Flowserve 50165 Nordstrom Figure - Manual (Page 11)

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Nordstrom Figure 50165 and 50169 Dynamic Balance Iron Plug Valve FCD NVENIM2006-00 – 09/05
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d) Inspect the valve interior to the extent practical through the end ports. Make sure it is reasonably
clean, free from foreign matter and harmful corrosion. Remove any special packing materials.
e) If practical, actuate the valve through an open-close-open or close-open-close cycle. Inspect
any significant functional features such as guides or seat faces that are made accessible by such
actuation.
a Caution: Avoid contact with the valve closure element during cycling. It is usually desir-
able to leave the valve closure member in the position in which it was shipped following
such inspection.
f) Check the piping to which the valve is to be fastened for proper alignment, cleanliness and freedom
from foreign materials immediately prior to valve installation.
Flanged Joint Assembly
Flanged joints depend on compressive deformation of the gasket material between the facing flange
surfaces for tight sealing. The bolting must provide the mechanical force necessary to maintain the
compressive stresses on the gasket, as well as resist the normal pressure forces tending to separate
the joint. It should be recognized that with “brute force” alignment of misaligned flanges, sufficient
bolting force may not be available to sustain the required gasket loading and to resist the load caused
by the pressure separating force, resulting in a joint leakage problem. The following practices should be
observed for satisfactory flange joint make-up.
a) Check the mating flange facings. Do not attempt to assemble the flanges if a condition is found
which might cause leakage (e.g., a deep radial groove cut by a retracting cutting tool or a dent
across the face caused by mishandling), until the condition is corrected
b) Check the gasket materials. See ASME B16.5 for additional requirements for flange joints using low
strength bolting, (e.g., gray iron flanges or Class 150 steel flanges). Metal gaskets (flat, grooved,
jacketed, corrugated, or spiral wound), should not be used with these flanges.
types of Gaskets
There are two basic styles of gaskets used: full-face gaskets and flat ring gaskets. Full-face gaskets
cover the face of the flange and the bolting goes through them. Flat ring gaskets extend only to the
bolting.
What the Codes and Standards say about flanges and gaskets
aSME B16.1 covers Class 125, 250, and 800 Cast Iron Flanges and Flanged Fittings. Informa-
tion about these flanges is shown in the Flowserve Nordstrom Iron Plug Valves brochure under
Drilling Templates, Flange Dimensions, and Bolting Data.
aSME B16.1, Section 5.2 recommends the use of bolting conforming to ASTM A307 Grade B for
installing items that have cast iron flanges. A footnote to this section reads as follows:
For Class 25 and Class 125 flanges note: The carbon steel bolts prescribed for the flanges in this
standard are based upon using a flat “ring” gasket that extends to the bolts.
Where cast iron-to-cast iron flanges or cast iron to steel flanges are used with full-face gaskets,
higher strength bolts may properly be used.
Where cast iron flanges are bolted to steel flanges and flat ring gaskets are used, carbon steel bolts
prescribed in this standard shall be employed.