Flowserve Nordstrom Dynamic Balance Plug Valve and Double DB Plug Valve - Manual (Page 6)

Flow Control
Nordstrom Valves
6 Dynamic Balance ® Plug Valve and Double DB ® Double Isolation Plug Valve FCD NVENIM2005-01
1.11 Operating Effort
Manually operated valves are usually designed to require a reason-
able amount of physical effort applied to handwheels or a handle to
open or close at rated working pressure. However, typical use of a
valve may involve a lower working pressure, resulting in reduced
operating effort. In some cases, lower operating effort can also be
achieved by opening a bypass valve.
In all cases, the purchaser should determine whether the manu-
ally operated valves selected can be operated under the anticipated
operating conditions by the personnel operating them. To prevent
applying damaging overloads, those personnel should receive cau-
tionary training on the use of oversize handwheels and “cheaters”.
Flowserve should be consulted for specific instruction on operating
torques.
2 Shipping And Storage
2.1 Introduction
Flowserve recognizes the importance of maintaining the as-built
condition of valves and has prepared this section to call atten-
tion to important considerations in the handling of valves prior to
installation.
Industrial valves as manufactured, tested, and ready for delivery to
users, are typically well designed products. They are properly fabri-
cated and inspected, and are capable of giving satisfactory service.
Valves enjoy a degree of inherent protection against degradation by
impact, impingement, or invasion of harmful materials after installa-
tion. However, the period between the production, test and instal-
lation in-line may involve substantial exposure to such degradation
that can adversely affect the performance of the valves.
Observing recommendations and cautions offered in this
manual should provide increased assurance of satisfactory valve
performance.
2.2 Handling
Appropriate care in handling valves should be complementary to the
degree of protection provided in preparation for transport. Valves
should never be thrown or dropped. Valves whose size requires han-
dling by a crane or lift truck should be “slung” or “rigged” carefully
to avoid damage to exposed valve parts. Handwheels and stems, in
particular, should not be used as lifting or rigging points for large
valves.
2.3 Storage
The storage problems to consider are generally the same as those
previously discussed relative to preparation for transport. The time
element is important, as conditions that would not be seriously
harmful for a period of a few days could result in need for costly
reconditioning if extended over weeks or months.
Valve end protectors should not be removed unless necessary for
inspection and installation.
Protection against weather should be provided. Ideally, valves should
be kept indoors with actual valve temperatures always higher than
the dew point.
If outdoor storage is unavoidable, valves should be supported off the
ground and/or pavement and protected by a watertight cover.
3 Installation
3.1 Introduction
A critical point in the life of an industrial valve is at the moment of
installation. The possibilities for degradation of the valve are numer-
ous. Conversely, exercising proper care in this process increases the
probability of trouble-free valve service.
The valve industry has prepared this section to provide useful
information, warnings, and reminders. A judicious selection of these
pages, delivered to the installation site with the valve itself, will
provide the opportunity for the person having the greatest need to
know to be informed or reminded of what is most important at the
time such information can be the most useful.
3.2 Inspection
The testing and inspection required by applicable standards and
specifications make it generally reasonable to assume that a new
valve, about to be installed in a piping system, has been prop-
erly designed and manufactured. Nevertheless, it is important to
recognize that in the transport, handling, and storage of a valve
between the time of manufacture and the time of installation, there
are numerous possibilities for accident or error that could adversely
affect valve performance.
It is therefore important to determine that the valve is in satisfactory
condition before installation. The following points are generally appli-
cable and may be helpful in avoiding subsequent valve problems:
a. Carefully unpack the valve and check tags or identifica-
tion plates, etc., against the bill of material, specifications,
schematics, etc.