RUBBER LINED BUTTERFLY · PDF fileCOMPANY PROFILE C.V.B. valvole industriali S.r.l. is an...

RUBBER LINED BUTTERFLY VALVES RUBBER LINED BUTTERFLY VALVES RUBBER LINED BUTTERFLY VALVES

C.V.B. Valvole Industriali s.r.l.

COMPANYCOMPANYCOMPANY PROFILEPROFILEPROFILE

C.V.B. valvole industriali S.r.l. is an Italian leading manufacturing company located at 25 Km. north of

Milan and established in 2004 to provide top quality metal to metal triple offsets torque seated quarter

turn valve solution to the Oil and Gas Market. Although their relatively newly built story as Company

they can present a thirty year experience in the Valve Market due to both their management and em-

ployees consolidated presence either in the Industrial and Petrochemical Valve Markets. During these

years C.V.B. s.r.l. have performed a constant growth business wise and size wise following the increased

demand for a vast range of products and solutions so far.

Product wise C.V.B. s.r.l. went through an internal re-organization with different product lines in such a

way it would be possible to serve the Market with specific products and services.

Presently the Product Range consist of:

• Triple eccentric metal to metal torque seated quarter turn valve ANSI standard from 3 up to 48” ,

from 150 up to 900 pressure class– Materials: WCB, LCB, LCC, WCC, WC6, WC9, CF8,

CF8M,CF3M,Titanium- Others according to ASTM Standard- Double Flanged, Lug, Wafer, Butt Wel-

ded Type

• Triple eccentric metal to metal torque seated quarter turn valve DIN from 80 up to 1400 diame-

ter, from PN 10 up to PN 80 pressure class- Materials: Carbon steel: 1.0460-1.0619,Stainless Steel:

1.4581-1.4552, Alloy Steel: 1.7363-1.7365

• Double eccentric H.P. Valve -Soft Seated, Fire Safe Seat, Metal Seated ANSI standard from 2 up

to 24”, 150,300 pressure class – Materials: WCB,CF8,CF8M, Others according to ASTM Standard – Wa-

fer and Lug Type

• Rubber lined butterfly valves -from 2” up to DN 48”, ANSI 150 and PN from 6 up 25 pressure class-

Materials:Grey and Ductile Iron, WCB, CF8M, Aluminum Bronze, Aluminum – Wafer and Lug Type

• Control Dampers for Hot Air and Fumes up to 700°C- from DN32 up to DN 1200 diameter, PN 6 up

to PN 16 pressure class- Materials: Grey and Ductile Iron, WCB,CF8M, Others according to ASTM

Standard – Double Flanged, Wafer and Lug Type

C.V.B. VALVOLE INDUSTRIALI S.R.L.

Via Industria,24 - 20020 Arconate (Mi)

Tel: (+39).0331.461737 Fax: (+39).0331.539175E-mail: [email protected]


Rubber lined butterfly valves found a wider application tanks to their well proven reliability and their advantages

compared to conventional valves.

CVB rubber lined butterfly valves, especially, find application in many dfferent industrial sectors either as shut-off

and control valves for various type of fluids. Their design can meet requirements in the iron and steel, oil and gas,

chimical, ship building, textile, food and beverage, water treatment, HVAC, etc.. Main advantages are:

• Compact size and light weight

• Elastomer seat with internal metallic support ring which ensures geometric and dimensional stability as well as

easy replacement without using tools in the event of accidental breakage.

• The rubber seat(elastomer) protects the valve body from the fluid and with the disc are the sole components

directly in contact with the fluid, therefore there is no need to use special materials for the valve body.

• The seat partially covers the valve body sides thanks to its special shape and therefore allows the installation

on the pipe line without any additional gasket.

• The disc is self-centering thanks to the floating coupling on the stem and to its lenticular shape. It rapresents

an excellent means for minimizing pressure drops across the valve.

