design pressure rating of 1724 kPa (gage) 250 psig at 232 degrees C
450 degrees F at the inlet, and 379 kPa (gage) 55 psig at 232
degrees C 450 degrees F at the outlet. Turbine shall also include
a stainless steel steam strainer, sentinel relief valve, sight oil
level indicator and two hand valves.
b.
Turbine Bearings and Shaft: Bearings horizontally split,
ring-oiled, sleeve type water-cooled. Shaft shall be stainless
steel sprayed or chrome plated under the packing glands. Shaft
seals shall be segmented carbon rings with springs and stops.
c.
Speed Governor: Variable speed oil relay NEMA Class [A] [D]
governor for speed limiting [and pneumatic operator to maintain an
adjustable turbine speed]. [Input to the operator shall be a 20
to 103 kPa (gage) 3 to 15 psig pneumatic signal.] [Provide an
electro-pneumatic transducer to accept the 4 to 20 mA signal from
the controller specified in VAMS Section 15901N CONTROLS AND
INSTRUMENTATION BOILER PLANT.] [Turbine shall go to maximum rated
speed on air failure.]
d.
Emergency Overspeed Governor: Completely independent of the speed
governor and shall operate a separate trip valve.
e.
Insulation: Turbine shall be insulated and lagged by the
manufacturer as specified in Section 15080 THERMAL INSULATION FOR
MECHANICAL SYSTEMS.
f.
Reduction Gear: High speed, heavy duty, double helical, full
pressure lubricated, horizontal offset type with a service factor
not less than 2 provided in a horizontally split casing. The gear
and pinion shall be spray lubricated from a pressure lubricating
system. The pressure lubricating system shall include a shaft
driven oil pump, strainer, cooler, pressure gage, low oil pressure
switch, relief valve, reservoir and piping. Provide a high speed,
gear type, forge steel coupling between the turbine and the gear.
Reduction gear and turbine shall be mounted on a common
baseplate.
g.
Turbine Trip: Provide solenoid valve to trip turbine on failure
of induced draft fan.
2.6.1.6
Noise Level
Noise level shall not exceed 85 dBA sound pressure level at 1 1/2 meters 5
feet above the floor and 1 1/2 meters 5 feet from the fan in any direction.
[Provide heavy duty sound attenuator with screen on fan inlet to meet the
sound pressure level requirements.]
2.6.2
Induced Draft Fan
**************************************************************************
NOTE: The fan type shall be specified in accordance
with FS W-F-2793.
**************************************************************************
FS W-F-2793, Type [_____], Class 2.
SECTION 15502N
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