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accommodate average flow requirements, with the secondary unit contributing
additional capacity to cover entire operating range of the system.
5.1.5.2 Valve with internal float
Install rotary shaft packing box in opening indicated on drawing. Gaining access to the
interior of the vessel through the manhole, securely attach float rod with float to the
internal portion of the rotary shaft. Mount balancing lever on external portion of rotary
shaft and clamp counterweight so that float will be half submerged. This position is
established when force is required to either lift or submerge the float.
5.1.5.3 Valve with separate external float operator (mechanical type)
Install external float operator at opening level as shown on drawing. Connect
turnbuckle assembly to float operator arm and valve lever and adjust as described
above.
5.1.5.4 Valve with external float operator (pneumatic type)
Install external float operator at opening levels as shown on drawing. Connect
pneumatic control tubing between float operator and valve actuator. Adjust actuator as
described in instructions accompanying operator and valve assemblies.
5.1.6 Overflow Trap
This should be installed at floor level or as low as possible below the deaerator, for
maximum static head, assuring the greatest flow.
5.1.7 Insulation
The deaerator, storage tank, and all equipment carrying hot water or steam should be
thoroughly insulated to prevent condensation of steam and loss of heat. Sample
connection, thermometer wells and manholes should be left exposed.
5.2 Deaerator Flows
5.2.1 Make-Up Water
Make-up water pressure must be sufficient to overcome the head losses by internal
steam pressure, pipe friction, water inlet control and spray valves.
5.2.2 Low Temperature Returns
Condensate returns 30°F below the deaerator operating temperature, or cooler, should
be piped into the opening provided (as shown on drawing) between the water inlet
control valve and the spray valve. This permits the water to pass through the complete
deaeration cycle; and it is given preference over raw make-up.
5.2.3 Medium Temperature Returns
Returns having a temperature ranging from 30°F below, up to the deaerator operating
temperature should be piped to this opening.
5.2.4 High Temperature Returns
This opening is used for returns having a temperature higher than that of the steam
within the deaerator. They enter directly into the steam entrance of the scrubber
where they flash to steam and are utilized in the deaeration process.
5.2.5 Oil Contaminated Returns
If exhaust steam comes from reciprocating units such as pumps, engines or
compressors, it may contain entrained oil, which must be removed by an oil separator.
The oil separator must be of adequate size for maximum steam flow. It should be
preceded by a straight pipe equal in length to at least four pipe diameters to prevent
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