The lining material for the lined valve

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Lined valve, is a type of fluorine plastic lined corrosion-resistant valve, which lined fluorine resin (or by special processing) in steel or iron valve pressure bearing inner wall or the surface of inner parts bt the molding or injection process for strong corrosion medium. Simply put, the lining material needs to be filled in the valve body where the medium can reach. Fluorine lined valves can be used in all concentrations of sulfuric acid, hydrochloric acid, hydrofluoric acid, aqua regia and various organic acids, strong acids, strong oxidants, and other solid media, but is limited to temperature (for medium-range form -50℃to150℃). The valves that can be manufactured with lined plastic include lined butterfly valves, lined ball valves, lined globe valves, lined plug valves, lined gate valves, lined cock valves, etc. There are many fluorinated materials that can be used for lining valves. The most commonly used materials are FEP (F46) and PCTFE (F3). Today, we will introduce the characteristics and applications of these materials for you, if interested in, please read on!

 

Materials Working temperature Working conditions Features
PTFE（F4） -180～200℃ Strong acid, base,  oxidant, etc Excellent chemical stability and corrosion resistance, good electrical insulation, heat resistance, self-lubricity;

Corroded by molten alkali metal, low friction coefficient, but poor fluidity, large thermal expansion, need sintering molding instead injection molding.
PVC 0～55℃ Resistant to water, alkali, non – oxidizing acid, chain hydrocarbon, oil and ozone High mechanical strength, excellent chemical stability and electrical conductivity, good aging resistance, easy fusion and bonding, low price.
FEP（F46） -85～150℃ Any organic solvents or reagents, dilute or concentrated inorganic acids, bases, ketones, aromatics, chlorinated hydrocarbons, etc.; The mechanical and electrical properties and chemical stability are basically similar to F4, but with high dynamic strike toughness and excellent weather resistance and radiation.
PCTEF(F3) -195～120℃ Various organic solvents, inorganic corrosion fluids (oxidizing acids) The heat resistance, electrical property and chemical stability are next to F4, and the mechanical strength, creep property and hardness are better than F4.
PVDF（F2） -70～100℃ Most chemicals and solvents Good toughness, easy to form. Tensile strength and compression strength are better than F4 and can withstand bending, radiation, light and aging, etc
RPP -14～80℃ An aqueous solution of inorganic salts, dilute or a concentrated solution of an inorganic acid/base; One of the lightest plastics. Its yield, tensile and compressive strength and hardness are better than those of low-pressure polyethylene.

Good heat resistance, easy to form, cheap price. It’s dynamic impact, fluidity and bending elastic modulus are improved after modification, .
PO -58～80℃ Various concentrations of acid, alkali salts and some organic solvents; The most ideal anticorrosive material has been widely used in rotary forming large equipment and pipelining.

 

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What’s the Eccentric semi-ball valve used for?

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The eccentric semi-ball valve is consist of the valve body, eccentric shaft, valve cover, semi-ball, bushings, valve seat, and other parts, it rotates the eccentric shaft by 90 °to open/close the valve to cut off the medium, suitable for sewage disposal, petroleum, chemical, electricity and paper industries processing of slurry, slurry ash, paper pulp, alumina and other sealing tightness occasions, especially in two-phase flow medium. According to its installation structure, the eccentric semi-ball valve can be divided into a top entry eccentric semi-ball valve and side entry eccentric semi-ball valve.

The design of the eccentric ensures no friction between the valve seat and semi-ball during opening or closing, extending the valve serving life. There is a certain eccentricity between the rotation of the eccentric axis and the center of the valve body, that is, the half-ball changes the axial displacement with the change of angular displacement when it is opened and closed so that they are in a linear proportional relationship, and its motion path is a semi-parabolic trajectory. The trajectory of the hemispheric body from the lowest point to the highest point automatically wedges the seat, and the seat also automatically generates a preload depending on the elastic modulus of the material to close tightly.

Eccentric semi ball valve provides many advantages like, simple structure, lightweight, small resistance and torque, tight sealing, easy online maintenance, just open the valve cover and take out the eccentric shaft. The semicircular port has good flow performance and linear regulation performance, and impurities will not be deposited in the valve body cavity. In addition, she has the function of cutting, that is, in the closing of the media can be cut off debris, to ensure the normal opening and closing of the valve. The semi-ball and seat of the valve can be surfacing with different alloys to meet the needs of different occasions.

