NOTE: Where motor starters for mechanical equipment
are provided in motor control centers, delete the
description of motor starters.
**************************************************************************
Electric motor-driven pumps shall be provided. Motors shall be
[splash-proof] [totally enclosed, nonventilated] [totally enclosed,
fan-cooled type] [totally enclosed, fan-cooled type, suitable for
installation in a Class II, Division 1, Group F hazardous location in
accordance with NFPA 70]. Motor starter shall be [manual] [[magnetic]
[across-the-line] [reduced voltage start]] type with [general-purpose]
[weather-resistant] [water-tight] [dust-tight] [explosion-proof] enclosure.
2.13.1
HTW Circulating Pumps
HTW circulating pumps shall be sized and designed for the specific
application. Pumps having a combined rating of flow and head that results
in a horsepower rating less than 185 kW (250 bhp) 250 bhp shall be
furnished to meet the design requirements of API Std 610. The pump shall
be end-suction, top discharge, and be supported at its centerline. Pump
sizes with higher ratings than the above shall be horizontal-split case,
multi-stage centrifugal pumps. Casing construction shall be either volute
or diffuser design and shall also be supported at its casing centerline.
All pump ratings shall have, nominally, an excess in capacity of 10 percent
above the maximum continuous rating of the service. The required Net
Positive Suction Head (NPSH) at the pump design flow, head, and speed shall
not exceed 80 percent of the available system NPSH at the same flow,
assuming a low level in the storage tank. The pump's suction specific
speed shall not exceed 9000 at the pump's best efficiency point (BEP). The
guaranteed NPSH requirements shall reflect 3 percent breakdown criteria.
The pump's head-capacity (H-Q) curve shall be constantly rising to shutoff
with no point of inflection. There shall be no restriction to operation at
any point from minimum continuous flow to design flow.
2.13.1.1
Suction and Discharge Flanges
Pumps shall have integrally cast suction and discharge flanges that shall
be drilled to meet the design pressure of the application. The maximum
operating temperature, for design purposes, of any feed pump shall not be
less than 205 degrees C 400 degree F. Casings shall be drilled, tapped,
and provided with vent and drain connections. Pumps designed for this
service shall not require cooling at ratings below 375 kW (500 bhp) 500 bhp.
This applies to both frame cooling or seal cooling. Below 375 kW (500
bhp) 500 bhp, pumps shall employ antifriction radial and thrust bearings,
lubricated by flinger rings in a sealed housing. Seals shall be mechanical
with air-cooled flush piping conforming to API Std 610, Plan 23. Above 375
kW (500 bhp) 500 bhp, pumps shall employ a single cooling circuit for both
cooling the oil being delivered by a forced oil system to sleeve radial
bearings and a floating shoe thrust bearing, coupled with the seal coolers
for both stuffing boxes. Mechanical seals shall also be provided. In both
cases, stuffing boxes shall be site-convertible to a packed box. Leakage
shall be no more than 0.025 L/hour 25 cc/hr for a seal life of no less than
25,000 hours. Bearing rating shall be not less than 100,000 hours (L-10
life) at the point of maximum load, as defined by ABMA 9.
2.13.1.2
Structural Steel Bases
Pumps shall be supported on structural steel bases that do not require
grouting in order to impart strength to the pump for static and dynamic
SECTION 15555A
Page 53
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