drawing showing the "internal" construction of the heater shall accompany
each bid. Deaerator shall include an internal sparger tube for chemical
treatment injection. Boiler feedwater pump suction nozzle shall include a
vortex breaker. Deaerator shall be provided with all of the connections
shown on the drawings, as a minimum.
2.6.3
Deaerator Trim
Deaerator shall be provided with the following trim:
a.
Safety relief valve set to open at 83 kPa 12 psig, and of
sufficient capacity to protect the deaerator from excessive steam
pressure with the steam regulating valve in fully open position.
b.
Vacuum breaker valve.
c.
Water gauge glasses with shutoff valves to cover the full water
level range.
e.
Pressure gauges shall conform to ASME B40.100 and shall be
complete with siphon and isolation valve.
f.
Makeup steam control valve with strainer, bypass, inlet and outlet
valves. Valves to reduce steam pressure from [_____] kPa psig to
[_____] kPa psig, with capability to operate at up to [2.07]
[3.45] MPa [300] [500] psig inlet pressure. Reducing valve shall
be adjusted to maintain the desired terminal pressure, regardless
of fluctuations in the initial pressure. Valves shall be
single-seated, spring loaded, quiet in operation, and guaranteed
not to stick. Valve body 65 mm 2-1/2 inches and larger shall be
cast steel; 50 mm 2 inches and smaller shall be of bronze. Valve
trim shall be stainless steel, Monel metal, or approved
corrosion-resisting material. All parts subject to wear shall be
readily replaceable. Valves shall have seats and plugs faced with
cobalt tungsten carbide mixture, or be made of heat treated
stainless steel or high chromium steel guaranteed to resist
erosion. Seat and plug facing shall have a Brinell hardness of
not less than 450. Valve shall be installed with a strainer, a
bypass, [safety valve on deaerator] as indicated. Sensing line
shall be connected to the steam space in the deaerator. Control
valve shall be sized for a minimum capacity of [_____] kg/hour
lb/hour at design conditions, but shall not have a capacity
greater than [_____] kg/hour lb/hour for the same conditions.
Valve trim shall be selected to result in a noise level not to
exceed 85 dBA, measured 914 mm 3 feet from valve.
g.
Makeup water control valve with bypass and inlet and outlet
valves. Valve to operate at an inlet pressure of up to 552 kPa 80
psig.
h.
Pneumatic level controller.
Mechanical linkage control of makeup
will not be acceptable.
i.
Overflow trap or valve with float control.
j.
Insulation clips for 38 mm 1-1/2 inch block insulation.
k.
Lifting lugs as required.
SECTION 15846A
Page 44
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