Who can tell me which valves have the function of regulating flow?

Classification: Education/Science >> Technology >> Engineering Technology Science

Problem description:

There are many kinds of valves, but which valves can adjust the flow? Please enlighten me!

Analysis:

According to the structure, control valves are divided into nine categories: (1) single-seat control valves; (2) Two-seat control valve; (3) sleeve regulating valve; (4) Angle control valve; (5) Three-way regulating valve; (6) diaphragm valve; (7) butterfly valve; (8) ball valve; (9) Eccentric rotary valve. The first six strokes are straight strokes, and the last three are angular strokes.

These nine products are also the most basic products, also known as ordinary products, basic products or standard products. All kinds of special products and special products are improved and modified on the basis of these nine types of products.

You don't need to read the following contents for your reference:

According to the structural characteristics, control valves can be roughly divided into the following nine categories:

(1) Straight-through single-seat control valve: This valve is the most widely used, but there are some leaks. Allowable pressure difference? The flow path is complex and the structure is simple, which is suitable for clean media occasions with strict leakage requirements and small working pressure difference, but small-caliber valves (nominal diameter DN < 20 mm) can also be used for occasions with large pressure difference. When using, attention should be paid to proofreading the allowable pressure difference to prevent the valve from closing.

(2) Straight-through double-seat control valve: Contrary to the straight-through single-seat control valve, it has the characteristics of large leakage and large allowable pressure difference, and is suitable for clean media occasions with lax leakage requirements and large working pressure difference. When selecting a valve, we should pay attention to whether the leakage of the valve meets the requirements of process control.

(3) Sleeve valve: Sleeve valve is divided into two structures: single seal and double seal. The former is similar to a single-seat valve and is suitable for single-seat valve occasions. The latter is similar to a two-seat valve and is suitable for the occasion of a two-seat valve. Sleeve valve also has the characteristics of good stability and convenient disassembly, but its price is 50% ~ 200% higher than that of single-seat valve and double-seat valve, and it needs special winding gasket. Sleeve valve is the most widely used valve after single-seat valve and double-seat valve.

(4) Angle valve: the throttling form is equivalent to a single-seat valve, but the flow path of the valve body is simple, which is suitable for leakage requirements. Clean medium occasions with small pressure difference and occasions requiring right-angle pipes.

(5) Three-way valve: It has three channels, which can replace two straight-through single-seat valves. It is used in the occasions of split flow, combined flow and two-phase flow, and the temperature difference is not more than 150℃. When DN≤80 mm, the confluence valve can be used for shunting occasions.

(6) Diaphragm valve: The flow path is simple, and the diaphragm has certain corrosion resistance, which is suitable for two-position cut-off of unclean medium and weakly corrosive medium.

(7) Butterfly valve: It is equivalent to taking a straight pipe section as the valve body, and the valve body is equivalent to the valve seat, so the "self-cleaning" performance is better and bigger? Light weight. Suitable for dirty media and occasions with large caliber, large flow and large pressure difference. When DN > 300 mm, it is usually done by butterfly valve.

(8) Ball valve: The "O" ball valve is an unobstructed valve in the fully open state, and its "self-cleaning" performance is the best, which is suitable for two-position cut-off occasions with particularly unclean and fibrous media. V-ball valve has approximately equal percentage adjustment characteristics, and is suitable for control occasions with dirty and fibrous media and large adjustable ratio. Ball valves are more expensive.

(9) Eccentric rotary valve: This valve is located between the butterfly valve and the ball valve. It has good "self-cleaning" performance, good regulation performance, and can also be cut off. It is suitable for regulating occasions with unclean media and small leakage requirements, but the price of this valve is relatively expensive.

? Among these nine products, the first six are straight stroke control valves and the last three are angular stroke control valves. As users of control valves, we must understand their characteristics and precautions. All kinds of variant products and improved products are evolved from these nine categories of products, and it is easy to master the application of other products by understanding these nine categories of products.