**Boiler Horsepower**

What is the boiler horsepower of a boiler generating 21,500 lbs of steam per hour at 155 psi?

The factor of evaporation is 1.08.

BHP = (LB/HR*fe)/34.5

BHP | Boiler Horsepower | BHP = (LB/HR*fe)/34.5 |

Lb/Hr | Pounds per Hour | BHP = 21500 * 1.08 / 34.5 |

Fe | Factor of Evaporation | BHP = 673 |

**Cycle of Concentration of Boiler Water
**What is the cycle of concentration if the chloride content of boiler water is 186 ppm and the feedwater chloride content is 38 ppm?

CYC = Bch/FCh

CYC | Cycles of Concentration | CYC = Bch/FCh |

Bch | Boiler Water Chlorides (ppm) | CYC = 186 / 38 |

FCh | Feedwater Chlorides (ppm) | CYC = 4.89 |

**Differential Setting
**What is the differential setting of an automatic pressure control that turns the burner ON at 80 psi and OFF at 105 psi?

delta S = P1 – P2

delta S | Differential Setting Delta | S = P1-P2 |

P1 | Cut-out Pressure Delta | S = 105 – 80 |

P2 | Cut-in Pressure Delta | S = 25 |

**Factor of Evaporation
**Water enters the boiler at 225°F. The boiler pressure is 100 psi and the boiler water temperature is 338°F. The latent heat is 881 Btu. What is the factor of evaporation?

FE = SH + LH / 970.3

FE | Factor of Evaporation | FE = SH + LH / 970.3 |

SH | Sensible Heat | FE = ((338 – 225) + 881) / 970.3 |

LH | Latent Heat | FE = 1.02 |

970.3 | Latent Heat of Evaporation of Water at 212°F (constant) |

**Force
**What is the force of 260 lbs of pressure exerted on 8 sq. in.?

F = P/A

F | Force (psi) | F=PA |

P | Pressure | F=260/8 |

A | Area | F=32.5 |

**Horsepower
**What is the horsepower of a pump that moves 450 lbs of water against a discharge head of 220 ft. In 1 minutes? Disregard friction and other losses.

HP = (d * F) / (t * 33,000)

HP | Horsepower | HP = (d * F) / (t * 33,000) |

d | Distance | HP = (220 * 450) / (1 * 33,000) |

F | Force (lb) | HP = 3 |

t | Time (minutes) | |

33,000 | Constant |

**Inches of Mercury
**How many inches of mercury are there at an atmospheric pressure of 14.5 psi?

in. HG = P / 0.491

Hg | Inches in Mercury | in. Hg = P / 0.491 |

P | Pressure (psi) | in. Hg = 14.5 / 0.491 |

0.491 | Constant (psi @ 1 in. of Hg) | in. Hg = 29.53 |

**Percent of Blowdown**

What is the percent of blowdown for a safety valve set to pop at 300psi and reseat at 275 psi?

%BD = (PP – RP) / PP

%BD | Percent of Blowdown | %BD = (PP – RP) / PP |

PP | Popping Pressure | %BD = (300 – 275) / 300 |

RP | Reseat Pressure | %BD = 8.33% |

**Rate of Combustion for Gaseous or Liquid Fuels**

A scotch marine boiler has a furnace volume of 45.5 cu. ft. if 3825.2 cu. ft. of natural gas is burned per hour and each contains 1100 Btu, what is the rate of combustion?

RC = H / (Vf * t)

RC | Rate of Combustion (Btu/hr) | RC = H / (Vf * t) |

H | Heat Released (Btu) | RC = (3825.2 * 1100) / (45.5 * 1) |

Vf | Volume of Furnace (cu. ft.) | (cu. ft.) RC = 92477.36 |

t | Time (hr) |

**Return Condensate Percentage in Feedwater**

What is the return condensate percentage in feedwater if the makeup conductivity is 834 µ ohms, the feedwater conductivity is 185 µ ohms, and the condensate conductivity is 65 µ ohms?

RC% (MC-FC) / (MC-CC)

RC% | Return Condensate % | RC% = (MC-FC) / (MC-CC) |

MC | Makeup Conductivity ( µ ohms) | RC% = (834 – 185) / (834 – 65) |

FC | Feedwater Conductivity ( µ ohms) | RC% = 84.40% |

CC | Condensate Conductivity ( µ ohms) | 0.84 |

**Static Head Pressure**

What is the static head pressure of a boiler operating at 275 psi?

SHP = Bpr * 2.31

SHP | Static Head Pressure | SHP = Bpr * 2.31 |

Bpr | Boiler Pressure (psi) | SHP = 275 * 2.31 |

2.31 | Multiplier | SHP = 635.25 |

**Steam**

How much steam will a 150HP boiler make in 2.5 hours?

S = HP * 34.5 * T

S | Steam | S = HP * 34.5 * t |

HP | Horsepower | S = 150 * 34.5 * 2.5 |

34.5 | Constant (lb/hr) | S = 12937.50 |

t | Time (hr) |

**Temperature Conversions**

Convert 92°F to °C.

°C = (°F – 32) / 1.8

°C = (92-32) / 1.8

°C = 33.33

Convert 30°C to °F

°F = (1.8 * °C) + 32

°F = (1.8 * 30) + 32

°F = 86

Total Force

What is the total force of 120 psi acting on 4 sq. In?

TF = P*A

TF | Total force (lb) | TF = P*A |

P | Pressure (psi) | TF = 120 * 4 |

A | Area of Valve Disc Exposed to Steam (sq. in.) | TF = 480 |

**Water Column**

How high is a column of water that exerts 42.43 psi at the bottom of the column?

WC = P / 0.433

WC | Water Column | WC = P / 0.433 |

P | Pressure | WC = 42.43 / 0.433 |

0.433 | Constant (force per 1 ft of water depth) | WC = 97.99 |