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Introduction to Water Distribution. Water Solutions Inc 2006 Class #5 – 79 Slides. Hydrants & Meters. Types of hydrants & parts Hydrant inspection & installation Meter types, reading & testing Meter maintenance & repair Backflow and Cross connection terminology, types & locations
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Introduction to Water Distribution Water Solutions Inc 2006 Class #5 – 79 Slides www.h2osolutions.com
Hydrants & Meters • Types of hydrants & parts • Hydrant inspection & installation • Meter types, reading & testing • Meter maintenance & repair • Backflow and Cross connection terminology, types & locations • Types of Corrosion & monitoring systems www.h2osolutions.com
Fire Hydrants • Who maintains them? • Mostly the water utilities • Few communities the fire dept does. • Fire Hydrants are for public protection. • Failure to maintain and ensure operation can lead to the utility becoming liable for damage due to fire in event hydrant does not work. www.h2osolutions.com
Fire Hydrants • Placement of Hydrants • Other uses of Fire Hydrants • Flushing of water mains • Flushing sewers • Supply for street washers other municipal functions • Water source for construction jobs www.h2osolutions.com
Fire Hydrants • Other uses of Fire Hydrants • Hydrants on dead ends • Hydrants on busy streets • Hydrants in locations with high groundwater • Everyone who uses hydrants should be instructed in their proper operation www.h2osolutions.com
Fire Hydrants • Hydrant operation • Hydrants should only be placed on mains 6” or larger • Mains must have a minimum pressure of 20psi during fire flow demand • Hydrant operation can disturb sediments and increase customer complaints • Hydrants should always be closed slowly to reduce water hammer www.h2osolutions.com
Fire Hydrants • Types of Hydrants • Dry-Barrel Hydrants • Wet-Barrel Hydrants • Warm climate hydrants • Flush Hydrants www.h2osolutions.com
Fire Hydrants • Dry-Barrel Hydrant • Wet-Top • Dry-Top • Main valve and drain in base • Main valve opens and fills barrel with water. When main valve is closed the drain opens (at same time as main valve closes) and drains hydrant barrel. www.h2osolutions.com
Fire Hydrants • Dry-Barrel Hydrant (page 160) (Valve Classification) • Standard Compression • Valve closes against pressure • Slide Gate Hydrant • Main valve is a simple gate valve • Toggle (Corey) • Valve closes horizontally and barrel extends below branch line www.h2osolutions.com
Wet-Top • Operating rod or main rod stays submerged when barrel is wet • Dry-Top • Packing isolates threaded end of main rod from water when barrel is wet www.h2osolutions.com
Fire Hydrants • Dry-Barrel Hydrant (page 162) fig 6-8 (Breakaway) • Barrel designed to “break” on impact limiting damage to upper part of barrel. Operating rod also designed to “break” • Minimizes costs and time of repairs. www.h2osolutions.com
Fire Hydrants • Warm Climate Hydrants • Two part barrel (lower) is filled with water at all times with main valve at ground level to separate upper barrel • No drain mechanism www.h2osolutions.com
Fire Hydrants • Wet Barrel Hydrants • Barrel is filled with water at all times • NO main valve, instead each nozzle has a valve. • Cannot be used in areas that are subject to freezing • Large water waste if damaged in traffic www.h2osolutions.com
Fire Hydrants • Flush Hydrants • Entirely below ground • Usually Dry-Barrel type • Airport aprons & Taxiway’s • Pedestrian malls • Other areas where above ground obstructions are undesirable or cause a safety hazard www.h2osolutions.com
Fire Hydrants • Fire Hydrant Parts • Upper Section • Nozzle or “head” of hydrant • 5-sided operating nut usually at top of hydrant • Cap or “bonnet” over barrel of hydrant • Outlet nozzles • Threaded bronze – NAS Threads – (may differ) • (2) 2 ½” and (1) 4 ½ nozzles • Cast iron nozzle caps with nut to match operating nut www.h2osolutions.com
Fire Hydrants • Fire Hydrant Parts • Lower Section • Lower Barrel, Main Valve and Base • Lower Barrel carries water between base and upper barrel (conduit) • Buried so connection between upper barrel is 2” above ground. • Main Valve • Operating stem, resilient valve gasket & other parts • Base • Cast Iron and houses valve assembly • Flanged to connect to main www.h2osolutions.com
Fire Hydrants • Fire Hydrant Parts • Auxiliary Valves • Isolation Valve • Allows isolation of hydrant for repair or maintenance • Attached to flanges of Base (hydrant) and Main (supply) www.h2osolutions.com
Fire Hydrants • Fire Hydrant Inspection • Inspection checklist to include: • Direction to open hydrant • Counterclockwise and marked on hydrant –open to stops • Size & shape of operating nut • Depth of bury • Distance to main below surface • Size and type of inlet connection • Did you get what you ordered • Main valve size • Outlet nozzle sizes & configuration • Nozzle thread dimensions www.h2osolutions.com
Fire Hydrants • Fire Hydrant Installation • Installation considerations • Location • Set back 2’ from curbing • Pumper nozzle always faces the street • Footing and Blocking • Set on footing that will not rot or settle • Must be plumb (perfectly vertical) • Must be blocked to protect from movement “thrust” – excavation to retain undisturbed earth for block Common to use two shackles to connect base to main • Drainage • Color www.h2osolutions.com
