Bell & Gossett HT 202A SM Models CHXS Fixed Tube Sheet Heat Exchangers - Manual (Page 4)

PRINTED IN U.S.A. 6-95
Bell & Gossett
Morton Grove, IL, U.S.A.
For further information, contact Bell & Gossett Heat Transfer Products, 175 Standard Parkway, Cheektowaga, NY 14227,
Phone (716) 862-4171 — Facsimile (716) 862-4176.
8. All bolted joints should be tightened uniformly and in a dia-
metrically staggered pattern as illustrated below:
9. Frequently and at regular intervals, observe interior and exte-
rior condition of all tubes and keep them clean. Frequency of
cleaning should be according to scale build-up.
CAUTION: Neglect in keeping all tubes clean may
result in complete stoppage of flow through some
tubes with consequent overheating of these tubes, resulting
in severe expansion strains, leaking tube joints, and damage
to the heat exchanger.
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START
10. Exchangers subject to fouling or scaling should be cleaned
periodically. A light sludge or scale coating on the tube greatly
reduces its effectiveness. Therefore, low-fouling fluids should
be used in the shell side of all heat exchangers with non-
removable tube bundles. A marked increase in pressure drop
and/or reduction in performance usually indicates cleaning is
necessary, especially if the unit has been checked for air or
vapor binding and this has been found not to be the cause.
Since the difficulty of cleaning increases rapidly as the scale
thickens or deposits increase, the interval between cleanings
should not be excessive.
ANODES
1. Some exchangers may be equipped with renewable anodes.
The purpose of the anodes is to inhibit electrolytic corrosion.
In order to remain active the anodes must be kept free of scale
or other surfaces coatings.
2. On some applications where electrolytic corrosion is not a
problem, pipe plugs may be substituted for the anode. The
pipe plug material selected should be softer than the base
part to avoid pipe thread damage.
RENEWABLE ANODES
(ZINC)
FRONT HEAD
FRONT HEAD GASKET
REAR HEAD GASKET
MOUNTING LEGS
CORE
(BUNDLE & SHELL ASSEMBLY) REAR HEAD