will be troublesome, that is to fix the positioning pin of the stem and the butterfly plate, if it is a hard seal, remove the valve, close the butterfly plate in place by hand, weld the connection between the valve stem and the butterfly plate, but you should also buy a valve back as soon as possible to replace it, because the valve stem may be stainless iron, or it may be 45 steel, these two materials are very brittle after welding, It's easy to break, maybe the valve stem will be broken that day, and then buy it for fear of affecting your construction, so it's better to buy a valve back early and prepare to change it.

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

Is it a turbine butterfly valve or a clamp butterfly valve?

The inlet and outlet control valves of the pumps in the fire pump room should be gate valves, and butterfly valves can be used in other places.

1. Butterfly valves are generally used in places with narrow operating space, if the space does not affect the opening and closing of the gate valve, the gate valve is still selected, and the gate valve is better in terms of sealing and operation performance, and the opening and closing are relatively fast.

2. However, in many cases, the gate valve cannot be installed, or it is not easy to operate after installation, so it is necessary to choose the butterfly valve, but to choose a brand with guaranteed quality.

Marking valve [DN200 flange telescopic butterfly valve product features:] 1. Unique structure, flexible design, light weight, labor-saving, rapid opening and closing 2. Telescopic butterfly valve can not only compensate for the thermal expansion and cold contraction caused by the temperature difference of the pipeline, but also provide convenience for the installation and replacement of maintenance valves.

3. The sealing part can be adjusted and replaced, and the sealing performance is reliable.

DN200 flange telescopic butterfly valve has the following characteristics: 1. Unique structure, flexible design, light weight, labor-saving, fast opening and closing.

2. The telescopic butterfly valve can not only compensate for the thermal expansion and cold contraction caused by the temperature difference of the pipeline, but also provide convenience for the installation and replacement of the maintenance valve.

3. The sealing part can be adjusted and replaced, and the sealing performance is reliable.

Butterfly valve 1DN200 means that the nominal diameter (outer diameter) is 200, which can be operated frequently, so it is an intrinsic fire safety type. There is no phase jamming between the butterfly plate and the sealing ring.

Minimal liquid accumulation at the pipe orifice and stable sealing performance.

Middle. The sealing surface of the butterfly plate is a conical convex upward, which can transport mud, and can achieve good sealing and low fluid resistance under small volume and low pressure. Three-dimensional eccentric sealing system coupled with an optimized design. Under high temperature and high pressure conditions, it is labor-saving, convenient and fast to open and close. The valve closing process is done by elastic pressure on the seal.

Solids do not easily accumulate on the sealing surface. The stem shaft diameter seal is made of graphite pressed into a shaped sealing ring, and the rear is zero leakage. The sealing performance of the valve is not affected by temperature changes, and the metal seal plus before the fire is lightweight.

3.Its special sealing system guarantees high sealing performance in all temperature ranges, from cryogenic to ultra-high temperatures.

The opening resistance of the valve is small, and each point on the circumferential surface of the butterfly plate is separated from the sealing ring at the same time when it is opened.

Suspect you confusing two things.

One is the bellows expander, which is often used to cross the settlement joint (expansion joint) and play the role of longitudinal expansion adjustment compensation; One is the butterfly valve, which plays the role of a switch. The two have different functions, so how can they be combined? And the two together are no better than separate, and I have never seen anything called it like this.

Check it again.

It's as simple as buying a damper and installing it on the air pipe Manually adjust the opening size of the damper to a suitable position, which can control the opening speed of the valve.

Dampers are pneumatic components, not the kind of dampers you think. It is equivalent to a shut-off valve, and those who have done electrical may know it. Not expensive, more than 20 on the market.

Pneumatic valves usually have a quick shut-off function, and the speed of electric valves is correspondingly much slower than the opening and closing speed of pneumatic valves. In this case, like you said, there are three ways to solve it:

1) See if the valve is equipped with a fast exhaust valve, if it is installed, remove it, the speed will be much slower;

2) Another way is to adjust the pressure of the air source of the intake air to a lesser extent, for example, the normal pressure is left and right, which can be adjusted to;

3) Install a positioner to control the flow of the medium in the valve, the flow rate is small, and the impact force on the pipeline is not so great.

Equipped with a relative size of the pipe diameter. DN200 butterfly valve.

The size of the butterfly valve DN200 means that the pipe with a diameter of 200 can be connected. Use a butterfly valve as big as the pipe diameter. In the case of PE pipes, the temperature of the medium should not be high, and the butterfly valve with soft seal DN200 can be used.

I haven't heard of this requirement, in the past, the quality of the ball valve butterfly valve was not up to par and was rarely used, but now it is good to use, but the butterfly valve ball valve is not easy to control the flow and play a closing role, which is more time-saving and labor-saving, and the fluid resistance is smaller. In HVAC, the branch pipe is to control the flow rate, so it is more reasonable to choose gate valves and globe valves, and now there are many ball valves.

HVAC butterfly valves are flanged connections. The pressure bearing capacity is stronger than that of gate valves and globe valves. For the sake of connection safety, the wire connection of gate valve and globe valve is not used.

It's not a valve problem! It's the relationship of **!

I don't know why it's designed. Provide you with some information for your reference, I don't know if it is useful for you 1, the globe valve and gate valve are very expensive, DN50 or more can make a lot of money 2, the butterfly valve is only DN50 or more, there is no small one, there may be, but I almost can't see it on the market.

3. Globe valves like DN150 and DN200 are very large, while butterfly valves are relatively lightweight, and the installation can save block costs, and the valve itself saves too much cost.

4. However, most of the butterfly valves are not closed tightly after a long time.