Flowserve BX2001 Durco - Manual (Page 3)

DURCO BX2001 USER INSTRUCTIONS ENGLISH 9-13
3
INTRODUCTION
The Big Max ® BX2001 is a superior quality ASME Class 300
and 150 valve available in standard PFA, fire sealed and two
metal seated versions. Offered in 2 in through 36 in sizes and
in both wafer and lug body designs, all are available with a
wide variety of packing options to meet your routine or most
rigid service requirements.
BX2001 effectively contains fugitive process media emissions
regulated by the federal Clean Air Act, including chlorine,
hydrofluoric acid and anhydrous HCI. This valve is an ideal
choice for precise throttling control or on-off service with
lighter weight piping systems and less expensive, energy
efficient actuators.
PRESSURE CONTAINING FASTENERS
Material Selection
Selecting the proper fastener material is the ultimate responsi-
bility 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 environment. Flowserve normally
supplies B7 (carbon steel) for ductile cast iron and carbon
steel valves. For stainless steel and high alloy valves, B8 (stain-
less 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 pro-
cess fluid. Determining compatibility to the process fluid goes
beyond a material being resistant to general corrosion because
the more important consideration 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
environ ments. 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 recommended 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
“Fasteners” chart (next page), or contact Flowserve’s Material
Engineering Group at (937) 226-4475.
Design & Type
Flowserve’s valve design standards adopt ASME 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 dimensions 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 ad justers,
bottom caps, body halves or other pressure retaining
components. Compliance is made with ASME 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 Flowserve Corporation, Cooke ville Flow
Control Division, Cookeville, Tennessee.
Materials Selection Chart
DS = ASTM A216 Gr. WCB (CAST STEEL)
DSNI = NICKEL COATED CAST STEEL
D2 = ASTM A351 Gr. CF8 (304 SS)
D4 = ASTM A351 Gr. CF8M (316 S. S.)
D20 = ASTM A351 Gr. CN-7M (DURIMET 20)
CK3M = ASTM A351 Gr. CK-3MCuN (254 SMO)*
DINC = ASTM A494 Gr. CY-40 (INCONEL 600)**
DMM = ASTM A494 Gr. M35-1 (MONEL 400)**
DNI = ASTM A494 Gr. CA-100 (NICKEL 200)
DC2 = ASTM A494 Gr. N-7M (CHLORIMET 2)
DC3 = ASTM A494 Gr. CW-6M (CHLORIMET 3)
D44 = ASTM A351 Gr. CF-8M with controlled ferite
D4L = ASTM A351 Gr. CF-3M
*Registered trademark of Avesta AB
**Registered trademark of International Nickel Co. Inc.
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