piping size to which it is connected. Valves shall be suitable
for operation on 1,034 kPa 150 psi water pressure, shall have
threaded ends, and shall be direct-acting to open on temperature
increase. The valve body shall have a 3.2 mm 1/8 inch hole
drilled through the wall separating the inlet and outlet ports so
that water circulation is not completely shut off. The valve
shall have a nonmetallic disc and means for preventing the water
from coming in contact with the range spring and sliding parts. A
manual adjustment of the setting shall be provided. The range
shall be 29 to 51 degrees C 85 to 125 degrees F and factory set
for 38 degrees C 100 degrees F. The temperature bulb shall be for
closed tank immersion with 13 mm 1/2 inch NPT connector.
b.
Makeup Water Heater Control Valve: A temperature controller shall
be installed in the high temperature return water line from the
feedwater heater coil. The valve shall be motor-operated and
shall operate in conjunction with the remote bulb temperature
controller. Both valve and controller shall be the reverse-acting
type failing in the closed position. The normal operating range
shall be fully open at 79 degrees C 175 degrees F and fully closed
at 100 degrees C 210 degrees F feedwater temperature. The
controller shall modulate the flow between these points. The
valve shall have a cast steel body, stainless steel trim, and
lubricated deep-type stuffing box with packing suitable for the
conditions. The valve disc shall be top-and-bottom guided of the
equal percentage type. The valve shall be single-seated for tight
closing, [_____] mm inch body size, flanged, passing [_____]
kg/sec pounds/hour of HTW at a maximum pressure drop of 15 m 50
foot head.
c.
LTW Heater Control Valve: A thermostatic control valve shall be
installed to operate in conjunction with a remote bulb temperature
controller. The valve operating range shall be 93 to 110 degrees
C 200 to 225 degrees F and valve shall modulate the flow of HTW to
maintain LTW between these temperatures. The valve shall have a
cast steel body with stainless steel trim, and lubricated
deep-type stuffing box with packing suitable for the temperature
and pressure conditions. The valve shall be single-seated,
[_____] body size, to pass [_____] kg/sec pounds/hour of HTW at a
maximum pressure drop of 15 m 50 foot head. The temperature bulb
shall be for pipeline insertion with 19 mm 3/4 inch NPT connector.
Necessary appurtenances including bypass valve and combination
temperature-pressure relief valve shall be provided.
d.
Domestic Water Heater Control Valve: A thermostatic control valve
shall be installed to operate in conjunction with a remote bulb
temperature controller. The valve operating range shall be 38 to
70 degrees C 100 to 160 degrees F and valve shall be adjustable
and modulate the flow of HTW to the heater between these
temperatures. The valve shall have a cast steel body with
stainless steel trim and lubricated deep-type stuffing box with
packing suitable for the temperature and pressure conditions. The
valve shall be single-seated, [_____] body to pass [_____] kg/sec
pounds/hour of HTW at a maximum pressure drop of 15 m 50 foot
head. The temperature bulb shall be for pipeline insertion with
19 mm 3/4 inch NPT connector. Necessary appurtenances including
bypass valve, strainer, and combination temperature-pressure
relief valve shall be provided.
SECTION 15555A
Page 63
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