• The accurate machining of the disc edge ensures tight shut-off with operating pressures from 10 ¯³ Torr up to

21,5 bar positive, through an appropriate interference fit with the elastomer seat.

• Rubber lined butterfly valves represent an ideal shut-off solution for operating pressures from vacuum up to

over 20 bar, while they can match operating temperatures depending on the type of elastomer material.


Via Industria ,24 - 20020 Arconate (Mi)



WAFER TYPE DN 40 WAFER TYPE DN 40 WAFER TYPE DN 40 –––DN 600DN 600DN 600 LUG TYPE DN 40 LUG TYPE DN 40 LUG TYPE DN 40———DN 600DN 600DN 600

DN A B C D E F G H H1 K L W L

40 188 90 98 41 12 33 15 145 111 6,6 31 2,2 2,6

50 205 96 109 41 12 43 15 160 120 7,2 36 2,9 3,5

65 230 108 122 41 12 46 15 180 138 12,9 53 3,9 4,9

80 250 118 132 41 12 46 15 198 150 19,3 69 4,2 5,4

100 285 132 153 41 12 52 15 230 213 27,2 90 5 7

125 327 150 177 41 16 56 15 256 243 36,4 115 7,4 10

150 359 165 194 41 16 56 15 286 267 48,6 142 8,5 11,1

200 419 194 225 41 16 60 15 348 320 69,8 199 11,8 17

250 495 220 275 41 18 68 15 414 402 90 238 18,5 27,4

300 559 262 297 41 18 78 15 490 473 111,1

289 29,8 40,4

350 632 281 351 41 d. 44,5 78 25 436 516 126 324 50 60

400 681 305,5 375,5 41 d. 44,5 102 25 483 590 138 367 70 90

450 749 349 400 41 d. 44,5 114 25 540 644 157 417 90 110

500 798 373 425 41 d. 44,5 127 25 580 715 179 468 110 150

600 936 445 491 90 d. 63 155 25 710 830 218 572 210 270

OVERALL DIMENSIONS WEIGHT Kg




DIMENSIONS AND DRILLING DIMENSIONS AND DRILLING DIMENSIONS AND DRILLING

DN K R S T Nr. T

M PN6

M PN10

M PN16

M

150

P PN6

P PN10

P PN16

P

150

40 6,6 90 70 8,5 4 100 110 110 98,5 M12 M16 M16 M14

50 7,2 90 70 8,5 4 110 125 125 120,5 M12 M16 M16 M18

65 12,9 90 70 8,5 4 130 145 145 139,5 M12 M16 M16 M18

80 19,3 90 70 8,5 4 150 160 160 152,5 M16 M16 M16 M18

100 27,2 90 70 8,5 4 170 180 180 190,5 M16 M16 M16 M18

125 36,4 90 70 8,5 4 200 210 210 216 M16 M16 M16 M20

150 48,6 90 70 8,5 4 225 240 240 241,5 M16 M20 M20 M20

200 69,8 90 70 8,5 4 280 295 295 298,5 M16 M20 M20 M20

250 90 125 102 11 4 335 350 355 362 M16 M20 M22 M22

300 111,1

125 102 11 4 395 400 410 432 M20 M20 M22 M22

350 126 175 140 17 4 445 460 470 476 M20 M20 M22 M27

400 138 175 140 17 4 495 515 525 540 M20 M22 M27 M27

450 157 175 140 17 4 550 565 585 578 M20 M22 M27 M30

500 179 175 140 17 4 600 620 650 635 M20 M22 M30 M30

600 218 210 165 22 4 705 725 770 749,5 M22 M27 M33 M33

NrP PN6

4

4

4

4

4

8

8

8

12

12

12

16

16

20

20

NrPPN10

4

4

4

4

8

8

8

8

12

12

16

16

20

20

20

NrPPN16

4

4

4

8

8

8

8

12

12

12

16

16

20

20

20

NrP

150

4

4

4

4

8

8

8

8

12

12

12

16

16

20

20





WAFER TYPE DN 700 WAFER TYPE DN 700 WAFER TYPE DN 700 –––DN 1000DN 1000DN 1000 LUG TYPE DN 700 LUG TYPE DN 700 LUG TYPE DN 700———DN 1000DN 1000DN 1000

