The difference between a dark rod flange gate valve and an open rod flange gate valve

Gate valves can be divided into the following according to the structure of the valve stem

1. Open rod gate valve: the stem nut is on the valve cover or bracket, and when the gate is opened and closed, the stem nut is rotated to realize the lifting of the valve stem. This structure is beneficial to the lubrication of the valve stem and has a clear degree of opening and closing, so it is widely used.

2. Dark rod gate valve: the stem nut is in the valve body, which is in direct contact with the medium. When opening and closing the gate, it is achieved by rotating the valve stem.

The advantage of this construction is that the height of the gate valve is always the same, so the installation space is small, and it is suitable for large diameter or gate valves with limited installation space. This structure should be equipped with an opening and closing indicator to indicate the degree of opening and closing.

The disadvantage of this structure is that the stem thread not only cannot be lubricated, but also directly accepts the erosion of the medium and is easily damaged.

Main Differences Between Open Rod Gate Valve and Dark Rod Gate Valve:

1. The lifting screw of the dark rod flange gate valve is only rotating without moving up and down, and only one rod is exposed, and its nut is fixed on the ram, and the ram is lifted by the rotation of the screw, and there is no visible gantry; The lifting screw of the open rod flange gate valve is exposed, and the nut is close to the handwheel and is fixed (not rotating or axially moving), and the ram is lifted by rotating the screw, and the screw and the ram have only relative rotational motion without relative axial displacement, and the appearance is a door-shaped bracket.

2. The dark rod valve cannot see the lead screw, while the open rod can see the screw rod.

3. When the dark rod valve is opened and closed, the steering wheel and the valve stem are connected together and relatively immovable, and it is through the rotation of the valve stem at the fixed point to drive the valve disc to lift up and down the gate to complete the opening and closing. Exposed rod valves raise or lower the disc through the threaded transmission between the stem and the steering wheel. To put it simply, the open rod valve is a valve disc that moves up and down together with the valve stem, and the steering wheel is always at a fixed point.

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.

Crown valve pushing.

The functionality is the same.

The only difference is.

The open rod gate valve can be opened from the appearance, whether the valve is closed or open, and the open rod is generally used for fire fighting.

It is clear whether the valve is open or closed at the first time.

The dark rod had to be tried manually.

Summary. 1. The open rod gate valve can see the screw rod, but the dark rod can not see the lead screw; 2. The open rod gate valve is used to lift or lower the valve disc through the threaded transmission between the valve stem and the steering wheel; When the dark rod gate valve is switched, the steering wheel and the valve stem are connected together and relatively immovable, and it is driven by the valve stem to rotate at the fixed point to drive the valve disc to lift up and down to complete the opening and closing; 3. The transmission thread of the dark rod gate valve is located inside the valve body, and in the process of opening and closing, the valve stem only rotates, and the gate plate rises and falls in the valve body; The valve stem of the open rod gate valve drives the gate plate to rise and fall together, and the transmission thread on the valve stem is outside the valve body, and the opening and closing and position of the gate can be intuitively judged according to the movement direction and position of the valve stem; 4. The height of the dark rod gate valve is small; Exposed rod gate valves require a large installation space; 5. The structure of the open rod gate valve is beneficial to the lubrication of the valve stem, and the degree of opening and closing is obvious; The stem thread of the dark rod gate valve not only cannot be lubricated, but also directly accepts the erosion of the medium and is easy to be damaged. Therefore, open rod gate valves are more widely used.

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1. The open rod gate valve can see the screw rod, but the dark rod can not see the lead screw; 2. The open rod gate valve is used to lift or lower the valve disc through the threaded transmission between the valve stem and the steering wheel; When the dark rod gate valve is switched, the steering wheel and the valve stem are connected together and relatively immovable, and it is driven by the valve stem to rotate at the fixed point to drive the valve disc to lift up and down to complete the opening and closing; 3. The transmission thread of the dark rod gate valve is located inside the valve body, and in the process of opening and closing, the valve stem only rotates, and the gate plate rises and falls in the valve body; The valve stem of the open rod gate valve drives the gate plate to rise and fall together, and the transmission thread on the valve stem is outside the valve body, which can intuitively judge the opening and closing and position of the gate according to the movement direction and position of the valve stem. 4. The height and size of the dark rod gate nuclear leakage valve are small; Exposed rod gate valves require a large installation space; 5. The structure of the open rod gate valve is beneficial to the lubrication of the valve stem, and the degree of opening and closing is obvious; The stem thread of the dark rod gate valve not only cannot be lubricated, but also directly accepts the erosion of the medium and is easy to be damaged. Therefore, open rod gate valves are more widely used. Hope mine can help you before you <>

