Foreword, Pressure containing fasteners, How to specify – Flowserve BTV 2000 Lined Butterfly Valve User Manual

Page 3

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FOREWORD

The Flowserve Corporation, Flow Control Division has

established this Installation, Operating and Maintenance

Manual to facilitate field installation, operation and repair of

BTV-2000 and BUV-2000 Series Butterfly Valves.
It is recommended that questions or concerns regard ing the

processes described in this manual be directed to Flowserve

Field Sales Representative, authorized stocking distributor

or the Flowserve Corporation, Flow Control Division.
Part numbers referenced in the following sections are

available from the Flowserve Corporation, Flow Control

Division.
Only Flowserve replacement repair parts and assembly

tooling made or designed by the Flowserve Corporation

should be used.

PREssuRE COntaining FastEnERs

Material Selection

Selecting the proper fastener material is the ultimate

responsibility of the customer because the supplier does

not typically know in what service the valves will be used

or what elements may be present in the en vironment.

Flowserve normally supplies B7 (carbon steel) for ductile

cast iron and carbon steel valves. For stain less steel and

high alloy valves, B8 (stainless steel) fasteners are supplied

as standard. All fasteners used must have a minimum yield

strength of 40,000 PSI, a minimum elongation of 12% and

be compatible with the process fluid. Determining compati-

bility to the process fluid goes beyond a material being

resistant to general corrosion because the more important

con sid eration is a material’s resistance to stress corrosion

cracking. Depending on the service, it may make sense to

use B7 fasteners on high alloy valves. One such service

would be marine environments because of stainless steel’s

susceptibility to stress corrosion cracking in chloride

environments. Another key aspect of fasteners is frequent

visual inspection. Because of the common practice of using

steel fasteners rather than stainless steel to avoid chloride

stress corrosion cracking, visual inspection is recom-

mended to monitor the general corrosion of these fasteners.

If jacketing or insulation is used on a valve, it must be

periodically removed for visual inspection of the fasteners.

If you wish assistance in determining the proper fasteners

to use, please refer to the attached chart or contact the

Flowserve Materials Engineering Group at (937) 226-4475.
Design & Type

The Flowserve valve design standards adopt ANSI B18.2.1

(1981) as the standard for fastener type and design. This

national standard requires that finished hex “head” cap

screws be used when the head of the fastener is turned. A

finished hex “head” cap screw and a heavy hex cap screw

have a bearing surface under the head to minimize frictional

resistance during tightening. They also comply to qualified

body dimen sions and fully formed head dimensions.

Cookeville Flow Control Division’s policy is to use finished

hex “head” and heavy hex “head” cap screws for all

pressure retaining fasteners. This includes top caps, packing

adjusters, plug adjusters, bottom caps, body halves or other

pressure retaining components. Compliance is made with

ANSI B18.2.2 (1987), Square and Hex Nuts, when studs and

heavy hex nuts are required. Additional information on these

items may be obtained from the Flowserve Corporation,

Cookeville Flow Control Division, Cookeville, Tennessee.

HOW tO sPECiFY

12 - B T L 4 8 1 - V P1

SIZE
2” - 24”

VALVE TYPE
B = Butterfly

LINER MATERIAL
T = PTFE
U = UHMWPE

BODY STYLE
W = Wafer
L = Lug

BODY MATERIAL
4 = A395 GR. 60-40-18

(2” - 24”)

DCI

1 = A744 GR. CF8M

(All Sizes)

D4

+ Coated Disc Insert Material: A395 GR. 60-40-18 (2”-24”) DCI

*Registered Trademark of Avesta AB

FLANGE

DRILLING

Blank = ANSI 150

P1 = DIN PN10
P6 = DIN PN16

ELASTOMER

SEALS

Blank = Silicone

V = Viton

ACTUATOR

0 = 10 Position

Locking Lever

1 = Enclosed Gear

9 = Bare Stem

(Specify Type)

STEM & DISC

MATERIAL

0 = A351/A744 GR. CD4M-CU

D100

1 = A351/A744 GR. CF8M

D4

2 = A351/A744 GR. CN7M

D20

3 = A494 GR. M-35-1

DMM

5 = A494 GR. N7M

DC2

6 = A494 GR. CW6M

DC3

7 = B367 GR. TI-PD 8A

TIP

8 = PFA COATED

DIPA

9 = UHMWPE COATED

DIPE

S = A351/A744 GR. CK-3MCuN 254 SMO*

3

BTV/BUV 2000

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