Lift Station Condition Assessment, Repair and Rehab the Full Monty. How to Participate Today

Transcription

1 Lift Station Condition Assessment, Repair and Rehab the Full Monty This webcast will provide unique perspectives regarding the Condition Assessment of Sewerage Lift Stations. The topics covered include how to develop a Lift Station Assessment Program, when to repair or replace, and an in-depth review of recently implemented and completed assessment programs. This webcast is sponsored by Woolpert. How to Participate Today Audio Modes Listen using Mic & Speakers Or, select Use Telephone and dial the conference (please remember long distance phone charges apply). Submit your questions using the Questions pane. A recording will be available for replay shortly after this webcast. 1

2 Today s Webcast is Brought to You by: WEF s Collection Systems Committee Webcast Subcommittee Rudy Fernandez, Committee Chair Louis Leon, Vice-Chair Bri Nakamura, WEF Liaison Webcast Sub-Committee Members John Nelson Mattie Engels Abraham Araya Thomas Curl Chris Gainham Scott Helfrick Chris Johnston Lisa Riles Reggie Rowe Chip Smith Dianne Sumego Special Thanks to WEF Staff: Bri Nakamura Heidi Tierney 2

3 David Powell Water Resources Engineer Woolpert Merat Zarreii CMOM Coordinator/CIP DeKalb County Watershed Management Manny Padilla Service Manager Flygt, a Xylem brand Lisa Riles Market Manager Flygt, a Xylem brand Lift Station Assessment Repair and Rehabilitation Maintenance Troubleshooting, Typical Failures Moderator David Powell PhD, PE Special Thanks to the City of Hampton Public Works Wastewater Operations! 3

4 Pump Station Condition Assessments How to Review a Hundred at a Time DISCLAIMER: Although the information contained herein is believed to be reliable, no warranty, expressed or implied, is made regarding the accuracy, adequacy, completeness, legality, reliability, or usefulness of any information, either isolated or in the aggregate, unless expressly specified. Neither is this information intended as a substitute for applicant s obligation to retain its own professional advice from an engineer, surveyor, attorney, or the like. 4

5 Agenda PS Condition Assessment What to Collect How to Collect What To Do With It City of Hampton, VA Overview Atlantic Ocean 5

6 Sewer Collection System Wastewater Operations Division 104 sewage pump stations 11,055 manholes 477 miles of sanitary sewer piping 136 square miles of coverage 46,054 customer accounts 73% of system is > 50 years old Founded in 1613 Types of Pump Stations Station age groups WW2 era ( ) Built by US Government 50 s 60 s era 2 wells, drive shaft or dry pit 70 s 80 s era 1 well, suction lift type 90 s 00 s era Replacements and 1 well, low volume Variety of custom or individual facility stations 6

7 Goal: Avoid SSOs! What Info to Collect? For all of their differences, they are almost the same Building Envelope (under and above ground) Pumps and Piping Electrical / Controls Operating Conditions 7

8 Building Envelope Surveyed Elevations FF, inverts Station equipment Fans, hatches, lights Wet and Dry Wells Pumps and Piping Date Installed Drawdown testing Failure/breakdown history 8

9 Piping and Valves Internal conditions cannot be explicitly known without extensive testing PMs are the best source of info Which valve works? 9

10 Electrical / Controls Limited knowledge pool Where do you stop? Tracking PM s/receipts Operating Conditions Gravity side Pump start/stop Depth to influent Depth to ground Control points Pressure side Static Head Where does it go? 10

11 How to Collect? Laptop / Pentop Data is consistent (2 vs. 2inch vs. 2in) Requires computer-savvy operators Paper forms Can be completed in phases Requires a lot of manual cleanup How to Collect? Pictures Work Order Review Depends on CMMS Can create custom reports/forms in CMMS to directly import data At a cost! 11

12 How to Analyze? The more the merrier Ops crews have institutional knowledge Engineers have big picture Variety of reviewers Know your limitations Structural condition? Eye on the prize reduce risk of overflows! Not every crack or chip is mission-critical Results and Lessons Learned More accurate tracking will reduce effort CMMS Work Order codes/fields Field access to work orders Accurate drawdown testing can be difficult Priorities must be discussed amongst all Capacity both dry and wet weather Operational / Occupational concerns Reliability 12