The difference between open rod gate valve and dark rod gate valve1.The screw rod cannot be seen by the dark rod valve, but the screw rod can be seen by the open rod. This is where it is easy to identify;

2.When the dark rod valve is switched and switched, the steering wheel and the valve stem are connected together, so it is actually relatively immobile, what is relatively immobile, I think friends who have studied physics should know it. The dark rod valve is to drive the valve disc to lift up and down the gate by rotating the valve stem at a fixed point to complete the start and close action; Topbar valves raise and lower the disc by threading the stem and steering wheel.

Therefore, it is also easy to distinguish the difference between dark rod and open rod gate valve;

3.The prompt screw of the dark rod gate valve is only rotating, it does not move up and down, only a rod is exposed, and its nut is also fixed on the ram, and the ram is lifted by the rotation of the screw, and there is no visible door clamp. The open rod gate valve is different, the lifting screw of the open rod gate valve is exposed, the nut is subsidized by the handwheel, and it is fixed, the ram is lifted by rotating the screw, the screw and the ram only have a relative rotational motion, and there is no relative axial rotation, and the appearance is a door-shaped bracket.

An open-rod gate valve means that the stem of the gate valve rotates and can be raised and lowered at the same time, so as to infer the opening of the valve.

The stem of a dark stem gate valve rotates and no other sign is visible.

There are several major differences between open rod gate valve and dark rod gate valve:

1. The open rod gate valve can see the screw rod, but the dark rod can not see the lead screw;

2. The open rod gate valve is used to lift or lower the valve disc through the threaded transmission between the valve stem and the steering wheel; When the dark rod gate valve is switched, the steering wheel and the valve stem are connected together and relatively immovable, and it is driven by the valve stem to rotate at the fixed point to drive the valve disc to lift up and down to complete the opening and closing;

3. The height size of the dark rod gate valve is small, and the open rod gate valve requires a large installation space.

The difference between open rod gate valve and dark rod gate valve:

1. The open rod gate valve can see the screw rod, but the dark rod can not see the lead screw;

2. The open rod gate valve is used to lift or lower the valve disc through the threaded transmission between the valve stem and the steering wheel; When the dark rod gate valve is switched, the steering wheel and the valve stem are connected together and relatively immovable, and it is driven by the valve stem to rotate at the fixed point to drive the valve disc to lift up and down to complete the opening and closing;

3. The transmission thread of the dark rod gate valve is located inside the valve body, and in the process of opening and closing, the valve stem only rotates, and the gate plate rises and falls in the valve body; The valve stem of the open rod gate valve drives the gate plate to rise and fall together, and the transmission thread on the valve stem is outside the valve body, and the opening and closing and position of the gate can be intuitively judged according to the movement direction and position of the valve stem;

4. The height of the dark rod gate valve is small; Exposed rod gate valves require a large installation space;

5. The structure of the open rod gate valve is beneficial to the lubrication of the valve stem, and the degree of opening and closing is obvious; The stem thread of the dark rod gate valve not only cannot be lubricated, but also directly accepts the erosion of the medium and is easy to be damaged. Therefore, open rod gate valves are more widely used.

The first-class fire engineer examination memorizes the mantra of the bright rod gate valve and the dark rod gate valve.

The difference between open and dark rods.

Generally, it is used for gate valves, and the so-called open rod means that the stem head will rise and fall when opening and closing the valve. That is, you can see the movement of the valve stem (not rotating, only lifting).The so-called dark rod means that the valve stem will only rotate when opening and closing the valve, but will not rise or fall.

The open rod is the stem head that rises and falls when the valve is opened and closed. That is, you can see the movement of the valve stem (not rotating, only lifting).The so-called dark rod means that the valve stem will only rotate when opening and closing the valve, but will not rise or fall. The model of the open rod is Z44 and the model of the dark rod is Z45.

The most essential difference between the open rod and the dark rod is that the medium of the open rod is not in contact with the valve stem thread, and the dark rod is in contact, and the gate valve of the dark rod is usually used for infrequent opening and closing, and the installation space is small. That is, you can see the movement of the valve stem (not rotating, only lifting).The so-called dark rod means that the valve stem will only rotate when opening and closing the valve.

The valve of the dark rod can also be made into a situation where the stem thread is not in contact with the medium.

The simple identification method is: the dark rod is the stem nut in contact with the medium. The stem nut of the open rod does not touch.