SP-70 (maximum size 300 mm 12 inches) or steel, Class 300, ASME
B16.34. Valves shall have wedge disc, OS&Y, rising stem; each
valve 200 mm 8 inches and larger shall have globe valved bypass.
b.
Globe Valves and Angle Valves: Flanged or butt welded, cast iron,
Class 250, MSS SP-85 or steel, Class 300, ASME B16.34.
c.
Check Valves: Flanged or butt welded, iron body, Class 250 or
steel, Class 300, Type [_____] [lift] [swing] check, style [____],
ASME B16.34.
2.10.5.3
Valves for maximum working pressure of 2068 kPa (gage) 300 psigsteam at a
maximum temperature of 454 degrees C 850 degrees F or a maximum W.O.G.
pressure of 4653 kPa (gage) 675 psig at 149 degrees C 300 degrees F
(non-shock).
Valve sizes
65 mm 2 1/2 inches and larger:
a.
Gate Valves, Globe Valves, and Angle Valves: Flanged or butt
welded, ASME B16.34, steel, Class 300, rising stem, OS&Y. Gate
valves 200 mm 8 inches and larger shall have globe valved bypass.
b.
Check Valves: Flanged or butt welded, steel, Class 300, Type
[_____], [lift] [swing] check, style [_____], ASME B16.34.
2.10.5.4
ASME B16.5 and API Std 607 double stem seal type for bubble tight shutoff.
Seats and seals shall be TFE material. Ball and shaft shall be stainless
steel. Provide mechanical stops to prevent cycling valve in wrong
direction and self-aligning stem seal.
2.10.5.5
Valve Accessories
ASME B16.34 valve operating mechanisms including chain wheels, gear
operators, floor stands, electric motors, air motors and cylinder-type
actuating devices. Provide accessories as follows and as indicated.
a.
Provide power operators with remote position indicators on the
following valves: soot blowers, [_____], [_____].
b.
Provide floor stands and valve extensions on platforms and floors
for the following valves: deaerator drain valves, [_____].
c.
Provide motorized actuators or chain wheels with chain and guides
on valves with handwheel centerline higher than 2 meters 7 feet
above the floor or platform except where specified otherwise.
Chains shall extend from valve to within one meter 3 feet above
floor. Provide impact chain wheels on steam headers and other
locations where valve has a tendency to stick. When a valve is
motorized, provide hand operation for emergency.
d.
Provide gear operators on ball valves larger than 80 mm 3 inches
and on gate valves 200 mm 8 inches and larger.
SECTION 15511N
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