2.2.13
Heat Exchangers
Heat exchangers shall be provided as shown. Heat exchangers shall be of
the shell-and-tube design, either U-tube type or helical coil type. Other
types of construction are not acceptable unless prior written approval is
received. Heat exchangers shall be designed, fabricated, tested, and
stamped in accordance with ASME BPVC SEC VIII D1.
a.
Materials of construction shall be suitable for the intended
service except that no cast material shall be used. The
manufacturer's drawing submittal shall indicate the grade of
material that has been used, giving the full ASME specification
number designation for each component. U-tube materials shall be
furnished as light drawn temper; helical coils shall be furnished
fully annealed. The materials of construction on the shell side
[casing] shall be carbon steel. The tube side materials shall be
90-10 Copper-Nickel for the tubes, tubesheets, and channel bonnets
for U-tube designs. Tubing and headers for the helical coil
designs shall be 90-10 Copper-Nickel.
b.
Tube-to-tube sheet connections and tube-to-header connections for
helical coils shall be either rolled or welded for the condensate
cooler and lube oil cooler, and shall be welded for lube oil
preheater.
2.2.13.1
Lube Oil Cooling
Lube oil cooling and heat reclamation exchangers shall be furnished as part
of the engine. The designs shall provide for the oil to be on the outside
of the tubes and the cooling water on the inside. A thermal sensing unit
shall be provided in the oil outlet piping where it can sense the mixed
average temperature of the oil leaving the cooler and actuate the control
valve on the cooling water flow to prevent overcooling the lube oil.
2.2.13.2
Fuel Oil Preheating
If fuel oil preheating is required, this heat exchanger shall be provided
as part of the boiler package. The designs shall provide for the oil to be
on the outside of the tubes and the steam or high temperature water on the
inside. A thermal sensing unit shall be provided in the oil outlet piping
where it can sense the mixed average temperature of the oil leaving the
preheater and actuate the control valve on the high temperature hot
water/steam to ensure that oil temperature is in the proper range for the
2.2.13.3
Condensate Heat Exchanger
High pressure condensate heat exchanger shall provide heating of domestic
or boiler feedwater while reducing the condensate temperature to minimize
flashing in the condensate surge tank. The designs shall provide for the
condensate to be on the outside of the tubes and the cooling water
(domestic or boiler feedwater) to be on the inside.
2.2.14
High Temperature Water Heat Recovery Systems
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NOTE: Delete this paragraph if high temperature
water heat recovery is not utilized.
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SECTION 15845A
Page 14
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