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Model HSC Pump Specification
A. General Description
The pump shall be a single-stage centrifugal horizontal split case pump, Liqua Flow Pump model HSC or pre-approved equal. Pre-approval must be obtained a minimum of ten days before bid date.
B. Materials of Construction
Casing………………………………… Cast Iron (ASTM A48)
Impeller………………………………. Bronze (ASTM B62)
Shaft………………………………….. Carbon Steel (AISI C1045)
Shaft Sleeve……………………………. Bronze (ASTM B62)
Case Wear Ring………………………… Bronze (ASTM B62)
C. Pump Construction
1. Casing: The casing will be of the horizontal split case design. The casing shall have tapped and plugged holes for priming, vent and drain. Removal of the upper half of the casing must allow removal of the rotating element without disconnecting the suction or discharge piping. Bearing and bearing housing must be removable without disturbing the rotating assembly. Each bearing arm will provide a reservoir area for accumulation of seepage from the stuffing box, and a drilled and tapped opening will be provided at the lower portion to allow piping by the Contractor to the nearest floor drain.
2. Impeller: It shall be of the enclosed type, sat in one piece. It shall be furnished all over, the exterior being turning and the interior being furnished smooth and cleaned of all burrs, trimming and irregularities. The impeller will be dynamically balanced to 6.5 G. and it shall be held securely to the shaft by a key of ample size and shall be locked in place by shaft sleeves.
3. Shaft Sleeves: The shaft sleeves shall be extended from the hub of the impeller, through the seal box, and beyond the gland. They shall be sealed at the impeller hub on the O.D. of the sleeve to prevent fretting of the Buna O-ring and to prevent pumped liquid from contacting the shaft. They shall beheld securely in place, designed so as to lock the impeller.
4. Case Wearing Ring: The pump casing shall be fitted with case wear rings to minimize abrasive and corrosive wear to the casing. The wear rings shall be of the radial type, shall have a shoulder machined around the circumference to match a machined shoulder in the casing to provide two sealing faces and to locate the rings in the casing. The rings shall be securely located from rotation by means of pins to the lower casing half.
5. Stuffing Box: a removable stuffing box, sealed to casing by way of O-rings, shall be on each side of the pump casing, designed with sufficient area for incorporation of either packing rings or mechanical seals.
6. Packing: Each stuffing box shall be fitted with rings of die-cut non-asbestos packing material constructed of interwoven graphite coated acrylic.
7. Packing Gland: Each stuffing box shall be furnished with a two-piece gland to securely hold the packing in place. The gland pieces shall be split to allow access to the packing without disassembly of the unit. Control of seepage shall be accomplished by the use of adjustable swing bolts.
8. Shaft: The pump shaft shall be on-piece, 416 stainless steel (ASTM A582), finished and polished on all sections. The shaft shall be of ample strength and rigidity and the shortest practicable distance between bearings shall be used to keep deflection and vibration to a minimum. The maximum allowable deflection of the shaft is 0.002” at any point of operation on the pump curve.
9. Bearings: The pump shall be supplied with a single row inboard bearing primarily for radial loads and a double row outboard bearing primarily for thrust loads. Both bearings shall be regreasable lubrication ball type, designed for 250,000 hours average life. Each bearing shall be mounted in a machined housing that is moisture and dust proof protected by the dynamic bearing devices. The housing shall have registered fits to assure alignment, pined to prevent rotation, and bolted to the bearing arms. Each housing shall be supplied with a grease fitting and a plugged relief port.
10. Mounting: The pump and driver should be mounted on a common, one-piece, fabricated steel baseplate with leakage collection and drain. The fabrication is designed to provide a solid foundation and positive alignment without distortion for the mounted equipment. Alignment is provided by the use of a stainless shims for longevity. The pump shall be directly connected to its driver by means of a flexible coupling. Couplings shall be enclosed in a standard OSHA coupling guard.