13 Pump Station Number What To Do With It Provide New Flow Meter Standby Generator Auto Transfer Switch Portable Generator Connection, Manual Transfer Switch Rehab Flow Meter Wet Well Level Sensor & PLC Discharge Pump Pressure Rehab Sensor Repair Repair fans Stucco on & duct work PS building Pump Control Panel Repair Emergency Generator Wetwell Wetwell Ladder Rehab 002 4" Mag. X X X X 004 X X X X X 005 X X X 012 X X X X 016 X X X X 020 X 021 8" Mag. X X X 022 X X X X 024 X 026 X X X 030 X X X X 032 X X X X X X 104 X 112 X X X X X 115 X X X 116 X X X X X X 125 6" Mag X X X X 126 8" Mag X X X X 131 X X X X X X 132 X X X X 142 X X X 159 X X X X 162 6" Mag X X X 164 X X 170 X X What To Do With It Consent Order changed so priorities changed Initial work focused on existing CIP projects PS work to coincide with gravity system work 13

14 Questions? Merat Zarreii, CMOM Coordinator DeKalb County GA Graduate of University of Alabama Huntsville Bachelors of science in Electrical Engineering years of experience in Water and Waste Water industry 15 years with DeKalb County department of Watershed management (678)

15 Lift Station Repair and Rehab, a case study Harmony Hills Lift Station Harmony Hills scope of Repair and Rehab Address reliability issues by installing a reliable 100% redundant system above the previous flood level. Provide Pressure and Flow data on forcemain. Address and resolve hydraulic issues causing pump failures. Provide all above information to the central monitoring station via SCADA System. 15

16 Reliability Solutions available Emergency Generator Permanent Portable Dual Utility Source Permanent Standby Engine Driven Backup Pumps Emergency Generator Permanent Pros: Provide power to existing pump systems in case of utility loss of power. Prevents spills due to loss of power. Cons: Requires an Automatic Transfer Switch (ATS). ATS is susceptible to Transient Voltage Surge (lightning or sudden line voltage increase). Dependent on Transient Voltage Surge Suppressors (TVSS). Only Prevents spills due to loss of power. 16

17 Emergency Generator Portable Pros: Provides power to existing pump systems in case of utility loss of power. May Prevents spills due to loss of power. Cons: Requires transport from warehouse to job site. Requires wiring and connection. Lift station must already have connections available. Only Prevents spills due to loss of power. Dual Utility Power Source Pros: Provides power to existing pump systems in case of utility loss of power from one source. Prevents spills due to loss of power (if 2 nd source is live). Cons: Capital cost maybe extensive depending on how far the 2 nd source is to the station. Requires automatic controls to switch back and forth. Only Prevents spills due to loss of power. 17

18 Permanent Standby Engine Driven Backup Pumps Pros: Complete autonomous system capable of providing 100% redundancy to the lift station. Has its own controls and piping to perform the same work as the lift station. No direct connection to power utility service line entering the station. Provides complete redundancy to the lift station. Prevents spills due to almost any failure at the lift station. Permanent Standby Engine Driven Backup Pumps Facts: 119 lift station spill incidents reported in the state of Georgia from Of these incidents only 28 (23.5 %) were power related and could have been rectified by either a backup generator (or backup pump system) All 119 spill incidents would have been appropriately handled by a permanent standby engine driven pump system, including the 91 non power related occurrences. 100% 18

19 Fuel Types for Back up Engines Diesel Vs. Natural Gas Diesel typically cost more and runs with more noise and emissions. Fuel delivery will add cost and reduces reliability. Requires a double walled storage tank, which makes the entire enclosure much larger. Fuel in the tank has to be filtered periodically for debris and biological growth. Biological growth can happen in Diesel fuel! Dirty fuel leads to engine problems and require maintenance. Fuel Types for Back up Engines Diesel Vs. Natural Gas Natural gas typically cost less and runs with less noise and emissions! Fuel delivery is constant and increases reliability! Does not require a storage tank, which makes the entire enclosure much smaller. A small strainer at entry point will have to be cleaned periodically. Less engine problems and maintenance. 19

