Pumps ?Horizontal Split Case, Centrifugal
Provide Armstrong Horizontal Split Case pumps, single stage, double suction type, with pump characteristics which provide rising heads to shut off.
Refer to pump schedules for pump flows, heads, motor speed, enclosure, efficiency and power requirements.
Pumps shall be Armstrong Series 4600 Horizontal Split Case type, each with flexible type coupling and OSHA guard and mounted, with motor, on a fabricated steel baseplate.
Pump Casing ?Cast iron, axially split, with 15?angle tilted parting to allow for lower NPSH requirements and to minimize pump dimensions. Suction and discharge connections, located in the lower casing, shall be flanged and of sizes indicated in the schedule and shall be drilled and tapped for gauge connections. Suction and discharge connections shall be on the same elevation. The top of the casing and the rotating assembly shall be removable without disturbing the piping connections.
Wearing Rings ?The pump casing shall be fitted with replaceable bronze wearing rings.
Impeller ?Bronze, double suction, fully enclosed type. Dynamically balanced.
Shaft ?Carbon steel, designed for minimum deflection and vibration.
Shaft Sleeves ?Shall be stainless steel and form components of the cartridge mechanical seals.
Mechanical Seals ?Each seal chamber shall be fitted with a cartridge type mechanical seal. The seal component shall be of stainless steel construction with carbon vs ceramic faces and EPDM secondary seal. The mechanical seal, shaft sleeve and seal plate shall be easily removable as a single component. Provide seal plates with factory installed flush lines.*
Bearings ?Supply dust tight deep groove ball bearings. With permanently sealed grease type lubrication.
Bearings shall be mounted in cartridge type housings, that are replaceable without opening the pump casing.
Bearings shall be removable by simply rotating the removal nut behind the bearing. No special tools or pullers are to be necessary.
Motor Horsepower ratings shown on the schedule are minimum acceptable and have been sized for continuous operation without exceeding full load nameplate rating over the entire pump curve, exclusive of motor service factor.
Mounting and Testing
Pumps shall be hydrostatically tested to 150% of the maximum pump working pressure.
The pump and motor shall be mounted and aligned at the pump manufacturer抯 factory on a common baseplate. Final alignment shall be made, on site, after the pump is installed and brought to operating temperature.
If supplied, the drip pan tapped connection shall be piped to the nearest drain.
*Seal flush line fittings, if required:
Supply in each flush line to the cartridge mechanical seal a 50 micron cartridge filter and sight flow indicator, to suit the working pressure encountered.
Filters shall be changed, by the installing contractor, after system flushing and on a regular basis until turned over to the owner.
Alternately for pumps with differential pressures exceeding 30 psig (2 bars):
Supply in each flush line to the cartridge mechanical seal a cyclone type separator, with sight flow indicator.