2nd Class Fireman

• Dissolved solids
• Suspended solids
• Dissolved gases

Surface water and ground water.

External and internal treatment

• Prevent sludge from depositing on boiler surfaces
• prevent scale from forming on boiler surfaces
• prevent corrosion of boiler metal
• Prevent carryover with the steam leaving the boiler

• A Cation are positively charged ions
• A Anion are negatively charged ions

By coagulation or by filtration.

With the use of water softeners, demineralizers, and distillation.

By deareation or degassification.

A measure of the water's acidity or alkalinity.

The scale reads 0 to 14. (7 is neutral.)

Thru the DA, chemical pumps, injectors, or by slug feeders.

The ratio of impurities in the boiler water divided by the amount impurities in make up water.

Between 10.0 and 11.0

• Foaming is the existence of a layer of foam on the surface of the water in the boiler drum. (caused by excessive alkalinity).
• Priming is the carry over of slugs of water that are suddenly discharged from the boiler with the steam.

The continual discharge of inpurities and water with the steam.

Excessive alkalinity which causes foaming, high water level, and the failure of mechanical separators in the boiler.

• Sodium hydroxide (caustic soda)
• Ammonia

• Find true water level, 1/2 glass or better
• Open cooling water to blow down tank
• Open quick opening valve (inside valve)
• Open slow opening valve (outside valve) fully and close
• Close quick opening valve
• Check water level and close cooling water valve

Dissolved gases (O2 and CO2)

• Using the dry method the boiler would be drained cleaned and isolated from water and steam. Desicants would be placed in the boiler to prevent moisture. The dry method is used for long term shut down.
• Using the wet method the boiler would be drained cleaned and filled with warm treated water at a higher level than normal. Pressureised slightly above atmos. and isolated from steam and water lines.
• The wet method is used when the boiler may be needed on short notice.

• Reciprocating
• Rotary
• Centrifugal

To control the exact amount of water returning to the boiler.

• Single Element (senses drum level)
• Double Element (senses drum level and steam flow)
• Triple Element (senses drum level, steam flow, and feedwater flow)

A safety valve is designed to relieve pressure in a boiler that has exceeded what the valve was set for.

• Gauge presssure is the pressure which does not include ambiant pressure.
• Absolute pressure is gauge pressure plus ambiant pressure.

The three ways heat can be transfered.

The superheater safety valve is the lowest set valve, therefor it will lift first to allow steam flow to prevent over heating of the superheater.

• Single (drum water level)
• Double (drum water and steam flow)
• Triple (drum water level, steam flow, and feedwater flow)

At least once a year.

The melting of one ton of ice in 24 hrs.

• Safety relieve valve
• Non-return valve
• Check valve
• Low water cut-out sensor
• Fire sensor

• Air that is supplied to the combustion process that supports both primary and secondary air.
• Often introduced into the combustion process in a different location.

To remove explosive gases before lighting the fire.

970.3 btu's per pound.

• Volume: oxygen= 20.91% nitrogen=79.09%
• Weight: oxygen= 23.15% nitrogen=76.85%

It is used as an oxygen scavenger.

Positive displacement and non-positive displacement.

Reciprocating, rotary, centrifugal, and jet pumps.

High pressure stream of fluid is directed through a nozzle designed to produce high velocity. The high velocity fluid creates a low pressure area in the mixing chamber causing the suction fluid to flow into the mixing chamber.

130 to 150F

Steam, compressed air and water.

Close steam supply, exhaust valves and drain pump. Lock out tag out pump. Then center the pistons, plumb the rocker arms, square the valves over the ports, equalize the lost motion and move one piston off center.

• Lost motion is play in the connection of the valve rod to the steam valves in the steam chest.
• Lost motion causes a pause at the end of each stroke to allow the water valves to close tightly.

• Too much lost motion will cause the piston to strike the cylinder head.
• Too little will cause the piston to short stroke.

A cushioned valve prevents the steam piston from striking the cylinder head by trapping steam in the cylinder to cushion the piston.

Area = d2 x .7854 6x6x.7854=28.27 in2

Yes. Because the net effect of the piston rod on the displacement is equal on both sides of a duplex pump.

Both are positive displacement pumps.

Both are typically used to pump heavy fuel oils.

Cavitation is the sudden formation and collapse of low pressure bubbles in water by mechanical forces.

Parcially closing the discharge valve may be done as a temporary fix while you further investigate the cause.

Provide correct net positive suction head (NPSH) to the pump.

As the impeller rotates water enters the center and is thrown outward by centrifugal force. The water leaves the impeller at high velocity and is converted to pressure in the volute section of the pump.

• Advantages: inexpensive, few moving parts, low vibration
• Disadvantages: alignment is critical, inefficient at some loads, cavitation

The pressure exerted by the height of a given fluid, in feet of head, or psi

The minimum suction conditions necessary to prevent cavitation in a pump.

The kinetic energy per pound due to the vertical distance traveled by fluid.

• First number: diameter of steam piston in inches
• Second number: diameter of fluid piston in inches
• Third number: length of the stroke in inches

Confirm that the pressure gauge is correct by attaching another gauge.

The latent heat of vaporization increases.

4.33 psi

• 970.3 BTU's is the latent heat of evaporation for one pound of water.
• 2.31 is the vertical height in feet of one pound of water.
• .491 is the pressure of 1 inch of mercury.
• 14.7 psia is atmospheric pressure.

Specific gravity is the weight of any substance when compared to the weight of water.

Specific heat is the amount of heat required to raise the temperature of one pound of any substance one degree F.

An open feedwater heater or (D.A.) is a heat exchanger in which the steam and water come in direct contact

A closed feedwater heater is a shell and tube heat exchanger in which the steam and water do not come in direct contact.

33,475

A fire tube horizotal return tubular boiler.

The reinforcing pad strenthings the connection around the blow-down tube at the bottom of the boiler.

As the water level drops within the drum, the steam space inside the tube (thermostat) increases causing the tube to expand. This expansion causes the tube to move a mechanical linkage which will open the regulator valve. The opposite will happen as the level in the drum begins to rise.

As the level in the boiler drops. so does the level in the inner tube creating a larger steam space within the inner tube. The latent heat from the steam in that space is given up to the condensate in the outer tube causing the condensate to expand. The expansion of the condensate pushes on the bellows moving the regulator valve towards the open position allowing more water to enter the drum. If the water level rises, the opposite will occur and the valve will start to close.

• Balanced draft is produced by using an FD fan and an ID fan together.
• Forced draft is produced when an FD fan pushes air into the boiler.
• Induced Draft is produced when an ID fan draws air through the boiler.

OUTPUT DIVIDED BY INPUT

Four passes.

Economizer and Regenerative air preheater.