20 Provide Pressure and Flow data on forcemain. Always make sure operators have access to Pressure and Flow information when pumps are running. Establish the base line and the proper operating range of all pumps (flow and pressure). Have this information readily available on a laminated card inside pump station. Harmony Hills lift station 7.5 HP S&L pump 80 GPM at 28 PSI system pressure 150 GPM at 30 PSI with STBY Pump Tools to detect hydraulic issues and have an effective PPM To deal with these issues, each pump station should be equipped with: Discharge pressure sensor Flow meter Knowledge of these two parameters can allow the operator to identify such Hydraulic problems, and implement an effective PPM. 20

21 Hydraulic issues: self cleaning velocities (design considerations) Theoretical pump parameters will change quickly once the pump is in operation under real, everyday conditions Never design for min. flow velocity of 2.5 fps. Instead, a higher rate 3.5 to 5.5 fps is preferred. This allows for reduced velocities when the pump parts are worn out and no longer capable of producing original flow conditions. Hydraulic issues: Air Release Valves (ARV) ARV maintenance program can extend the life of the force main while ensuring efficient operation of the system. At a minimum each ARV must be inspected every 2 years for proper operation and Preventive maintenance performed. When replacing ARV consider new technologies and materials available today other than cast iron. Stainless steel, composite plastic material, resistant to corrosion! 21

22 Hydraulic issues: Forcemain Rehab, Cleaning the pipe Forcemain Cleaning is a crucial step that is often missed completely since in the past it was extremely difficult and expensive to perform. While Pigging a gravity pipe is very common, Pigging a force main is not. New technology has changed this picture dramatically providing extremely effective and relatively low cost Pigging solution. Forcemain Rehab ICE PIGGING 22

23 Forcemain Rehab ICE PIGGING Ice Pigging is a patented technology developed in Europe primarily for cleaning water distribution systems. It s value is even greater for cleaning forcemains to recover hydraulic capacity. It only needs a 1-2 inch connection to the forcemain, this can be the ARV connection to the forcemain. Forcemain Rehab ICE PIGGING It is cost effective specially for small pipes such as 4 to 8 inches in diameter. The longer the pipe the more ice is required. Making large quantities of Ice require time (Typically over night). Typically we fill 25% of the cleaning length with ice. 23

24 Forcemain Rehab ICE PIGGING It is cost effective specially for small pipes such as 4 to 8 inches in diameter. The longer the pipe the more ice is required. Making large quantities of Ice require time (Typically over night). Typically we fill 25% of the cleaning length with ice. Case Study Harmony Hills Lift station Location: Harmony Hills Lift Station (DeKalb County) Lift station rehabilitation project Scope of work: Addition of pressure and flow monitoring Replacement of generator with a permanent standby pump. Eliminate Hydraulic issues. Following instrument installation and commissioning, we observed: Flow rate well below design flow (38 GPM) System pressure roughly twice normal 24

25 Case Study Harmony Hills Lift station Historical reports from operators: Station not able to maintain level during rain events. Operators requested enlarging the existing 4 force main. Initial Step Taken: Inspected and repaired all 4, ARV s. All ARV s were confirmed operational However, abnormal conditions remained. Next Steps: Team elected to Pig the force main. Ice Pigging method was selected and utilized. It was determined that the 4000 feet forcemain be cleaned in 2 segments. Started at the station as 1 st segment, used 2 nd ARV connection to clean 2 nd segment. Case Study Harmony Hills Lift station Results: Once Ice Pigging was completed, system operation returned to normal. Pump flow rate increased from 38 to around 80 GPM (design level). System pressures returned to normal. Station has been running with no alarms or issues for the past 23 months. Power bill has been cut in Half! Cost to complete Ice Pigging < $10,000! 25

26 Questions? Submersible Pump Maintenance, Troubleshooting, Typical Failures 26

27 Manny Padilla, Service Manager Manny Padilla is a Shop Supervisor with 10yrs of Flygt pumps experience, works for Xylem Water Solutions Inc,USA. The company is a Global Market Leader in Water & WasteWater Transport & Treatment for Municipal and Industrial customers. Preventative Maintenance Include the pump environment and equipment, the pump and controls Proper preventative maintenance will increase the longevity of the system Weekly control panel checks can provide forewarning of potential problems Annual pump inspections can increase the life of the pump and prevent catastrophic failures 54 27

28 Safety Follow all safety guidelines Check for any hazards Use proper safety gear Only qualified service personnel should perform work and should never work alone Do not ignore health hazards Observed strict cleanliness A First-Aid kit must be handy Use Lock-out Tag-out procedures on electrical equipment 55 Wet Well Preventative Maintenance Properly ventilate well and check for gases before observing wet well Remove debris from top of wet well Check condition of power cables Check guide rails 56 28