Fire Hydrants • Fire Hydrant Installation • Testing • Hydrants should be pressure tested separate from the main • Open hydrant fully & fill with water • Vent air from hydrant • Apply pressure, up to maximum of 150psi • Check for leaks • Repair or replace components that leak www.h2osolutions.com
Fire Hydrants • Fire Hydrant Operation • Operated by (1) person with a 15” wrench • Dry-barrel hydrant should always have main valve opened or closed 100% • Failure to do so will leave drain valve partially open and loss of flow/water will occur • Main valves are not designed to throttle flow and should not be used to do so www.h2osolutions.com
Fire Hydrants • Fire Hydrant Maintenance • Visual Inspection • Listen for seat leakage • Check mechanical components • Actuate valve to test components • Drain • Operating Nut • Preventative Maintenance • Lubricate applicable components www.h2osolutions.com
Fire Hydrants • Hydrant Flow Testing • As mains age and systems expand flow testing should be performed to: • Determine the need for additional feeder or arterial mains • Determine the condition of the pipe & schedule cleaning if necessary. • Records should be kept of all hydrants www.h2osolutions.com
Fire Hydrants • Hydrant Safety • Hydrants can cause injury or problems if: • The full force of the water comes in contact with persons • Freezing temperatures and streams from hydrants can cause slick surfaces • Pedestrians as well as traffic • Potential cross connections to sewers • Connected hoses must be secured or they may flail about and strike someone www.h2osolutions.com
Water Meters www.h2osolutions.com
Types of Water Meters • Positive-displacement meters • Compound meters • Current meters • Detector-check meters • Proportional meters • Venturi meters • Orifice meters • Pitometers • Magnetic meters • Sonic meters www.h2osolutions.com
Water Meters • Large-Customer Meters (Compound Meters) • Large Customers = Municipal / Industrial / Commercial • Compound Meters • Current Meters • Detector Check Meters www.h2osolutions.com
Water Meters • Meter Sizing • Expected maximum demand for year • Pressure at point of connection • Friction losses in service line, meter and plumbing • Range of flow rates expected on service • Meter typically installed one size smaller than the service • Residential Meters • Most are 5/8 or ¾ inch • Commercial Meters • Most are 1-2” • Flushometer toilets may require larger meter • Meter guidelines www.h2osolutions.com
Water Meter Installation • General Considerations: • Not Installed in area where flooding w/ non-potable water is a problem • Up and downstream shut off for repair • Horizontal installation • Accessible • Easy to read either visually or remotely • Not a hazard to public • Seals attached to register to prevent tampering • Supported if larger installations • By-pass or multiple meters on larger services to prevent discontinuation of service if repair is needed. • BENEFITS OF A MANIFOLD www.h2osolutions.com
Water Meters • Manifold Installation • Benefits of a manifold • In a manifold installation all but one of the meters should have a backpressure valve on the outlet. This will allow subsequent meters to “register” only as flow increases. www.h2osolutions.com
Water Meters • Meter Connections • Screwed (Up to 1”) • Flanged • Meter Installation (indoor & outdoor) • Maximum and minimum heights • Types of meters • Access to meters • Large Meter installation • Supported • Adequate work space –20” from vertical walls and 24” of head space from highest point on meter • Thrust Blocking if necessary www.h2osolutions.com
Water Meters • Meter Reading • Gallons or Cubic Feet • May have multiplier 10X or 1,000X • Circular or straight • Direct Readout (Problematic ?) • Remote Reading • Signal is pulsed to a remote totalizer • Plug in readers • Electronic meter reading (Scanning) • Automatic meter reading www.h2osolutions.com
Water Meters • Meter Testing • Testing Frequency • Meters wear and may not register at low flows. • Meter Test Procedure • Run a variety of flow rates through meter to determine meter efficiency • Pass known quantities of water through meter at various flow rates • Meet accuracy limits on different rates www.h2osolutions.com
Water Meters • Meter Repair • Dismantling the meter • Cleaning the parts • Inspection of parts for wear • Replacing or repairing parts as necessary • Reassembly • Retest the meter • Replacement vs. Repair • Meter Records • Installation / Repair & History documented www.h2osolutions.com
Water Meters • Mainline Meters • Current • Proportional • Venturi • Orifice • Magnetic • Ultrasonic www.h2osolutions.com
Cross Connection www.h2osolutions.com
Cross-Connection Control • Definitions • Backflow • Flow of any liquid, gas, or other substances back into a potable water system • Backpressure • Backsiphonage • Cross-Connections • Any physical connection or structural arrangement that would allow backflow or backsiphonage between a potable water system and any other water source or system to occur. www.h2osolutions.com
Cross-Connection Control • Public Health Impact • Health impacts can result due to cross connections as a result of: • Improper design and construction of system • Modifications to existing system and structures • Cost cutting on plumbing and backflow devices • Failure to test and repair backflow prevention devices www.h2osolutions.com
Cross-Connection Control • Public Health Impact • Diseases attributed to cross-connections • Dysentery • Gastroenteritis • Hepatitis • Salmonellas • Chemical contamination attributed to cross-connections • Fertilizers • Pesticides • Boiler-chemical contamination www.h2osolutions.com