OVERALL DIMENSIONS WEIGHT Kg

DN A B C D E F G H H1 K L W L

600 936 445 491 90 d. 63 155 25 710 830 218 572 210 270

700 1126 544 582 100 d.65/80 165 27 810 900 260 665 275 378

750 1177 568 609 100/120 d.80/95 190 31 915 985 278 720 333 440

800 1229 602 627 100/120 d.80/95 190 31 950 1020 305 775 377 491

900 1349 663 686 100/120 d.80/95 203 31 1090 1160 340 859 469 553

1000 1492 728 764 120/135 d95/110 216 31 1170 1240 385 959 610 694




DIMENSIONS AND DRILLING DIMENSIONS AND DRILLING DIMENSIONS AND DRILLING

DN K R S T Nr. T

M PN6

M PN10

M PN16

M

150

P PN6

P PN10

P PN16

P

150

NrP PN6

NrPPN10

NrPPN16

NrP

150

600 218 210 165 22 4 705 725 770 749,5 M22 M27 M33 M33 20 20 20 20

700 260 300 254 17 8 810 840 840 850 M22 M27 M33 M33 24 24 24 28

750 278 300-

/350

254-

/298

17/21 8 - - - 914,4 - - - M33 - - - 28

800 305 300-

/350

254-

/298

17/21 8 920 950 950 978 M27 M30 M36 M39 24 24 24 28

900 340 300-

/350

254-

/298

17/21 8 1020 1050 1050 1086 M27 M30 M36 M39 28 28 28 32

1000 385 350-

/415

298-

/356

21/32 8 1120 1160 1170 1200 M27 M30 M39 M39 28 28 28 36

For flange ANSI 150 thread according to ANSI B1.2 Type UNC– Upon request UNI 5870/71





MATERIALS MATERIALS MATERIALS

BODY DISC STEM SEAT

Grey Iron G.25 ASTM A 48-40B Grey Iron G.25 ASTM A 48-40B Stainless Steel ASTM A479-F316 Buna

Ductile Iron GS ASTM A 536 Ductile Iron GS ASTM A 536 Stainless Steel ASTM A479-F316L EPDM-EPDM H.T

Carbon Steel ASTM A216 WCB Carbon Steel ASTM A216 WCB Stainless Steel ASTM A582-A 416 Neoprene ASTM D 2000

Stainless Steel ASTM A351-CF8M Carbon Steel ASTM A 105 (17-4-PH) ASTM A564-type 630 Viton

Stainless Steel ASTM A351-CF3M Stainless Steel ASTM A315-CF8M Hastelloy C– 276 ASTM B 574-94 Hypalon

Aluminum ASTM B 275 Stainless Steel ASTM A182-F316 Monek K500 –BS 3076 NA Silicon

Aluminum Bronze ASTM B 148 Aluminum Bronze ASTM B 148 Titanium ASTM B 348 Cr. 5 Teflon -PTFE ASTM D 1437-73

Hastelloy C– 276 ASTM A 484 Natural Rubber

Titanium ASTM B 348 Cr. 5

Rubber coated/EPDM,Buna,etc.

Powder coated/Rilsan,Halar,etc.





GEAR AND MANUAL GEAR AND MANUAL GEAR AND MANUAL OPERATORSOPERATORSOPERATORS

DN A B C D F H W

40 188 333 167 40 214 145 313

50 205 350 167 40 214 160 313

65 230 375 167 40 214 180 313

80 250 395 167 40 214 198 313

100 285 430 167 40 214 230 313

125 327 472 167 40 214 256 313

150 359 504 167 40 214 286 313

200 419 564 167 40 214 348 313

250 495 640 167 40 214 414 407

300 559 704 167 40 214 490 407

350 - 827 247 - 343 436 -

400 - 876 247 - 343 483 -

450 - 944 247 - 343 540 -

500 - 993 247 - 343 580 -

600 - 1343 310 - 492 710 -





PNEUMATIC DOUBLE EFFECT AND SPRING RETURN PNEUMATIC DOUBLE EFFECT AND SPRING RETURN PNEUMATIC DOUBLE EFFECT AND SPRING RETURN

Diameter mm.

