SOG 18

Water Supply Operations

• Establish water supply using previously outlined procedures:
  • Circulate water using the tank to pump valve and the tank fill valve until the relay/attack pumper is ready.
  • Slowly open the supply discharge line while closing the tank to pump valve and the tank fill valve.
  • Increase engine rpm until correct psi is reached (100 psi preferable).

Relay Pumper Operations

• Engage the pump and circulate water until ready to establish supply.
• Attach supply line to gated intake valve.
• Keep gate closed but open the bleeder valve.
• When all the air is exhausted, slowly open the gated intake valve.
• Slowly open discharge valve and supply the receiving pumper at designated pressure.
• If receiving excess pressure, use a separate discharge for a waste or dump line.

Constant Pressure Relay

• All pumpers should attempt to maintain 100 psi.
• Attack pumper can open an unused discharge to control excess pressure.
• All pump operators must monitor gauges and make corrections.
• When operating from a hydrant, once the residual pressure at the source pumper drops to 20 psi, the relay capacity has been met.

Exact Pressure Relay

• Source and relay pumpers should send water according to GPM being used.
• Use a 20 psi "nozzle" pressure to determine friction loss calculations in reference to the intake pressure of the next receiving engine.
• When operating from a hydrant, once the residual pressure at the source pumper drops to 20 psi, the relay capacity has been met.

Operating the Relay

• Once the relay is in operation, all pump operators should set the relief valve (if applicable).
• Engines with pressure governors should be set to RPM mode, except for attack engine.
• This engine should be set for pressure mode.

Shutting Down the Relay

• Shut down from the attack pumper first, working backwards from fire scene to source pumper.
• Each operator should follow the normal pump shut down procedures.

Points to Remember

• Pumpers are rated for their maximum capacity at 150 psi discharge pressure.
• Most fire hose is tested at 250 psi.
• A maximum working pressure of 200 psi in a relay operation allows for a 50 psi safety factor.
• Try to maintain a minimum residual pressure of 20 psi and a maximum of 50 psi.
• Radio communications between relay trucks will provide for successful operation; consideration should be given for a separate radio frequency.
• If operating from a hydrant, an engine discharge pressure of 100 psi may not be available due to limited hydrant capacity.

Drafting- Dry Hydrant

• When preparing to draft, proper truck placement is essential.
• Connection to a dry hydrant can be accomplished in the following steps:
  • Spot truck near the dry hydrant.
  • Attach drafting hose to truck intake and hydrant.
  • Ensure all connections are tight and valves are closed; even the smallest air leak may result in a failed attempt.
  • Place truck in pump gear.
  • Pull tank to pump valve and observe for bubbles in static source.
  • Close tank to pump valve.
  • Two stage pump - place in volume position; engines with pressure governors place in RPM mode.
  • Increase throttle rpm speed to approximately 1000 to 1200 RPM.
  • Pull primer valve.

Drafting- Static Water Supply

• Check the area around the static water supply for stability prior to positioning.
• Spot truck near the static water source.
• Connect drafting hose to truck intake and place in supply.
• 24" of water should remain around the strainer.
• Ensure all connections are tight, even the smallest air leak may result in a failed attempt.
• Open intake and close all other valves.
• Engage pump; two stage pump place in volume position; engines with pressure governors place in RPM mode.
• Increase engine speed to approximately 1000 - 1200 rpm.
• Pull primer valve.

Water Shuttle Operations

• The key to a successful water shuttle operation is to minimize the time that water shuttle apparatus are idle.

• Portable tanks (dump tanks) will be set up in an area that will allow for easy and timely maneuvering of apparatus.### Water Supply Operations

• Purpose: Establish procedures for conducting water supply operations.

• Scope: All Fire Rescue personnel responsible for firefighting efforts.

Definitions

• Attack Pumper: Pumper positioned at the fire scene, directly supplying attack lines.
• Source Pumper (Water Supply): Pumper taking water from a source, sending it to attack pumpers.
• Relay Pumper (Inline Pumper): Pumper or pumpers connected within the relay, receiving water from the source pumper or another relay pumper, boosting pressure, and supplying water to the next apparatus.
• Large Diameter Hose: Supply and relay hose used to move large volumes of water.
• Static Source: Body of water not under pressure or in a supply piping system, must be drafted from in order to be used.

Establishing Water Supply

• Ensure the area around the static water supply is stable before positioning the apparatus.
• Check the area around the static water source for stability prior to positioning.
• Spot the truck near the static water source.
• Connect the drafting hose to the truck intake and place it in the supply.
• Ensure 24" of water remains around the strainer.
• Use a roof ladder attached to the drafting hose to keep the strainer off the bottom of the static supply.
• A float may be required to assist in keeping the strainer off the bottom of the static supply.

Drafting and Priming

• Do not run the primer pump for more than 30 seconds to avoid damage.
• Newer trucks with pneumatic primers are limited by available air pressure on board.
• Intake gauge should register a vacuum.
• Observe the pressure gauge for reading.
• Listen for a pitch change in the pump.
• If no draft is established within 30 seconds, check all connections and reattempt.

Water Shuttle Operations

• The key to a successful water shuttle operation is to minimize the time that water shuttle apparatus are idle.
• Portable tanks (dump tanks) will be set up in an area allowing for easy and timely maneuvering of apparatus.

Hydrant Operations

• Safety is a priority: helmets, gloves, and bunker gear pants are required.
• The first arriving engine will communicate to the second arriving engine of their intentions and provide direction for completing the hose lay, connection, etc.
• The second arriving engine will be responsible for the supply line if not already accomplished.
• Hydrant flow rates can be greatly reduced with extended hose lays.
• Source pumping should be considered for any supply lay 500 feet or greater.

Relay Pumping

• In relay pumping, there is always a "source" pumper and an "attack" pumper.
• Depending on the length of the supply line lay, a "relay" pumper(s) may be placed between the "source" and the "attack" pumpers.
• Source pumping for structure fires should be considered for any supply lay 500 feet or greater.
• Hose lays over 1000 feet will likely require relay pumping from a "source" pumper to the "attack" pumper.
• Every additional 1000 feet will require the placement of a "relay" pumper.
• Always ensure each apparatus involved in the relay evolution maintains a full tank of water.