Flowserve Nordstrom Dynamic Balance Plug Valve and Double DB Plug Valve - Manual (Page 11)

Flow Control
Nordstrom Valves
FCD NVENIM2005-01 Dynamic Balance ® Plug Valve and Double DB ® Double Isolation Plug Valve 11
be obtained from system engineers or the valve manufacturer to
determine the cause and to evaluate possible need for action.
Noise emitted from a closed valve is a special case and may indicate
seat leakage, which requires repair. A whistling sound may indicate
severe erosion of seating surfaces; gurgling and popping sounds
may signify less severe leakage.
4.6 Maintenance
Valves are properly considered to be a hybrid structure, a combina-
tion of a pressure vessel and operating machinery. Maintenance pro-
cedures, therefore, must reflect the requirements of the occasional
opening or closing of the machinery and the predominant operating
condition of the valve where pressure is continuously applied and
nothing is moving. The important performance parameters are pres-
sure boundary integrity, actuating effort required, and internal leak
tightness. Maintenance should address the importance of preserving
these performance parameters.
Valves that remain in one position for long periods of time may
be hard to operate and/or not function as well as when originally
installed. This reduction of operability can result from either a loss of
effective lubricants, aging of packing, surface corrosion of moving
parts, or from an accumulation of deleterious solids. In some appli-
cations it may be desirable to schedule periodic partial- or full-cycle
exercising of such valves.
Pressure boundary integrity requires basically sound pressure-
containing parts, a pressure-tight static seal at assembly joints, and
in most cases, an effective working seal between a moving stem
and the valve body. Maintenance of pressure boundary parts and
the static seal of assembly joints is not usually considered to be
a problem. However, continuous monitoring is recommended to
confirm that problems do not occur. The need for paint protection
against corrosion of exposed piping should be obvious from normal
observations of the system.
5 Dynamic Balance Plug Valve
Maintenance
5.1 Notice
This manual is intended as a maintenance guide for Flowserve
Nordstrom Dynamic Balance Plug Valves. Before working on any
Nordstrom valve or related product, the user should review and
fully comply with this manual and its warnings and with the user’s
company’s safety procedures.
If anything in this manual is unclear, contact the Flowserve Sulphur
Springs Customer Service Department for assistance.
Flowserve and its employees are in no way responsible for damage
to property or for personal injury or death that may result through
the use or misuse of any Flowserve Nordstrom product, publication,
or audio or visual aid.
c WARNING: Dynamic Balance Plug Valves described in
this manual may have been manufactured prior to Janu-
ary 1, 1986 and may have been equipped with gaskets that
contained asbestos. When servicing, disassembling, or
disposing of these products, avoid breathing the asbestos
fibers and dust. Dispose of the material in accordance with
local, state, and federal laws.
5.2 Customer Service
If at any time you require assistance from Flowserve in maintain-
ing your Dynamic Balance Plug Valve, call or write your customer
service representative at the number listed on the back cover of this
manual.
5.3 Field Service
Our sales representatives are the best in the business. They can
provide you with technical information about your Dynamic Balance
Plug Valve, and are available to visit your facility to conduct general
maintenance seminars.
In addition, Flowserve maintains a highly skilled staff of service
representatives, who can provide maintenance assistance over the
telephone, or can visit your facility to conduct maintenance seminars
or to assist you in the maintenance and repair of your Dynamic
Balance Plug Valve.