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Water supply and drafting

Water supply and drafting. Objectives. Understand and be able to demonstrate the different hydrant lays and hook ups Explain/demonstrate how to operate from a tender Explain and demonstrate drafting Explain alternative methods of water supply. Hydrants.

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Water supply and drafting

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  1. Water supply and drafting

  2. Objectives • Understand and be able to demonstrate the different hydrant lays and hook ups • Explain/demonstrate how to operate from a tender • Explain and demonstrate drafting • Explain alternative methods of water supply

  3. Hydrants • There are several methods of setting up to operate from a hydrant, depending on the conditions at the scene, where the scene is, and how much water will be needed • Forward Lay • Reverse Lay • Split lay (or driveway or farm lay) • Spotting the hydrant

  4. Forward Lay • Hose is laid fom the plug to the fire • Must have communication with the F/F at the plug • Engineer must clamp the line at the fire as he/she is making the connection to the engine

  5. Reverse Lay • Used when there is less room to place the engine, the engine needs to draft, or the scene may be hazardous • Engine is stripped of needed equipment, and lays hose from fire to the water supply

  6. Split Lay • Used for long driveways and farm roads • Two engines lay from the end of the driveway; one up the driveway to the fire, and one from the driveway to the water source

  7. Spotting the Hydrant • This is hooking to a hydrant that is right next to the incident • Most engines carry short 20’ lengths to perform this connection

  8. Forward and split lay connections • When you have finished laying the line to the fire, CLAMP THE HOSE! • Next, pull the rest of the 50’ section off of the bed to ensure you have sufficient slack • Hook hose to your 2 ½” suction, call for water, and release the hose clamp

  9. Drafting • This is a common method of establishing rural water supply, and can be done from a dry hydrant, a porta-tank, or from a pond or lake • Drafting isnt actually “sucking” water, we are creating a vacuum in the pump and atmospheric pressure forces the water into the pump

  10. Drafting Vacuum is created in pump by primer Normal air pressure presses down on water and forces it into the hard suction lines

  11. Rules for Drafting • All connections must be as air tight as possible • All other discharges, intakes, the tank fill, and tank to pump must be closed • 10’ to 12’ is our maximum vertical distance from surface of water to the pump that we will be able to establish a draft • You will need to flow as least some kind of discharge to hold the draft once it is established.

  12. Drafting; using the primer Primer pump sucks air out of centrifical pump Negative pressure created in intake lines and pump, water is forced by normal air pressure into the lines Air is exhausted under vehicle

  13. Making a hard suction connection • Hook up the engine side of the draft lines first • Make sure all connections are as airtight as possible, use rubber mallet

  14. Flat Bottom strainers • Flat bottom strainers are used for porta-tanks, where they can draft down to 2 inches of water remaining in the porta-tank • This type of strainer prevents whirlpools as well

  15. Barrel strainers • These are for drafting out of ponds, lakes, streams • This strainer has to be kept off of the bottom of the pond or lake to prevent drafting silt and sand • Needs 24” of water all around the strainer

  16. Preparing to draft • Make sure all valves are closed, incvluding tank to pump, and tank fill. • Be ready to flow water once a draft is established, otherwise you wont be able to hold the draft

  17. Drafting • Pull the prime lever, and hold it until the compound gauge shows a vacuum, pressure gauge shows pressure on the discharge side • You may hear the water flowing into the pump as well • Primer oil will leak from the bottom when drafting • Don’t hold the prime lever for more than 20 seconds at a time

  18. Drafting • Once a draft is established, slowly open the discharge of the line you intend to operate • Watch the pressure gauge; if you have a sudden loss of pressure as you are opening the discharge, you have lost your draft.

  19. Portable Pumps • West Douglas has two types of portable pumps • 250gpm pump on R133 • Mark II wildland portable pumps on T131 & T134

  20. Ejectors • Ejectors work like foam eductors, using a small flow of water to draw more water into bigger lines • Can operate 100’ away from engine

  21. “Jet Strainers” • These strainers are flat bottom strainers with an 1 ½” connection that is pumped by one of the engine’s discharges • The incoming water forces more water through the strainer and into the intake lines

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