 

Design and manufacture: MSS SP-108

Size: DN2″-40″

PN: CLASS150-CLASS900

 

Materials

Part Material
Valve body WCB、A105
Shaft 420、410
Disc Nitriding steel, wear-resistant steel
Seat Nitriding steel, wear-resistant steel
Bearing Aluminum – bronze
Packing PTFE、Flexible graphite

 

Specifications

PN（Mpa） 0.6 1.0 1.6 2.5 4.0
DN（mm） 40-600 40-600 40-600 40-600 40-600
Sealing test pressure（Mpa） 0.66 1.1 1.76 2.75 4.4
Body test pressure（Mpa） 0.9 1.5 2.4 3.75 6.0
Working temperature（℃） －29～300、－29～425、－29～540
Medium Liquids like seawater, sewage, acid and alkali or slurry, steam, gas, oil, mud, ash etc.
Operation Handwheel, electric, pneumatic
Connection Flanged, wafer
Installation Vertical and horizontal

 

Size

PN(MPa) DN(mm) Size (mm)
d1 L D D1 D2 D6 f f2 b Z-φd H1 H2
1.6 25 25 150 115 85 65 – 2 – 14 44 – 75
32 32 165 135 100 78 – 2 – 16 48 – 105
40 40 180 145 110 85 – 3 – 16 48 – 95
50 50 200 160 125 100 – 3 – 16 48 – 107
65 65 220 180 145 120 – 3 – 18 48 – 142
80 80 250 195 160 135 – 3 – 20 88 – 152
100 100 280 215 180 155 – 3 – 20 88 – 178
125 125 320 245 210 185 – 3 – 22 88 – 252
150 150 360 280 240 210 – 3 – 24 8-23 – 272
200 200 400 335 295 265 – 3 – 26 12-23 – 342
2.5 25 25 150 115 85 65 – 2 – 16 44 – 75
32 32 165 135 100 78 – 2 – 18 48 – 85
40 40 180 145 110 85 – 3 – 18 48 – 95
50 50 200 160 125 100 – 3 – 20 48 – 107
65 65 220 180 145 120 – 3 – 22 88 – 142
80 80 250 195 160 135 – 3 – 24 88 – 152
100 100 280 230 190 160 – 3 – 28 8-23 – 178
125 125 320 270 220 188 – 3 – 30 8-25 – 252
150 150 360 300 250 218 – 3 – 34 8-25 – 272
200 200 400 360 310 278 – 3 – 34 12-25 – 342
4.0 25 25 150 115 85 65 58 2 4 16 44 – 75
32 32 180 135 100 78 66 2 4 18 48 – 107
40 40 200 145 110 85 76 3 4 18 48 – 95
50 50 220 160 125 100 88 3 4 20 48 – 107
65 65 250 180 145 120 110 3 4 22 88 – 142
80 80 280 195 160 135 121 3 4 22 88 – 152
100 100 320 230 190 160 150 3 4.5 24 8-23 – 178
125 125 400 270 220 188 176 3 4.5 28 8-25 – 252
150 150 400 300 250 218 204 3 4.5 30 8-25 – 272
200 200 502 375 320 282 260 3 4.5 38 12-30 – 342

 

What’s dome valve?

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In the field of power, metallurgy, chemical, food, pharmaceutical and other industries, there are often need to transfer high-temperature particles or powder raw materials to the specified container, where a quick cut-off valve, dome valve is needed can be used here to cut off the medium and obtained sealing.

It can cut off the flowing material into the pressure tank or close to achieve sealing so as to ensure the filling rate of the pressure tank is 100% without a material level gauge, safe and reliable. The inflatable pressure sealing ring embedded in the dome seat ensures the working pressure difference between upstream and downstream of the valve and avoids the abrasion of the sealing ring. The dome valve is mainly operated by pneumatic actuators, the linear cylinder or sector cylinder is fully closed driven, which offers a large output torque. When the valve is opened and closed, there is no contact between the valve core and the inflatable rubber sealing ring, reliable sealing performance and can work under severe working conditions.

Working principle:

The ball valve is opened/closed with a gap of about 2mm between the spool and the rubber seal ring, allowing them to move in a contactless manner without causing or reducing wear. Fully sealed straight or sector cylinder drives the dome valve to rotate, effectively preventing dust caused by wear, leakage, etc. When the dome valve is closed, the rubber seal ring inflates, expands, and presses tightly against the spherical dome spool, forming a reliable seal ring band that prevents material flow.

Features of the dome valve:

1. Lightweight, fast action, switch only 5~8 seconds, valve drive pneumatic, is the ideal part in the pipeline automation system;

2. The ball has no friction with the sealing ring in the whole process of opening and closing, which improves the service life of the valve to a limited extent;

3. Upper and lower stem bushings are self-lubricating, with small friction coefficient, flexible opening and closing, and reliable sealing performance;

4. The valve switch signal device can realize remote automatic control. Integrated and quick connector for easy operation.

 

Specifications:

DN, mm 50 80 100 150 200 250 300
Working pressure, MPa ≤1.0
Working temperature ℃ ≤200
Air source Pressure, MPa 0.4～0.6
Gas consumption, L/time 1～3
Medium Granule, dry ash, dry powder materials, etc
Material Valve body: WCB;

Doom: WCB+Chromeplate/Ni60

Seat: Butyl rubber/Viton

Stem/bonnet/York: A105

Cylinder: Aluminum alloy

Notes: The filling pressure of the rubber sealing ring should be 0.30 ~ 0.60MPa and higher than the conveying pressure 0.15MPa, the working pressure of the cylinder should be 0.45 ~ 0.65MPa, and the compressed air should be clean, dry and oil-free.