Diameter inch.

Model double effect

A mm.

B mm.

C mm.

40 1 1/2 351 150 81

50 2 351 150 81

65 2 1/2 410 204 92

80 3 430 204 92

100 4 475 230 102

125 5 532 271 113

150 6 591 305 133

200 8 664 360 140

250 10 781 380 160

300 12 869 462 175

350 14 942 462 175

400 16 1081 555 215

450-600 18-24 Upon Request - - -

Model Spring return

Upon Request

A mm.

-

385

435

455

517

572

645

729

895

959

1032

1081

-

B mm.

-

204

271

271

305

360

380

462

555

555

555

555

-

C mm.

-

92

113

113

133

140

160

175

215

215

215

215

-





DYNAMIC TORQUE IN DYNAMIC TORQUE IN DYNAMIC TORQUE IN NNNmmm

Diameter mm.

40 50 65 80 100 125 150 200 250 300 350 400 450 500 600

Diameter 1 1/2 2 2 1/2 3 4 5 6 8 10 12 14 16 18 20 24

DP 3,5 bar 8 10 12 22 30 38 64 115 205 260 420 555 960 1250 2300

DP 10,5 bar 10 15 22 35 70 95 128 195 280 400 895 1185 1450 1800 3460

DP 17,5 bar 15 25 37 58 120 160 215 330 475 685 1520 2020 2480 3060 5765

Recommended Max. Torque Values to be applied to overcome disc and seat friction due to the interference and

flow dynamic forces through the valve which tend to open and close the disc related to different pressure drops.

FLOW COEFFICIENT FLOW COEFFICIENT FLOW COEFFICIENT CVCVCV

mm. 40 50 65 80 100 125 150 200 250 300 350 400 450 500 600

inch 1 1/2 2 2 1/2 3 4 5 6 8 10 12 14 16 18 20 24

90° 80 130 200 300 550 1125 1950 3250 5000 7500 10000 12500 17500 22000 28000

80° 70 105 160 240 475 1000 1650 2725 4300 6050 8100 10800 14000 17500 24000

75° 55 90 130 205 400 830 1350 2200 3600 5000 6700 9000 12000 15000 20500

70° 45 70 105 160 305 625 1030 1750 2750 4050 5100 6500 9200 11500 16500

60° 26 53 83 125 235 490 800 1300 2150 3100 4100 5100 7100 8700 11750

50° 18 27 42 63 120 250 410 700 1150 1600 2200 2650 3700 4600 6100

40° 11 17 26 38 73 155 250 420 670 1000 1300 1700 2300 2800 3800

30° 5 9 15 22 42 88 145 250 390 550 750 900 1250 1600 2200

25° 3 6 10 15 28 60 98 170 260 380 500 650 900 1125 1500

CV = Water flow rate in gallons US per minute passing through the valve creating 1 psi pressure drop at 68 °F.

temperature. In metric unit KV= flow rate in m3/h, pressure drop 1 bar, temperature 20 ° C.

The relation between the two coefficients is CV= 1,16 KV





STEAM

Q = Flow rate Kg/h = Differential pressure outlet-inlet Kg/cm2

P = Absolute inlet pressure Kg/cm2

Q = Flow rate Kg/h = Differential pressure outlet-inlet Kg/cm2

P = Absolute inlet pressure Kg/cm2

FLOW FLOW FLOW COELLICIENTCOELLICIENTCOELLICIENT CVCVCV

Valve sizing calculation CV CV, imperial units ( CV= Flow rate GPM with 1 psi pressure drop ) allow to set the valve Nominal Diameter

depending on the fluid working condition .

