Introduction to the

New the characteristics of the high life stainless steel butterfly valve and butterfly valve in use process problems

The telescopic butterfly valve as a kind of used to implement the on-off and flow control components, piping system in petroleum, chemical industry, metallurgy, water and electricity and so on many

The extremely widespread application in the field. In butterfly valve technology has been known, its seal form with seal structure, sealing materials for rubber, ptfe, etc. Because of the limitation of structural features is not adapt to the high temperature, high pressure and corrosion resistance, wear resistance, etc. Existing a more advanced butterfly valve is a triple eccentric metal hard seal butterfly valve, the valve body and seat for the Siamese components, valve seat sealing surface layer welding temperature resistant, corrosion resistant alloy material. Multilayer soft fold type sealing ring is fixed on the valve plate, the butterfly valve and the traditional butterfly valve compared with high temperature resistant, convenient operation, opening and closing without friction, closed as the actuator torque increases to compensate for sealing, improve the butterfly valve sealing performance and prolong the service life of the advantages.

Working principle of the 2

Telescopic butterfly valve is a standard valves by tianjin independent design, development, manufacture of a product, is made open-close circular disc and stem rotation to open

Opening and closing and regulating fluid channel of a valve. The telescopic butterfly butterfly plate installed on the diameter of the pipe direction. In telescopic cylindrical channels in butterfly valve body, disc disc around the axis of rotation, rotation Angle for 0 ° ~ 90 °, rotate to 90 °, the valve is fully open.

Three structural characteristics

Telescopic butterfly valve has simple structure, small volume, light weight, material consumption province, small installation size, small quick, 90 ° reciprocating rotary switch, low driving torque, etc, used for truncation, connected, regulate medium in pipe has good flow control characteristics and close the sealing performance. Telescopic butterfly valve in the fully open position, the thickness of the telescopic butterfly valve is the only resistance when the medium flows through the body, so by the valve pressure drop is small, it has good flow control characteristics. Telescopic butterfly valve with elastic seal and metal seal two kinds of seal type. Elastic sealing valve, sealing ring can be embedded in the body or attached to the butterfly plate peripheral.

Telescopic butterfly valves with metal sealing valve generally live longer than elastic sealing valve, but it is hard to be completely sealed. Metal sealing can adapt high working temperature, elastic seal has the defect of being limited by the temperature. If required telescopic butterfly valve used as flow control, mainly is the right choice of the size and type of valve. Telescopic structure of butterfly valve is especially suitable for production of large diameter valves. Telescopic butterfly valve not only in the oil, gas, chemical industry, water treatment and other general industrial used widely, but also applied to the cooling water system of thermal power plants.

Commonly used telescopic butterfly valve has the wafer butterfly valve, flanged butterfly valves, butt welding type 3 kinds. The wafer butterfly valve with stud connecting the valve in place between two pipe flanges; Flanged butterfly valve is a valve with flange, bolts on the valve flange connection on the pipe flange on both ends; Two end connected to the pipe welding butt welding type butterfly valve. Butterfly plate streamline design, make the loss of the fluid resistance is small, is a kind of energy-saving products. Stem for stem structure, through conditioning processing, has the good comprehensive mechanical properties and corrosion resistance, abrasion resistance. When the butterfly valve opening and closing the valve stem make rotation movement up and down and run, not only the valve stem packing is not easy to damage, reliable sealing. With the butterfly plate fixed cone pin, overhanging end to prevent rushed out of the design, in order to avoid in the stem and disc joint stem collapse accident broke out.

1, small and light, easy disassembling and maintenance, and can be installed in any position.

2, simple and compact structure, small operation torque, 90 - degree rotating open quickly.

3, flow characteristic is straight line. Excellent regulation performance.

4, be used between the butterfly plate and the valve stem structure without pin, overcome the possible leak point.

5, seal can be replaced, and reliable sealing achieve two-way sealing.

6, the butterfly plate can spray coating according to user requirements, such as nylon or ptfe.

7, the valve can be designed as flange connection and connection to the clamp.

Eight, can choose manual, electric or pneumatic drive way.

4 points for attention

1, the assembly check pneumatic butterfly valve before no missing parts, each part model is correct, check valve body without sundry, non-blocking solenoid valve and the muffler

2, the valve and cylinder are placed in the closed position.

3, will hit the valve cylinder, (installation direction parallel to the valve body or vertical), to see whether the screw holes for is, does not have the too big deviation, if there is a little deviation, cylinder block turning point, then tighten the screw.

Pneumatic butterfly valve, 4, after the installation of debugging (normally gas supply pressure is 0.4 ~ 0.6 MPa), debug runtime must be manually solenoid valve open/close (the solenoid valve coil manual operation shall be effective after losing electricity, observe the telescopic butterfly valve opening and closing. If in the process of debugging operation found some difficulty in opening and closing process of the initial valve, after normal, you need the cylinder stroke down (on both ends of the cylinder stroke adjusting screw to adjust a bit at the same time, adjust the need to run the valve in the open position, and then dispatch air off again), until the valve opening and closing action smooth and closed without any leakage. Also it is important to note that the adjustable type silencer can adjust the valve opening and closing speed, but not too small, otherwise may cause the valve is not action.

5, have to send before installation should keep dry, not in open air

6, the butterfly valve to check the pipeline before installation, make sure that the pipe welding slag and other foreign body

7, telescopic butterfly valve body resistance is moderate, hand-operated butterfly valve torque matching with the selected actuator torque.

