Pumping Apparatus Driver/Operator Chapter 10

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Questions and Answers

What is the purpose of placing wheel chocks when putting the fire pump into operation?

To prevent water from splashing out of the tank

To stabilize the vehicle for better pump operation

To provide added safety in case the apparatus moves unexpectedly (correct)

To assist in increasing the discharge pressure

What is the sole source of water supply for many incidents when putting the pump into operation?

Water supply from the onboard water tank (correct)

Water supply from a nearby river

Water supply from a separate water truck

Water supply from external hydrants

What must be monitored while the fire pump is in operation?

The water pressure in the onboard tank

All gauges associated with the engine and pump operation (correct)

The vehicle's fuel consumption

The surrounding environment for potential hazards

How can sufficient cooling be achieved?

Partially opening the tank fill valve Signup and view all the answers

What may happen if discharge flow volume is increased too much?

The intake pressure from the supply source may be reduced, causing damage to the pump or water supply system Signup and view all the answers

What residual pressure should drivers maintain on their master intake gauge during pumping operations?

At least 20 psi Signup and view all the answers

What must be done before opening the bleeder valve on a gated intake?

Make sure the gate valve is closed Signup and view all the answers

Why must water supply systems maintain a residual pressure of at least 20 psi within their mains?

To avoid overtaxing the water system, which may cause sediment and debris in older pipes to loosen, damaging piping or reducing flow Signup and view all the answers

What is a forward lay?

Stopping at the hydrant, dropping the end of one or more supply lines, and then proceeding to the fire Signup and view all the answers

What is one potential problem associated with a long forward lay with large flow demands?

The potential need for setting up a relay Signup and view all the answers

Why are hydrants located on 'dead end mains' typically considered less desirable?

They have higher amounts of sediment and deterioration, further reducing capacity Signup and view all the answers

What type of adapter will be needed at the hydrant during a reverse lay for an engine set up for forward lays?

Double female adapter Signup and view all the answers

What is the purpose of keeping the distance short when using 2.5 and 3 inch lines to supply a pumper directly from hydrant pressure?

To avoid excess friction loss Signup and view all the answers

What is a four-way hydrant valve used for?

Aiding in forward lays and allowing a second arriving pumper to connect and boost pressure without interrupting water flow Signup and view all the answers

What is the purpose of the reverse lay method in firefighting operations?

Supplementing hydrant pressure or performing drafting operations Signup and view all the answers

What action should the driver take after transitioning to an external water supply during a reverse lay operation?

Close tank-to-pump Signup and view all the answers

What does the reading of the pressure on the master intake gauge indicate when the pump is full of water and the pressure has stabilized with no water flowing?

Static pressure in the water supply system Signup and view all the answers

What is the purpose of opening a discharge drain valve?

To prevent overheating of the pump Signup and view all the answers

What should be done to prevent cavitation if the master intake drops below 20 psi?

Not increase the throttle Signup and view all the answers

How is the difference between static pressure and residual pressure used?

To determine how much more a hydrant can supply Signup and view all the answers

What should be done when shutting down a water supply operation?

Close valves in a slow and smooth motion, disengage the pump, and close the hydrant in the same manner to avoid water hammer Signup and view all the answers

What allows atmospheric pressure to force water into the pump?

Partial vacuum created by evacuating some of the air inside the pump Signup and view all the answers

What factor contributes to friction loss as water moves through the pump?

Inertia of water Signup and view all the answers

What affects the amount of friction loss in the intake hose?

Diameter, length of hose, intake strainer, and any adapters in use Signup and view all the answers

What is the surest indication of cavitation in a pump?

Lack of reaction on the pressure gauge to increases in the throttle Signup and view all the answers

At what altitude does a pump experience a loss of 1 inch of Hg?

1000 feet Signup and view all the answers

What happens when cavitation occurs in a pump?

All of the above Signup and view all the answers

What is the most important factor in choosing a draft site?

Amount of water available Signup and view all the answers

What can be used to lessen the chances of a whirlpool when using a traditional strainer?

A floating object placed above the strainer Signup and view all the answers

What may happen if a floating strainer is used for drafting?

The pumper may not achieve its rated capacity Signup and view all the answers

At what temperature range may the ability of the pump to reach capacity be adversely impacted?

Below 35°F or above 90°F Signup and view all the answers

What is the recommended depth for a traditional strainer to effectively approach its rated capacity?

24 inches of water over the strainer and 24 inches in all directions around the strainer Signup and view all the answers

What is the lowest water level that a low level strainer can effectively draft when using a portable tank or swimming pool?

Approximately 2 inches Signup and view all the answers

What happens to the pump and piping when pumping nonpotable water through the apparatus?

They should be thoroughly flushed with fresh water each time nonpotable water is pumped Signup and view all the answers

At what lift is it recommended to achieve an effective fire stream with a pumper?

No more than 20 feet Signup and view all the answers

What should be done before engaging the pump during a drafting operation?

Engage the pump after all connections are made and it is ready to be put into operation Signup and view all the answers

What is the first step for connecting to the pump after choosing a draft site?

Place the apparatus directly at the location from which the intake hose may be deployed Signup and view all the answers

What should be done if a two-stage pump's transfer valve is set to series (pressure) during drafting?

The pump may trap air that will need to be removed Signup and view all the answers

When drafting what should be done if the discharge pressure drops below 50 psi?

Pause to allow it to stabilize before opening the valve further Signup and view all the answers

What is recommended after successfully priming the pump?

Slowly increasing the throttle setting Signup and view all the answers

What may cause a loss of vacuum even with a very small air leak?