Once the CV has been calculated , select the correct valve diameter by using the relevant CV valve data sheet in

order to have the calculated CV at almost 80 % of the relevant CV valve data.

Case 1° = Absolute outlet pressure greater than 50 % of the absolute inlet pressure.

Case 2° = Absolute outlet pressure equal or lower than 50 % of the absolute inlet pressure.

Corrective factor for superheated steam f Whit superheated steam, multiply the calculated CV by

corrective factor ( f ) shown on the leftside, according

to the superheat temperature ( difference between the

steam temperature at the valve inlet and the saturated

steam temperature at the inlet pressure )





FLOW COEFFICIENT FLOW COEFFICIENT FLOW COEFFICIENT CVCVCV

LIQUIDS

Q = Flow rate m3/h = Differential pressure outlet-inlet Kg/cm2

d = Density - ( water = 1 ) Kg/dm3

GAS

Q = Flow rate m3/h = Differential pressure outlet-inlet Kg/cm2

P1 = Absolute inlet pressure Kg/cm2 P2 = Absolute outlet pressure Kg/cm2 T = Absolute temperature ( t + 273) ° C

d = Gas density related to air Kg/dm3

Q = Portata gas m3/h

= Differential pressure outlet-inlet Kg/cm2

P1 = Absolute inlet pressure Kg/cm2 P2 = Absolute outlet pressure Kg/cm2 T = Absolute temperature ( t + 273) ° C

d = Gas density related to air Kg/dm3

Corrective factor for viscous liquids f For viscous liquids multiply calculated CV values by the

corrective factors ( f ) shown on the leftside, according

to the liquid viscosity , expressed in degrees Engler °E.

Note: When the liquid temperature is close to the its

saturation temperature, the fluid follows different fisical

rules.

Case 1° = Absolute outlet pressure greater than 50 % of the absolute inlet pressure.

Case 2° = Absolute outlet pressure equal or lower than 50 % of the absolute inlet pressure.





ELASTOMER ELASTOMER ELASTOMER COMPATIBILITÀCOMPATIBILITÀCOMPATIBILITÀ WITHWITHWITH FLUIDSFLUIDSFLUIDS

Ther above table should considered as a guide. Many factors can influence corrosion extent ( such : type of solution,

Concentration, temperature, impurities, etc. ). It is up to the Customer to make the final assessment depending on

the application and equipment characteristics .

Commercial Name

Technical Designation

General Application

Temperature Range

Not Recom-mended

For:

BUNA N ( NBR )

Copolymer of butadiene and high acrylonitrile

Hydrocarbons with less than 40% of aromat-ics,natural gas, air, water, sea water, brine, alcohols and glycols

- 20 °C -4 °F +100°C +212°F

SOLVENTS BENZENE XYLENE

EPDM ( EP ) EPDM H.T. ( EP H.T. )

Terpolymer of ethylene and Propylene

Water,seawater,steam,brine,abrasives, phosphate,esters, ketones,alkali,food compounds,dilute inorganic

- 35 °C -31°F +120°C +248°F - 35 °C -31°F +150°C +302°F

HYDROCAR-BONS OILS FATS DRY AIR

HYPALON ( CSM )

Chlorosufonated polyethylene

Oxidizing acids, chromic acid, sulphur based acids, hydrofluoric acid, ozone

- 18 °C 0 °F +100°C +212°F

STEAM KETONES HOT AIR NITRIC ACID

SILICONE ( VMQ )

Methylvynil silicone

Food and beverage - 30 °C -22 °F

+150°C +302°F HYDROCAR-BONS SOLVENTS STEAM

VITON ( FKM )

Copolymer hexafluoropropyl Vinylidene fluoride

Hydrocarbons with high concentration of aromatic, mineral and halogenated acids, phosphoric acid, aliphatic and aromatic ethers

