McDuff WTP High Service Pump Replacement

Transcription

1 T E C H N I C A L M E M O R A N D U M MCDUFF WTP HIGH SERVICE PUMP REPLACEMENT McDuff WTP High Service Pump Replacement PREPARED FOR: PREPARED BY: Capital Budget Planning Craig Jones DATE: 02/10/2015 Revised 07/18/2016 Introduction & Background Revised by Mike Hersey 08/24/2017 The McDuff Water Treatment Plant (WTP) is located at 1040 McDuff Ave South. It was constructed in 1941 and has a FDEP permitted capacity of MGD. With the repurposing of the Main Street WTP to provide water to the South Grid, the McDuff WTP is a critical element to the regional system. The existing High Service Pumps (HSP) facilities are nearing the end of their service life and in need of replacement. Limited operational flexibility and excessive cavitation from NSPHa reductions from suction lift and long run of suction piping are additional concerns. The existing facility is equipped with six (6) service pumps. The HSPs numbered 1 through 5 are 150 HP rated for 2600 GPM at 170 FT TDH with 12-inch suction and 8-inch discharge. The HSP numbered 6 is 100 HP rated for 1500 GPM at 170 FT TDH with 8-inch suction and 8-inch discharge. One of the 150 HP pumps was replaced in early The pump header piping is 12-inch suction and 10-inch discharge. Under high demand the pumps will lose prime due to low water level in the ground storage tank, and during low demand the pumps will lose prime when all pumps are off. To resolve this issue, the facility is equipped with a vacuum priming system. This project will evaluate and if necessary, replace the yard piping and the vacuum priming system. The project will also replace the existing HSPs and motors, pump piping, vacuum priming system and motor control center (MCC). Variable frequency drives (VFDs) will be installed to give the proposed pumps variable speed capability. The existing aerators will be replaced on the ground storage tanks and the existing exhaust fans will be evaluated for replacement. Justification Pump Replacement The five oldest high service pumps are to be replaced. Because the proposed pumps will have variable speed drives and the north grid of the distribution system served by this facility is being reconfigured, pump ratings will likely not be identical to those of the existing pumps. To maintain our current DEP permit they shall be within 10% of the permitted duty point. JEA will perform hydraulic modeling of the system to determine flow and pressure requirements for the McDuff WTP. This information will be utilized by the engineer to select pump ratings. If required, replacement or modification of concrete pump base to suit proposed pump. Pumps shall be horizontal split-case, single-stage, double-suction pumps. Shaft seals shall be cartridge type, mechanical. Impellers shall be 316 or 316L stainless steel. Pump motor synchronous speed shall not exceed 1,200 RPM for motors of 250 HP and larger. Pump motor synchronous speed shall not exceed 1,800 RPM for motors smaller than 250 HP. 1

2 Industry standard cavitation parameters and Hydraulic Institute design guidelines should be observed. Electrical System Upgrades The service and MCC will be replaced as part of this project. Design criteria and scope are as follows: New 480 volt utility electrical service Evaluate whether a standby generator is required New air-conditioned electrical room New MCC in proposed electrical room High service pumps variable frequency drives (VFDs) integral to MCC Harmonic distortion limits per IEEE 519 Relocate PLC/SCADA equipment to electrical room Routing of new HSP motor feeders and controls to electrical room Connection of all existing and new equipment to new MCC Lighting per Illumination Engineering Society (IES) Fire Alarm per NFPA and Fire Marshall recommendation Equipment layout in electrical room in compliance with fire egress requirements New wiring from reservoir exhaust fans to new MCC Short circuit, protective device coordination and arc flash analysis including equipment labeling per NFPA 70E Removal of existing telemetry cabinet and other cabinets which are no longer utilized Replacement of existing HSP discharge magnetic flow meter and transmitter and existing discharge pressure transmitter Modification of PLC programing and control/instrumentation wiring to allow for VFD operation including start-stop sequence based on discharge pressure/flow, pump failure and low reservoir level cut-off and speed control based on system pressure. Engineer shall develop control strategy. JEA will provide programming. Piping Replacement The specific design requirements and criteria for piping replacement include the following: Evaluation of the condition and if necessary, replacement of the yard piping Replacement of pump suction piping and pipe supports between pump and the first above ground joint outside the building, including the leaded joint couplings. Replacement of pump discharge piping and pipe supports between pump and branch of discharge manifold in pipe trench. Rust removal, surface preparation and painting of discharge manifold in trench and replacement of flange bolts with stainless steel bolts Modification of discharge manifold as required to suit laying length of proposed flow meter Replacement of existing HSP discharge magnetic flow meter and transmitter and existing discharge pressure transmitter 2

