Series HML Model: Two-Stage Splitcase www.cps-pumps.com Series HML: Two-Stage Splitcase Product Bulletin Casing: The casing is constructed of ASTM A48 class 30 high tensile cast iron or other specified material. It is of the single volute design with single suction, split on the hori- zontal centerline and has the suction & discharge nozzles cast integral with the lower half of the casing assembly. Heavy wall allows for generous corrosion allowance with a 20 year design life. Suction & discharge flanges are cast to 250 PSI dimensions and all models feature a 250 PSI case working pressure. Removal of the upper casing half gives complete access to the interior of the pump without disturbing suction or discharge connections. Each suction and discharge flange is drilled and tapped for easy connec- tion to the system piping. The suction and discharge flanges also feature a tapped connection for a suction and discharge gauge. Stage Arrangement: HML models have stage arrangements such that each stuffing box is only under first stage pres- sure. Furthermore, the maximum pressure difference across any of the stage pieces, separating the impeller chambers, is reduced to that of the first stage. Impellers are opposed or back-to-back to eliminate end thrust and volutes are stag- gered to balance radial thrust. This hydraulic balancing of all radial and axial thrust is obtained without the use of troublesome balancing disks or other devices that reduce efficiency. The efficiency is inherently high and sustained over long periods of time. Impellers: The impellers are of the single suction, enclosed, non-overloading type. They are cast of investment cast 304 stainless steel or other specified material, machined and dy- namically balanced. They are placed back to back to balance the axial thrust without the use of extra seal rings or other balancing devices. They are keyed to the shaft and secured by lock nuts. Optional impeller wear rings are available upon request. Shaft Sleeves: The shaft sleeves are of bronze, or other specified material, extending from the impeller hub through the stuffing boxes and secured to the shaft by two shaft sleeve locknuts. Stuffing boxes prevent leakage along the shaft while allowing freedom for the sleeve to expand inde- pendently of the shaft expansion. Casing Wear Rings: Case wear rings are of bronze or other specified material. They have large wearing surfaces to reduce leakage across the wearing surface and are of the labyrinth type with the diameter at wearing surface reduced to a minimum. Each wear ring is firmly secured in the cas- ing by dowel pins. Shaft: The shaft is manufactured of corrosion resistant 420 stainless steel, ground and polished to a smooth external SPECIFICATIONS HML Two-Stage Horizontal Splitcase Pumps surface. It is designed for extra stiffness to avoid all critical speeds in operation and is threaded for bearing lock nuts and impeller shaft sleeves. The portion of the shaft that is exposed to the pumped fluid is covered with renewable heavy wall bronze shaft sleeves, locked tightly against the impeller with right and left hand threads that cannot loosen during operation. The shaft is designed to use an inboard and outboard deep groove ball bearing for rotor support. Stuffing Boxes/Seal Chambers: The stuffing boxes/seal chambers are extra deep, being de- signed for packing and lantern ring or component mechanical seals. An internal Plan 1 flush is standard on the first stage side and optional on the second stage side. If the pumped fluid is not suitable for clean flushing then an external flush plan can be supplied upon request. Under each stuffing box is a drip pocket with tapped drain outlet. Leakage can be directed off to a location convenient to the end user. CPS-Pumps offers many different type of packing and mechanical seals. Packing can be supplied in carbon graph- ite and/or polymer designs. A variety of component and cartridge mechanical seals are available upon request. HML Bearings: Both the inboard and outboard ball bear- ings are of the single row, deep groove type, precision grade, with cartridge mounting, permitting the inspection, removal and/or replacement of the bearings without removing the top casing assembly. Each bearing is of extra large capac- ity for both radial and axial loads. The outboard bearing is confined rigidly in the bearing housing to take axial thrust, while the inboard bearing is set with sufficient clearance to allow for shaft expansion and radial loads. All bear- ings are sized to maintain a minimum L10 bearing life of 50,000 hours with many models exceeding 100,000 hours standard. Each bearing is designed for grease lubrication and is provided with a water slinger to prevent leakage from the stuffing box from entering the bearing housing. A grease fitting is furnished for each bearing. Each bearing housing is sealed from water leakage by the use of an oil lip seal. Each oil lip seal rides on a renewable and replaceable bearing spacer, protecting the shaft from oil lip seal wear. Bearing isolators are available upon request. Both bearings are of the cartridge design and can be inspected, removed and/or replaced without removing any other pump assembly component, greatly simplifying the repair process. Double row outboard and/or inboard bearings and oil lubrication is available upon request. Ring oiled lubrication is available upon request.