- 10 °C -14°F +160°C +320°F

STEAM KETONES AMINES ESTERS ALKALI

NEOPRENE ( CR )

Polychloroprene

Oils, diluted mineral acids, alkali, fats - 18 °C 0°F

+ 90°C +194°F

KETONES CON-CENTR.ACIDS SOLVENTS

NATURAL RUBBER ( NR )

Latex ( Vegetable )

Abrasive products - 35 °C - 31°F + 65°C +149°F STEAM

HYDROCAR-BONS OILS

TEFLON ( PTFE )

Polytetrafluoro ethylene

Corrosive products, Solvents, Food and beverage - 40 °C - 40°F

+150°C +356°F ABRASIVE PROD. FLUORINE GAS ALKALI METALS





This table rates and compares the compatibility of elastomer material with specific fluids. Note that this information

should be used as quide only.An elastomer which is compatible with a fluid may not be suitable over entire range of

its temperature capability. In general, chemical compatibility decreases with an increase in service temperature.

A+= Best Possible Selection - A= Generally Compatible – B= Marginally Compatible - C= Not recommended -

Reccomendations have to be used as general guide only. Full details regarding pressure, temperature, chemical considerations, and the mode of operation must be considered when selecting an elastomer.

ELASTOMER ELASTOMER ELASTOMER COMPATIBILITYCOMPATIBILITYCOMPATIBILITY WITHWITHWITH FLUIDSFLUIDSFLUIDS





ELASTOMER ELASTOMER ELASTOMER COMPATIBILITYCOMPATIBILITYCOMPATIBILITY WITHWITHWITH FLUIDSFLUIDSFLUIDS

This table rates and compares the compatibility of elastomer material with specific fluids. Note that this information

should be used as quide only.An elastomer which is compatible with a fluid may not be suitable over entire range of

its temperature capability. In general, chemical compatibility decreases with an increase in service temperature.

A+= Best Possible Selection - A= Generally Compatible – B= Marginally Compatible - C= Not recommended -

Reccomendations have to be used as general guide only. Full details regarding pressure, temperature, chemical considerations, and the mode of operation must be considered when selecting an elastomer.





FINAL TEST PROCEDURES FINAL TEST PROCEDURES FINAL TEST PROCEDURES

All CVB rubber lined valves are submitted to final test : hydraulic test for the valve body, hydraulic and pneumatic

for tight shut-off.

PRESSURE RATING UNI PN 2,5—PN 6 - PN 10 - PN 16

• Hydraulic test of valve body ( valve disc in open position ) at a pressure 1,5 times nominal pressure

• Hydraulic seat test tight shut-off ( valve disc in closed position ) at a pressure 1,1 times nominal pressure

• Pneumatic seat test tight shut-off ( valve disc in closed position ) at a pressure of 7 bar

ANSI 150 RATING

• Hydraulic test of valve body ( valve disc in open position ) at pressure of 28,9 bar

• Hydraulic seat test tight shut-off ( valve disc in closed position ) at pressure of 19,3 bar

• Pneumatic seat test tight shut-off ( valve disc in closed position ) at pressure of 5,6 bar

DURATION OF REQUIRED TEST PRESSURE API 598

SHELL TEST OF BODY HYDRAULIC SEAT TEST PNEUMATIC SEAT TEST

DN < 65 15 sec 15 sec. 15 sec.

DN 65 –200 80 sec. 30 sec. 30 sec.

DN > 200 180 sec. 60 sec. 60 sec.

TEST PROCEDURE ACCORDING TO DIN 3230

SHELL TEST OF BODY HYDRAULIC SEAT TEST PNEUMATIC SEAT TEST

PN 6 9 bar 7 bar 6 bar

PN 10 15 bar 11 bar 6 bar

PN 16 24 bar 17,6 bar 6 bar

PN 25 38 bar 27,5 bar 6 bar

TEST PROCEDURE FOR VACUUM SERVICE

CVB rubber lined butterfly valves can be utilized on vacuum services up to 10 ¯³ Torr. Seat leakage test must

take care of the limits due to the elastomer molecular permeability .