3 Piping configuration design for proposed pumps shall be in accordance with Hydraulic Institute Standards. Piping shall be thickness Class 53 mortar lined ductile iron with Class 125 flanged ends in accordance with AWWA Standards. Pipe fittings and valves shall have AWWA Class 125 flanged bodies. Pump isolation valves shall be resilient seat gate valves with non-rising stems. Pump discharge check valves shall be rubber flapper type equipped with top-mounted position switches that are wired to the control system. All sleeved couplings and flange adaptor couplings shall be harnessed. Piping shall be designed to facilitate maintenance and replacement of system valves. Vacuum Priming System Replacement Specific design requirements and criteria for vacuum priming system replacement include the following: Vacuum pumps for priming system shall be the water ring type with duplex units mounted on a vacuum receiver tank. A continuous supply or potable water for the vacuum pumps shall be provided with necessary backflow prevention and drain piping from the vacuum pumps to the building sewer with air gap and trap. An air release valve with level switch wired to the control system shall be connected to the priming system at each HSP. Confirm existing piping is in good condition. Tray Aerators The existing tray aerators are undersized and at the end of their useful life. New tray aerators shall be designed to meet the following requirements: Aerators shall consist of two, seven tray cascade aerators each capable of supporting the entire design raw water flow rate. Aerators shall be supplied by a manufacturer of pre-stressed concrete tanks such as the Crom Corporation or the Precon Corporation. Both aerators shall be of similar design, design capacity and elevations. The reservoirs include a bypass to allow for aerator replacement without removal of the reservoirs from service. This capability shall be maintained. Exhaust Fans and Ventilators The existing reservoir exhaust fans and intake ventilators shall be evaluated for condition, capacity and functionality to determine if some or all would be in need of replacement. Maintenance of Plant Operation Engineer shall incorporate measures in the drawings and specifications to enable HSP operation during construction to the maximum extent feasible. The sequence of construction shall be constrained and temporary construction required as necessary. Specific allowable outages, their duration and coordination with JEA operations shall be specified. Lead Based Paint Abatement Based on the age of the facility, it is possible that existing coatings on the piping and building structure contain lead. JEA will have determinations made of lead content by a specialist company and provide results 3

4 to the Engineer. The engineer shall specify appropriate surface preparation or demolition of structures testing positive for lead based paint in accordance with all applicable lead abatement and Occupational Safety and Health Administration (OSHA) rules. Scope In general the scope of this project includes the following work and associated demolition of existing facilities: Replacement of five HSPs in the existing building Evaluation and if necessary, replacement of the yard piping Replacement of piping and valves and instrumentation associated with the HSPs Replacement of the MCC with VFDs and new 480 volt service Replacement of the vacuum priming system Repair and renovation of the interior of the pump building for new electrical equipment Replacement of the two tray aerators Evaluation and replacement, if necessary, of the exhaust fans and intake ventilators 4

5 Implementation Schedule FY MCDUFF WTP HIGH SERVICE PUMP REPLACEMENT RFP FY 2018 RFP Engineering Design Duration = 240 days FY 2019 Procurement Bid Duration = 150 days Construction Duration = 360 Days Construction Closeout Duration = 180 Days FY 2020 Project Management & Delivery Stage Project Definition 10% Schematic Design 30% Conceptual Design 90% Detail Design 100% Final Design Bid Construction To Project Delivery O&M PEC PEC PEC PEC PEC PEC OPB Established Trend Trend Trend 5

6 Cost Estimate and Expenditure Forecast (Current $) McDuff WTP HSP Replacement Contractor Cost Percent Material Labor Equipment MCDUFF WTP HIGH SERVICE PUMP REPLACEMENT Contractor Cost TOTAL Pumping Equipment $600,000 $600,000 Piping and Aerators $700,000 $700,000 MCC (including VFDs) $200,000 $200,000 Electrical Service Upgrade $70,000 $70,000 Equipment Wiring $100,000 $100,000 Instrumentation & Controls $70,000 $70,000 Building Renovation $50,000 $50,000 Contingency 35% $627,000 Total Contractor Costs $0 $0 $0 $1,790,000 $2,417,000 Additional Direct Costs Material Labor Equipment Other/Sub- Cont. TOTAL JEA Supplied Material & Labor $0 $0 $0 $0 $0 JEA Contingency 0% $0 $0 $0 $0 $0 Total Direct Costs $0 $0 $0 $1,790,000 $2,417,000 JEA Cost & Engineering Labor Sub-Cont. TOTAL Project Management 3% $72,000 $72,000 Engineering 12% $290,000 $290,000 Services During Construction 6% $65,000 $80,000 $145,000 Miscellaneous - (Permitting, 1% $18,000 $24,000 etc.) Total: JEA Cost and $0 $137,000 $18,000 $370,000 $525,000 Engineering Total Project Costs $0 $137,000 $18,000 $2,160,000 $2,942,000 PROJECTED EXPENDITURE FORECAST BY FISCAL YEAR (x 1,000) ACTIVITY FY 17 FY 18 FY 19 FY 20 TOTAL QUARTER 4th 1st 2nd 3rd 4th 1st 2nd 3rd 4th 1st 2nd 3rd JEA Cost & Engineering, 10% $4 $3 $45 $52 JEA Cost & Engineering, 30% $30 $75 $105 JEA Cost & Engineering, Final $67 $150 $6 $20 $30 $34 $32 $23 $362 Construction $190 $580 $630 $610 $407 $2,417 Closeout $3 $3 $6 TOTAL $4 $3 $75 $142 $150 $6 $210 $610 $664 $642 $433 $3 $2,942 6

7 Revision History Name Date Version Revision Notes Craig Jones 02/10/ Project request H. Vu 07/18/16 Revise scope (add yard piping), cost and schedule M. Hersey 08/24/17 Revised scope to add tray aerator replacement, and evaluation and replacement of exhaust fans and intake ventilators. 7