Specification for GRUNDFOS SL- Wastewater Pumps

Specification for GRUNDFOS SL- wastewater pumps Requirements _____ pcs of turnkey submersible non-clogging wastewater pump(s). Each pump comes with a _____kW (_____ HP) submersible electric 3-phase motor prepared of operation at _____ volts in 60 Hz complete with _____ feet of submersible power supply cable executed in extruded rubber compound according to UL Standard 62, ASTM B3 and ASTM B8. The pump shall be sized to match the electrical consumption of the motor running at full load and dimensioned according to current NEMA standards. The discharge of the pump shall be _____ inch discharge connection and the pump shall be capable of delivering _____US GPM at _____ feet TDH. The head at zero flow (shut off head) shall be _____ feet minimum. On the same curve shall be an additional point at ____ US GPM and ____ feet total head. Pump design Each pump shall have a guide claw attached to the pump discharge flange. A replaceable nitrile rubber seal shall be provided as an integral part of the guide claw to form a seal with the base plate. Metal-to-metal contact surfaces at pump discharge are not acceptable. The guide claw shall direct the pump down by two vertical guide rails to the discharge connection in a simple linear movement without tilting the pump side wards. No portion of the pump shall be supported directly on the bottom of the wet well, guide rails or lifting chain. A cast iron or stainless steel base plate with integral guide rail holders shall be provided. The base plate shall be designed with an integral 90° elbow, or adapt to a commercially available elbow. For each pump, _____ feet of lifting chain shall be included. The lifting chain must be dimensioned with a 2:1 safety factor. Pump construction The pump housing shall be of cast iron according to ASTM A 48 Class 25B. Without the use of tools, the pump housing shall be easily removable from the motor housing for full inspection of impeller and/or shaft seal. To ensure easy service, the use of bolts and nuts to keep the pump housing and motor housing together is not acceptable. Pump free passage for solids and impurities shall not be less than 2 to 3 inch spherical. The impeller design shall be either SuperVortex or semi-axial centrifugal flow design, with one sweeping vane and a wide flow channel i.e. single-channel impeller design. Impeller material shall be either cast iron, according to ASTM A 48 Class 25B (for SuperVortex)/ASTM A 48 Class 40B (for single-channel) or cast stainless steel (acc. to AISI 316) depending on the application in question. Furthermore, the impeller shall be statically and dynamically balanced. To ensure high efficiency over time and low overall operational and running costs, pumps fitted with single-channel impeller shall be equipped with a replaceable stainless steel wear ring according to AISI 304. Other major pump components shall be of cast iron ASTM A 48 Class 25B. All exposed fasteners and lock washers shall be of stainless steel according to A2.

Date: 2010-11-02

- 1 - Specification for GRUNDFOS SL- wastewater pumps Pump motor The motor shall be watertight according to IEC class IP 68 and NEMA MG1, Part 31, and incorporate Class H insulation materials rated for 356°F (180°C) , with temperature rise class B (176°F (80°C)) inverter rated duty. The pump and motor shall be able to operate continuously submerged and capable of handling liquids with a maximum temperature of 104°F (40°C). Stator housing shall be of cast iron according to ASTM A 48 Class 25B. The rotor shall be solid cast and dynamically balanced. Shaft ends shall be conical for safe securing of impeller. The pump shaft shall be of stainless steel or high-tensile steel in which case the shaft shall be fully protected against contact with the pumped liquid. Shaft bearings shall be permanently grease lubricated and sealed. Double mechanical shaft seals of the cartridge type shall be provided in a stainless steel housing and positioned inside the oil chamber. Materials of polymer shall not be accepted. The seals shall be oil-lubricated and the seal springs shall be operating in the oil fully protected against contact with the pumped liquid. The seals shall allow for rotation in either direction. All static seals at watertight joints shall be of nitrile O- ring type. The pump shall be equipped with a moisture-proof stainless steel cable plug where the unscreened conductors of the cable are cast into the plug by means of a two-component sealant to prevent moisture from entering the motor via the cable core. The use of a supply cable with leads that are not unscreened and embedded in a moisture-proof two- component sealant is not acceptable as water can flow directly into the terminal box during a flooding situation. The pump and electric cables shall be capable of continuous submergence without loss of waterproof integrity to a depth of 65 feet (20 meter). The motor shall have internal protection devices consisting of thermo switches embedded in the stator windings. A mechanically activated moisture switch shall be positioned in the lower part of the stator housing for FM-approved motors.