MAINTENANCE No maintenance and/or periodic lubrication is required. CVB rubber lined valve components can be inspected or

removed quickly using normal tools. To do so, close the valve, then remove the tie-rods or bolts from the flanges

and slip the valve off the piping. Then:

• Fully open the valve. Remove the lever system or operating mechanism fitted on the valve

• Screw out plug 11, remove seal 10.

• Lift up the top stem 2 and then the lower one 3, together with the o-ring 4.

• Force the disc 12 out from the seat 13.

• Ispect and/or replace the parts where necessary, then reassembly all items in the reverse order.

• Smearing small amounts of silicone grease inside the valve body and inside the two stems. • Lastly make sure of perfect alignment of the square end of the upper stem with the broaching on the disc.

DO NOT USE GREASE IN THE PRESENCE OF OXIGEN, HYDROGEN,CHLORINE. • Normally the valves are supplied with the disc open by a few degrees and they should be installed in the

position on the piping.

• After tightening all the tie-rods or bolts, perform a few openig and closing manoeuvres to make sure there

are no assembly faults.

SPARE PARTS The only recommended spare parts for CVB rubber lined valves are : seat on the valve body13, and the stem

O-rings 4-5.

INSTALLATION AND MAINTENANCE INSTALLATION AND MAINTENANCE INSTALLATION AND MAINTENANCE




RUBBER LINED BUTTERFLY VALVES RUBBER LINED BUTTERFLY VALVES RUBBER LINED BUTTERFLY VALVES RUBBER LINED BUTTERFLY VALVES RUBBER LINED BUTTERFLY VALVES RUBBER LINED BUTTERFLY VALVES


CVB Butterfly valves are two way by means they can be

mounted with flow on either side. For installation directly

between UNI, DIN, ASA flanges without any gaskets. Before

mounting the valve between flanges, it is advisable to apply

a silicone grease film on the outer seat surfaces in contact

with the flanges. This is to avoid seizing up with mounting

flanges and risk of tearing or breakage when disassembling.

( DO NOT USE GREASE IN PRESENCE OF OXIGEN , HYDROGEN, CHLORINE ). After placing the valve , with disc in a half open position 5….20%, Wafer type is centered

between the letter; insert the tie-rods which extend right

along the outside of the valve body. Thread the nuts on the

tie-rods and tighten them uniformly.

We recommend to followthe thigtening sequence shown on

the picture .

For the LUG type valves , bodies are fitted on the outside

with lugs having tapped or through holes coinciding with the

holes on the flanges, the installation with bolts is quicker

and easier. After assembling, it is advisable to check the

proper installation by opening and closing the valves several

times.

CVB rubber lined butterfly valves can be mounted in any

position in the piping. We recommend not to install the valve

close to elbow fittings or branches, especially upstream, in

order not to impair the hydraulic behaviour of the fluid or to

cause needless stress on the valve.

CVB rubber lined butterfly valves can be installed either

vertically and horizontally but do not install the valve with its

shaft downwards.





On the shaft top end there is a machined mark

which shows the disc position when the valve is

fitted in the pipe line. The stem, has square shape

on both ends and fit directly in the disc hence no

fastening elements are needed. This allows the disc

to float on the stem and to be self-centering inside

the seal so as to form a continous tight shut-off

line with the latter.

Thanks to the special internal profile of the contact

surface disc - seat , the reciprocal back pressures

ensure tight shut-off. Meanwhile, thanks to the

special disc shape, pressure drops and rotating

forces are reduced.

Do not proceed with flange welding on pipeline

with the valve fitted between the flanges as a sort

of spacer.

Heat will damage the seat elastomer losing valve

tightness and its functionality.

Before starting with the welding activity the valve

must be removed from the pipeline.

It will be reinstalled only when the pipeline flange

temperature will be brought down below 50 °C.





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