Without moving water Signup and view all the answers

If the apparatus priming device fails to operate, what alternative may be used to achieve a prime?

Water from the onboard tank Signup and view all the answers

Where is the most common place for a blockage to occur during drafting operations?

At the strainer Signup and view all the answers

How should drafting operations be shut down?

Slowly decrease rpms to idle, take the pump out of gear, and allow the pump to drain Signup and view all the answers

What is the purpose of a standpipe system?

To allow quicker access to water supply for attack lines in multistory buildings Signup and view all the answers

What type of hose may be installed at the standpipe connection?

Unlined, single jacket hose designed for occupant use Signup and view all the answers

How should multistage pumps be operated when supplying an FDC?

In parallel (volume) position Signup and view all the answers

What should the driver do if the FDC is found to have a frozen swivel on a 2.5 inch connection?

Add a double male adapter with a double female adapter to provide movement Signup and view all the answers

What should be done if there is any indication that water supply or pumping ability may be unattainable or interrupted?

Notify the officer or IC immediately Signup and view all the answers

What should the driver do if experiencing a pump or supply failure?

Enlist the help of another driver if available to gain a fresh perspective in search of the cause and solution Signup and view all the answers

What additional pressure should be added for each floor above the FDC that will have operating fire streams?

5 psi Signup and view all the answers

Study Notes

Fire Pump Operations Basics

Wheel chocks are essential for securing the vehicle and preventing movement during pump operation.
The sole water supply for many firefighting incidents often comes from fire hydrants.
Continuous monitoring of pump pressure and flow rate is crucial while the pump is operational.
Sufficient cooling is achieved through maintaining adequate water flow across the pump to prevent overheating.

Pump Flow Dynamics

Increasing discharge flow volume excessively can lead to decreased system pressure and potential system failure.
A residual pressure of 20 psi should be maintained on the master intake gauge during operations to ensure proper water supply.
Before opening the bleeder valve on a gated intake, ensure the system is depressurized to avoid potential hazards.

Water Supply System Requirements

Water supply systems must maintain at least 20 psi residual pressure to ensure sufficient water delivery during emergencies.
A forward lay involves firefighters connecting hose lines from the water source to the fire scene, often used for efficient water supply.

Hydrant Considerations

Long forward lays with large water flow demands may lead to excessive friction loss, reducing efficiency.
Hydrants located on 'dead end mains' can be less desirable due to potential sediment and reduced water quality.
During a reverse lay, a specific adapter is needed at the hydrant to accommodate the engine set up for forward lays.

Hose Supply Techniques

Keeping distances short when using 2.5 and 3 inch lines helps to maintain pressure and reduce friction loss from the hydrant.
A four-way hydrant valve allows multiple outlets for water, aiding in the distribution of water from a single hydrant.

Reverse Lay Operations

The reverse lay method is used to ensure that water supply is established after arriving at the fire scene.
After transitioning to an external water supply, drivers must monitor and adjust as necessary to maintain effective operations.

Pressure Indicators and Operations

A stabilized master intake gauge reading signals that the pump is full and operating correctly without flow.
Opening a discharge drain valve is vital for maintaining system integrity and preventing overpressure.

Managing Cavitation and Pressure

If the master intake pressure drops below 20 psi, immediate actions must be taken to prevent cavitation within the pump.
The difference between static pressure and residual pressure is utilized to assess water availability and system performance.

Shutdown Procedures

During water supply operation shutdown, it is critical to secure all valves and ensure water pressure is safely released from the system.
Atmospheric pressure aids in drawing water into the pump by maintaining a balanced environment.

Operational Considerations

Friction loss occurs due to water resistance as it moves through the pump and hoses, impacting efficiency.
The altitude significantly affects pump performance; a loss of 1 inch of Hg occurs at approximately 1,000 feet elevation.

Identifying Cavitation

The surest indication of cavitation is noticeable noise and vibration within the pump system.
Cavitation can lead to severe damage to the pump and reduce its operational capabilities.

Drafting Site Selection

The most critical factor in choosing a draft site is ensuring adequate water availability and accessibility.
Using a traditional strainer can lessen whirlpool formations, enhancing water flow into the pump.

Drafting Equipment Guidelines

A low-level strainer can draft effectively from water as low as 2% to 3% of the strainer length.
Nonpotable water can cause corrosion and clogging within the pump and piping systems.

Valve and Connection Procedures

Before engaging the pump during drafting, ensure that the strainer is submerged adequately.
If a two-stage pump’s transfer valve is in series mode during drafting, switch it to parallel for optimal flow.

Addressing System Failures

If discharge pressure drops below 50 psi while drafting, an immediate assessment of the system is necessary.
A small air leak can lead to a significant loss of vacuum in the system, requiring quick repairs.

Priming Alternatives and Common Issues

If the priming device fails, a secondary method, such as manual priming, can be employed to achieve water flow.
The most common blockage during drafting occurs at the strainer or in the intake hoses.

Standpipe Systems and Multistage Pump Usage

Standpipe systems are designed to deliver water to various floors in a building, improving firefighting efficiency.
When supplying an FDC (Fire Department Connection) with multistage pumps, operate in the appropriate range to avoid pressure loss.
If a frozen swivel is encountered at a 2.5 inch FDC connection, thawing methods or alternate connections should be utilized.

Emergency Protocols

If water supply or pumping becomes impossible, quick communication and a contingency plan must be activated.
In cases of pump or supply failure, immediate troubleshooting and backup systems should be implemented.
For each floor above the FDC, an additional pressure of 5 psi is typically required to ensure adequate water supply.

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