MATH AND MAINTENANCE FOR PUMPS AND BLOWERS TRAINING SEMINAR
FORCE WEIGHT OF WATER MEASURED IN POUNDS PRESSURE = FORCE PER UNIT AREA WEIGHT PER UNIT AREA
PRESSURE (PSI) = FORCE (LBS) / AREA (IN 2 ) P (PSI) = F (LBS) / A (IN 2 ) F P A
FORCE (LBS) = PRESSURE (PSI) X AREA (IN 2 ) F (LBS) = P (PSI) X A (IN 2 ) F P A
ONE CUBIC FOOT OF WATER FORCE = WEIGHT = 62.4 LBS PRESSURE (PSI) = FORCE (LBS) / AREA (IN 2 ) P (PSI) = F (LBS) / A (IN 2 ) P (PSI) = 62.4 LBS 1 FT 2 X 144 IN 2 /FT 2 P (PSI) = 62.4 LBS 144 IN 2 = 0.433 PSI
P = 0.433 PSI FOR ONE FOOT OF DEPTH PRESSURE DEPENDS HEIGHT OR DEPTH OF WATER DIAMETER OR AREA IS IRRELEVANT IF YOU DOUBLE THE DIAMETER OF A RESERVOIR OR CLARIFIER BUT THE DEPTH REMAINS THE SAME THE PRESSURE DOES NOT CHANGE
Dia = 30 feet Height = 20 feet
Height = 20 feet Dia = 30 feet Dia = 150 feet
F = Weight = Vol (gal) x 8.34 (lbs/gal) = A (ft 2 ) x H (ft) x 7.48 gal/ft 3 x 8.34 lb/gal = A (ft 2 ) x H (ft) x 62.4 lb/ft 3 A (in 2 ) = A (ft 2 ) x (144 in 2 /ft 2 ) P (psi) = F (lbs) / A (in 2 ) P = A (ft 2 ) x H (ft) x 62.4 lb/ft 3 A (ft 2 ) x (144 in 2 /ft 2 ) P = 0.433 (psi/ft) X H (ft)
0.433 PSI / FT 1 FOOT / 0.433 PSI 2.31 FT/PSI
STATIC PRESSURE DEPENDENT ON WATER DEPTH (HEIGHT) HEAD
HEAD
STATIC PRESSURE DEPENDENT ON WATER DEPTH (HEIGHT) HEAD PRESSURE HEAD ELEVATION HEAD
PRESSURE HEAD PRESSURE HEAD ELEVATION HEAD SEA LEVEL ELEVATION HEAD
STATIC PRESSURE PIEZOMETRIC SURFACE DEPENDENT ON WATER DEPTH (HEIGHT) HEAD PRESSURE HEAD ELEVATION HEAD DYNAMIC PRESSURE FRICTION LOSS
DEFINITION THE HEAD, PRESSURE OR ENERGY (SAME THING) LOST BY WATER FLOWING IN A PIPE AS A RESULT OF TURBULENCE CAUSED BY THE VELOCITY OF THE FLOWING WATER AND THE ROUGHNESS OF THE PIPE OR RESTRICTIONS CAUSED BY FITTINGS.