29 Wet Well Preventative Maintenance Clean Level Sensors (Floats, Transducers) and check for proper operation Clean floats and check by tilting Check transducers by using known water height and verify in controls Check pump condition for proper sealing If water swirls or sprays around discharge connection, this could indicate improper sealing or sludge build up around pump 57 Wet Well Preventative Maintenance Pump the lift station down and clean side walls off Pump down to snore to help remove debris decrease build up Use one pump to pump down station to increase velocity in the discharge piping and reduce chance of clogging, other pump acts as back up 58 29

30 Dry Well Preventative Maintenance Follow same guidelines for wet well Check ventilation equipment Properly ventilate dry well and check for gases before entering Follow safety codes before entering dry well and opening wet well 59 Dry Well Preventative Maintenance Check for cracks and for water leaks in dry well Check sump pump for operation Check fittings for tightness Gate and plug valves need to be operated to prevent seizing and allow full closure when needed 60 30

31 Submersible Pump and Motor Submersible pump and motor are one unit Mechanical seals isolate motor from pumped material Upper and lower mechanical seals provide a seal chamber for lubricating and cooling the seals Mechanical seal failure can be caused by erosion, vibration or thermal shock Water intrusion into the motor causes motor failure Leak sensors notify the onset of a leak Motor failure can be caused by electrical malfunction 61 Typical Submersible Pump Motor Compartment Junction Chamber Seal Oil Chamber Hydraulic Wet End 31

32 Pump Preventative Maintenance (Annually) Run pump and listen for any unusual noise in upper and lower bearings Remove pumps and clean off build up Check for build up around power and lifting cables/chain Check wear ring clearances 63 Pump Preventative Maintenance (Annually) Remove pump from volute to remove any stringy material from around the impellers and any lodged or debris build up Check oil chamber for oil condition and levels Change oil (properly dispose of old oil and replace o-rings) Meggering the power leads Insulation check Water intrusion check Cable damage check 64 32

33 Checking a Pump with Multimeter Check each power lead to pump ground lead Open-winding is not grounded Resistance-winding is grounded Check between power leads to determine Resistance values shows what voltage pump wired for Open circuit could be open windings or cut cable Checking a Pump with Megger Disconnect pump power and ground leads Check with a cool motor Check power lead to pump ground lead High megohm good motor Medium megohn used motor, hot motor or slightly wet Low megohm deteriorated motor insulation, bad cable, wet windings Low-no megohm burnt motor, grounded leads, soaked cable or motor Do not megger pump if it has internal contactors or capacitors (single phase) 66 33

34 Check Pump Sensor Leads Check manufacturer s rating for sensor leads and to determine proper test procedure and function Usually sensor leads are checked by resistance Open resistance will show fault, possible open thermals Resistance values on leak sensors can determine if a leak has occurred Control Panel Prevention Maintenance (Weekly) Check incoming power Check run time meters and compare previous run times Check operating amps for each pump and compare to previous readings and full load ratings Check all electrical components and all connections including surge arrestors, alternators, relays and pump sensors 34

35 Control Panel Preventative Maintenance (Weekly) De-energize panel and check and tighten all connections Check conduit for tightness and sealing Replace sealing when floats or pumps are pulled through Check alarm light and horn operation Use a mild protective spray on the door gasket to ensure watertight integrity Pump Troubleshooting Pump is operating but not pumping Air locked will pull lower than usual amps Pump is not sitting on discharge connection properly Valves stuck will pull lower than usual amps Debris in front of inlet pipe listen for cavitation or rattling in the pump Wear ring is worn or impeller clearance needs adjustment Pump is turning backwards (three phase only) Pump may vibrate more Loose or broken impeller Pump will pull lower than usual amps Verify check valve on opposite side is closed Will see return flow around pump 35

36 Pump Troubleshooting Pump will not operate Check if phase monitor has tripped Check if thermal/leak sensor has tripped Check starter overloads Check for low level shut off Pump will operate but motor protection trips Check the impeller Check incoming power out of phase Megger the pump for wet or burnt motor Questions? 36

37 WOOLPERT Committed to assisting Clients with the continued improvement of their Collection Systems WOOLPERT We appreciate the opportunity to sponsor this Webcast! 37