8, telescopic butterfly valve connected with the flange specifications correctly, pipe flanges are in conformity with standard butterfly valve flange to the clamp. It is recommended to use special butterfly valve flange, flat welding flange shall be used.

9, confirm the flange welding is correct, not welding flange butterfly valve after the installation, so as not to burn rubber parts.

10 and the pipe flange are going to have to pack good, and with butterfly valve in the.

11 and install all flange bolts, with the hand tight, just, will confirm the butterfly valve with flange and with the opening and closing butterfly valve, to ensure that the opening and closing flexible.

12, the valve fully open, tighten bolts, using a wrench, in accordance with the diagonal order without washers, never will bolt screw tight, in case caused serious deformation, valve ring opening and closing torque is too big.

Use 5 items

One, due to multi-layer soft fold type sealing ring fixed in the valve plate, when the valve plate normally open state media on the sealing surface to form positive scour, soft sealing strip of metal sandwich after flushing, directly affect the sealing performance.

Second, restricted by structure condition of the structure does not adapt to do below path DN200 valves, because the valve plate structure is too thick, large flow resistance.

Third, because of the principle of triple eccentric structure, between the sealing surface of valve plate and valve seat sealing is to rely on the drive torque valve plate pressure to the valve seat. Is flow state, the higher the medium pressure seal compression tight. When the countercurrent flow medium with the increase of medium pressure valve plate and valve seat unit is less than the pressure medium, the positive pressure between seal began to leak.

High performance soft sealing butterfly valve,

It has the following characteristics: the seat sealing by soft t-shaped sealing ring on both sides of the multi-layer pieces of stainless steel.

Valve plate and valve seat sealing surface for the oblique cone structure, the valve plate oblique cone surface welding heat resistance, corrosion resistant alloy material; Fixed between the adjusting ring clamp spring together with the clamp on adjusting bolt assembly structure. This structure can effectively compensate the tolerance zone between sleeve and body and the elastic deformation of the stem under medium pressure, solve the valves in the process of the two-way exchange medium conveying the sealing problems.

Soft T on both sides of the multi-layer stainless steel pieces of sealing ring, with metal sealing and soft sealing the dual advantages of under low temperature and high temperature circumstances, all with zero leakage sealing performance. Trials show that pool is flow state (medium flow direction is same as the rotation direction of the butterfly plate), the sealing surface pressure is the drive torque and the medium pressure in the valve plate. Positive medium pressure valve plate oblique cone surface and valve seat sealing surface squeezed more tightly, sealing effect is better.

When the current state, between the valve plate and valve seat sealing pressure on drive torque make the valve plate to the seat. As the reverse medium pressure increases, the unit is pressure between the valve plate and valve seat is less than the pressure of medium, the adjusting ring after the loading of the spring deformation energy stored by compensating valve plate and valve seat sealing surface of the tight pressure automatic compensation effect.

So the utility model is not like the existing technology, soft hard multi-layer sealing ring, installed in the valve plate directly installed on the valve body, in the middle of the plate and seat add adjustable ring is the ideal way of two-way hard seal. It will replace gate, and the spherical valve

6 classification

According to the classification of structure form

(1) the center seal butterfly valve

(2) single eccentric valve seal coal

(3) double eccentric butterfly valve seal

(4) triple eccentric butterfly valve seal

According to the sealing surface texture classification

(1) soft sealing butterfly valve.

1) seal made of nonmetal soft materials of nonmetal soft materials.

2) seal hard material from metal to non-metal of soft materials.

(2) the metal hard seal butterfly valve. Seal hard material from metal to metal hard material.

According to the seal form classification

(1) the forced sealing butterfly valve

1) elastic sealing butterfly valve. Sealing pressure by closing valve plate extrusion valve seat, valve seat or valve plate elasticity

2) plus torque seal butterfly valve. Sealing pressure produced by plus on the valve shaft torque

(2) pressurized sealing butterfly valve. Sealing pressure by seat or play a seal on the valve plate element pressurized

(3) automatic sealing butterfly valve. Sealing pressure produced by medium pressure automatically.

According to the working pressure

(1) the vacuum butterfly valve. Working pressure is lower than the atmosphere of butterfly valve.

(2) low pressure butterfly valve. Nominal pressure PN < 1.6 MPa butterfly valve.

(3) the intermediate pressure butterfly valve. Nominal pressure PN 2.5-6.4 MPa butterfly valve.

(4) high pressure butterfly valves. Nominal pressure PN to 10. 0-80.0 MPa butterfly valve.

(5) the ultrahigh pressure butterfly valve. Nominal pressure PN > 100 mpa butterfly valve.

According to working temperature

(1) high temperature butterfly valve. T > 450 C of the butterfly valve

(2) medium temperature butterfly valves. 120 C < t < 450 C of the butterfly valve

(3) the normal temperature butterfly valves. A 40 c < t <; 120 C of the butterfly valve

(4) cryogenic butterfly valve. A 100 < t < 40 C butterfly valve

(E) cryogenic butterfly valve. T < 100 C of the butterfly valve

According to the connection mode classification

(1) butterfly valve to the clamp

(2) the flange butterfly valve

(3) a lug butterfly valve

(4) the welding type butterfly valve

7 main parts material

Parts name material

The body cast iron, cast steel, stainless steel, chrome molybdenum steel, alloy steel

Butterfly plate cast steel, alloy steel, stainless steel, chrome molybdenum steel

Seal rubber, ptfe, the polyester, stainless steel

Stem 2 cr13, stainless steel, chrome molybdenum steel

Telescopic pipe cast iron, cast steel, stainless steel, chrome molybdenum steel

Flexible graphite packing