The service factor shall be a minimum of 1.15. A voltage tolerance of plus or minus 10% shall be allowed for the motor. Operation up to 104°F (40°C) ambient temperature and with a motor temperature rise not to exceed 266°F (130°C) shall be acceptable.

Design of power cable shall be according to UL Standard 62, ASTM B3 and ASTM B8 and NEMA standards. The length of the power cable shall be sufficient in order to reach the junction box without the needs to splice it with another cable.

The power provided by the motor shall be adequate. That is providing enough power to ensure that the pump is not overloading throughout the pump performance curve from 0 to maximum flow rate. Power cable The power cable shall include all sensor leads when additional sensors are required and must be designed for use with submersible pumps and shall be capable of continuous submergence without loss of waterproof integrity to a depth of 65 feet (20 meter). The cable shall allow a maximum conductor temperature of + 194°F (90°C) and a minimum ambient temperature of - 58°F (- 50°C). The conductor shall be stranded plain copper conductor according to UL Standard 62, ASTM B3 and ASTM B8. The insulation shall be extruded rubber compound according to UL Standard 62, ASTM B3 and ASTM B8. Bearings Rotation of pump shaft shall be by means of ball bearings. Motor bearings shall be permanently greased for life. The main bearing shall be a double-row angular contact ball bearing whereas the support bearing shall be single-row deep-grove ball bearing.

Date: 2010-11-02

- 2 - Specification for GRUNDFOS SL- wastewater pumps Shaft seal Double mechanical shaft seals of the cartridge type shall be provided in a stainless steel housing and positioned inside the oil chamber. Materials of polymer shall not be accepted. Pumps without a double mechanical cartridge shaft seal are not acceptable. The pump shall have a primary and secondary shaft seal capable of rotating in both directions. The pump shall have a primary and a secondary shaft seal. The material combination of the primary shaft seal of all pump types shall be silicon carbide/silicon carbide (SiC/SiC). For the secondary shaft seal, the material combination shall be carbon/ceramic. Sealing between the seal faces shall be based on extremely smooth and flat contact surfaces. The surfaces shall be in such close contact that no or only a very minute leakage can pass between them. The flatness and smoothness of the seal faces shall be in the magnitude of 0.0005 mm and the faces shall be finished by lapping. The shaft seal shall be placed in the oil chamber of the pump. The oil chamber shall provide a reliable sealing between the pumped liquid and the motor. The shaft seal shall be bidirectional, meaning that they can operate in either direction thus allowing for opposite rotation caused by back-flow of liquid through the pump. Impeller (for pumps with SuperVortex impeller) The impeller shall be of cast iron according to ASTM A 48 Class 25B or cast stainless steel (acc. to AISI 316) depending on the application in question. The impeller shall be designed as symmetrical multi vane winglets impeller capable of running against closed valve at maximum capacity without overloading the motor. The design must ensure flow entirely outside the impeller providing limited contact between the impeller and the pumped liquid and ensure that long fibers, rags and more passes freely through the pump without getting caught and without causing clogging or jamming. The impeller shall be keyed to the shaft and have an impeller bolt for locking the impeller to the shaft. The impeller shall be capable of passing a minimum of _____ inch diameter solid spherical. Impeller (for pumps with single-channel impeller) The impeller shall be of cast iron according to ASTM A 48 Class 40B, in single-channel design, statically and dynamically balanced of semi-axial centrifugal flow design with a long, self-cleaning and non-clogging vane. To ensure high efficiency over time and low overall operational and running costs, pumps fitted with single-channel impeller shall be equipped with a replaceable stainless steel wear ring according to AISI 304. The impeller shall be keyed to the shaft and have an impeller bolt for locking the impeller to the shaft. The impeller shall be capable of passing a minimum of _____ inch diameter solid spherical. Volute The volute shall be a single-piece cast iron according to ASTM A 48 Class 25B. The volute must be in non-concentric design with smooth passages large enough to pass any solids that may enter the impeller. The inlet and discharge size shall be according to the requirements. Protection The motor shall have internal protection devices consisting of thermo switches embedded in the stator windings. These shall open at 302°F (150°C) thus stopping the motor. The motor shall have an optional moisture sensor in the lower stator chamber. In addition there shall be a water in oil analogue sensor for continuous monitoring of shaft seal condition. All monitoring sensors shall be connected to a Grundfos sensor module which can be integrated to the control system and communicate with PLC controls and a communication package via 4 -20 mA signals.

Date: 2010-11-02

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