AKA SMOOTHNESS C-FACTOR HIGHER C-FACTOR SMOOTHER PIPE GREATER CARRYING CAPACITY SMALLER FRICTION LOSS C-FACTOR MAY DECREASE AS PIPE AGES PIPE DEPOSITS TUBERCULATION
INCREASING VELOCITY INCREASES FRICTION LOSS Q = A x V V = Q / A FLOW IF FLOW INCREASES VELOCITY INCREASES AREA IF AREA DECREASES VELOCITY INCREASES DIAMETER IF DIAMETER DECREASES VELOCITY INCREASES
MAJOR LOSSES AKA FRICTION LOSSES LOSSES IN THE PIPE MINOR LOSSES LOSSES DUE TO FITTINGS
HYDRAULIC GRADE = ELEVATION HEAD + PRESSURE HEAD
H.G. HYDRAULIC GRADE H.G. PSI HEAD PSI HEAD ELEVATION HEAD SEA LEVEL ELEVATION HEAD
HYDRAULIC GRADE = ELEVATION HEAD + PRESSURE HEAD EQUIVALENT TO THE ELEVATION OF THE WATER SURFACE IN A RESERVOIR
H.G. WATER SURFACE ELEVATION SEA LEVEL
HYDRAULIC GRADE = ELEVATION HEAD + PRESSURE HEAD EQUIVALENT TO THE ELEVATION OF THE WATER SURFACE IN A RESERVOIR HYDRAULIC GRADE LINE LINE CONNECTING HYDRAULIC GRADES
H.G. HYDRAULIC GRADE LINE H.G. HEAD HEAD ELEVATION ELEVATION SEA LEVEL
HYDRAULIC GRADE = ELEVATION HEAD + PRESSURE HEAD EQUIVALENT TO THE ELEVATION OF THE WATER SURFACE IN A RESERVOIR HYDRAULIC GRADE LINE LINE CONNECTING HYDRAULIC GRADES ALWAYS SLOPES DOWN IN THE DIRECTION OF FLOW FLAT AT NO FLOW WHAT CAUSES HYDRAULIC GRADE LINE TO SLOPE DOWN FRICTION LOSSES
H.G. HYDRAULIC GRADE LINE FRICTION LOSS HEAD HEAD ELEVATION SEA LEVEL ELEVATION
WORK ENERGY NEEDED TO MOVE ONE POUND MASS ONE FOOT MEASURED IN FT-LBS HORSEPOWER ENERGY PER MINUTE ONE HORSEPOWER DEFINED TO BE 1 Hp = 33,000 FT-LBS/MIN
MEASUREMENT OF THE AMOUNT OF ENERGY DELIVERED TO WATER WHp = Q (gpm) x TDH (feet) x 8.34 lbs/gal 33,000 (ft-lbs/min)/hp WHp = Q (gpm) x TDH (feet) 3,960
TOTAL HEAD PRODUCED BY THE PUMP MEASURED IN FEET STATIC HEAD STATIC SUCTION HEAD
NEGATIVE SUCTION HEAD MAXIMUM THEORETICAL SUCTION LIFT 34 FEET MAXIMUM PRACTICAL SUCTION LIFT 15 25 FEET
TOTAL HEAD PRODUCED BY THE PUMP MEASURED IN FEET STATIC HEAD STATIC SUCTION HEAD STATIC DISCHARGE HEAD DYNAMIC HEAD IMPACTS FRICTION LOSS VELOCITY HEAD DYNAMIC HEAD DYNAMIC DISCHARGE HEAD DYNAMIC SUCTION HEAD
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
SUCTION LIFT CONDITION
FLOODED SUCTION CONDITION
THE HORSEPOWER REQUIRED TO DRIVE THE PUMP AKA BRAKE HORSEPOWER EFFICIENCY MEASURES PUMP S ABILITY TO CONVERT PUMP HP TO WATER HP PUMP EFFICIENCY = MECHANICAL EFFICIENCY
PHp = WHp EFF PUMP WHp = Q (gpm) x TDH (feet) 3,960 PHp = Q (gpm) x TDH (feet) 3,960 x EFF PUMP
MOTOR EFFICIENCY = ELECTRICAL EFFICIENCY
MHp = PHp EFF MOTOR PHp = Q (gpm) x TDH (feet) 3,960 x EFF PUMP MHp = Q (gpm) x TDH (feet) 3,960 x EFF PUMP x EFF MOTOR
MEASURED IN WATTS OR KILOWATTS TOTAL CONSUMPTION IS BASED ON OPERATING TIME IN KILOWATT-HOURS (KWH) Hp =.746 KW (KILOWATTS) COST = Hp x.746 KW/Hp x OP HRS x CENTS/KWH
EFF = EFF PUMP x EFF MOTOR EFF = WHp x PHp = WHp PHp MHp MHp ELEC MHp EFF M PHp EFF P WHp