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

• 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

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

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

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

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

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

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

Drafting

Vacuum is created in pump by primer

Normal air pressure presses down on water and forces it into the hard suction lines

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.

Drafting; using the primer

Negative pressure created in intake lines and pump, water is forced by normal air pressure into the lines

Primer pump sucks air out of centrifical pump

Air is exhausted under vehicle

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

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

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

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

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

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.

Portable Pumps

• West Douglas has two types of portable pumps

• 250gpm pump on R133

• Mark II wildland portable pumps on T131 & T134

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

“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