# which is the correct formula for net pump discharge pressure

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• ### HOW TO CALCULATE PRESSURE ANYWHERE IN A PUMP

2008-4-20 · CALCULATE THE PRESSURE HEAD ANYWHERE ON THE DISCHARGE SIDE OF THE PUMP Equation [4] is the result of an energy balance between points 1 and 2. The same process of making an energy balance can be applied between any two points for example points 1 and X (see Figure 3). We can do an energy balance between points 1

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• ### NPSH Calculation: A Step-by-Step Guide - Pumps &

2018-7-11 · The net positive suction head is the total suction head in feet of liquid (or meters), less the vapor pressure (in feet or meters) of the liquid being pumped. Think of head as an energy level and not as a force-like pressure.

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• ### Fire Pumping Calculations: Every Pump Operator's

2012-10-1 · If the friction loss in 100 feet of 2½-inch hose is 15 psi, the pressure in the hoselay would decrease by 15 psi for every 100-foot length connected, but the pump discharge pressure will need to ...

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• ### Annual Pump Test - David's Fire

2020-12-30 · If you cannot find a location where a 10' lift is achievable there is a formula in the reference materials that can be used to correct gauge readings to accommodate you. Calculations will also be required to determine 'the corrected net pump pressure.'

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• ### Calculate NPSHa for a Closed & Pressurized System |

2018-10-31 · Absolute pressure equals gage pressure plus atmospheric pressure, therefore 120 + 14.7 = 134.7. We will round off to 135 psia. Notice that while the suction pressure is almost 120 psig, the result for the NPSHa calculation will be less than 7 feet. This is one reason I instruct all of my pump school students to always calculate the NPSHa.

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• ### How to find pump size and pump head calculation

2015-6-11 · The net positive suction head available (NPSHa) is the difference between the absolute pressure at the pump suction and the vapour pressure of the pumped liquid at the pumping temperature. It is important because for the pump to operate properly, the pressure at the pump suction must exceed the vapour pressure for the pumped fluid to remain ...

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• ### Back to Basics Pump Sizing - AIChE

2016-12-2 · Discharge Suction Impeller Eye Impeller pFigure 1. In a centrifugal pump, a rotating impeller imparts energy to the liquid moving through the pump. Outlet Inlet Low-Pressure Fluid High-Pressure Fluid Fluid Carried Between Teeth and Case pFigure 2. A gear pump is a type of positive-displacement pump …

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• ### TUTORIAL CENTRIFUGAL PUMP SYSTEMS

2015-5-1 · The term pressure loss or pressure drop is often used, this refers to the decrease in pressure in the system due to friction. In a pipe or tube that is at the same level, your garden hose for example, the pressure is high at the tap and zero at the hose outlet, this decrease in pressure is due to friction and is the pressure loss.

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• ### Selection of pump - SlideShare

2012-3-13 · Pump selection: based on the fluid characteristics, turn-down ratio, discharge pressure and system requirements, availability of space, lay-out, energy and pump costs, code requirements, and the materials used in the construction. Reciprocating pumps (plunger or diaphragm type) for liquid chemical metering and injection applications (small ...

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• ### 5 Common Questions About Sump Pump Discharges

2019-7-29 · 5. How long can a sump pump discharge pipe be? As long as your property has a downward slope from the point of discharge to the end of the pipe location, it can be any length that you want, subject to engineering requirements for size and drain capacities, etc. Again, in our area, freezing becomes a big consideration. Keep in mind that the ...

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• ### Net Oil Pressure Part III – Oil Pressure - 2012-02 - SP ...

The net oil pressure is 24 PSIG - 7 PSIG, or 17 PSI. Assume a case where the compressor crankcase (suction) pressure gage reads 18 INCHES HG vacuum (-8.84 PSIG) and the oil pressure gage reads 13 PSIG. The net oil pressure is 13 PSIG - (-8.84 PSIG), or 21.84 PSI

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• ### Pumps 101: Operation, Maintenance and Monitoring Basics

2012-8-31 · pressure, discharge pressure, flow, pump speed, and power. At a minimum, suction and discharge pressure are essential for determining the Total Dynamic Head (TDH) of the pump and the available Net Positive Suction Head (NPSHa). Understanding the

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• ### Flow rate [m h] Total head [m] - Fristam

2019-6-20 · NPSH is the abbreviation for Net Positive Suction Head Besides the flow rate Q and the pump head H, the NPSH value is one of the most important characteristic parameter of a centrifugal pump. The NPSH value of the pump depends on the design and speed of the pump. The higher the speed of the pump, the higher the NPSH value will be.

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• ### Annual Pump Test - David's Fire

2020-12-30 · If you cannot find a location where a 10' lift is achievable there is a formula in the reference materials that can be used to correct gauge readings to accommodate you. Calculations will also be required to determine 'the corrected net pump pressure.'

Get Price
• ### TUTORIAL CENTRIFUGAL PUMP SYSTEMS

2015-5-1 · The term pressure loss or pressure drop is often used, this refers to the decrease in pressure in the system due to friction. In a pipe or tube that is at the same level, your garden hose for example, the pressure is high at the tap and zero at the hose outlet, this decrease in pressure is due to friction and is the pressure loss.

Get Price
• ### 5 Common Questions About Sump Pump Discharges

2019-7-29 · 5. How long can a sump pump discharge pipe be? As long as your property has a downward slope from the point of discharge to the end of the pipe location, it can be any length that you want, subject to engineering requirements for size and drain capacities, etc. Again, in our area, freezing becomes a big consideration. Keep in mind that the ...

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• ### 16 Steps to Proper Boiler-Feed-Pump Selection |

2017-1-11 · 6. Calculate base head for the feed pump. When calculating total dynamic head for all centrifugal pumps, consider all of the influencing factors on both the suction side and the discharge side of the pump. Use the following formula: base head in feet = maximum boiler operating pressure × 2.31 × 1.03 liquid specific gravity 7.

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• ### Am I calculating the power required and power out

2021-4-5 · Multiply this by the motor efficiency to get the net power being delivered to the pump mechanism. Ordinary electric motors are about 85% to 90% efficient. Equate this to the mass flow rate times the pressure developed by the pump (this is the 'hydraulic horsepower').

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• ### pump suction gauge is ZERO,DISCHARGE 40 PSIG. -

2016-1-26 · I now assume that the inlet gauge is a pressure gauge, is this correct? If it is a pressure gauge, then if the inlet is at negative pressure the gauge will read zero. You need to fit a compound or a vacuum gauge to establish what condition the inlet to the pump is operating under. It is a capital mistake to theorise before one has data.

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• ### Selection of pump - SlideShare

2012-3-13 · Pump selection: based on the fluid characteristics, turn-down ratio, discharge pressure and system requirements, availability of space, lay-out, energy and pump costs, code requirements, and the materials used in the construction. Reciprocating pumps (plunger or diaphragm type) for liquid chemical metering and injection applications (small ...

Get Price
• ### Net Oil Pressure Part III – Oil Pressure - 2012-02 - SP ...

The net oil pressure is 24 PSIG - 7 PSIG, or 17 PSI. Assume a case where the compressor crankcase (suction) pressure gage reads 18 INCHES HG vacuum (-8.84 PSIG) and the oil pressure gage reads 13 PSIG. The net oil pressure is 13 PSIG - (-8.84 PSIG), or 21.84 PSI

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• ### Determining Useful Oil Pressure and Discharge

2018-4-30 · When dealing with refrigeration or air conditioning compressors that employ an oil pump, many service technicians confuse net oil pressure with oil pump discharge pressure. However, it is of utmost importance to understand the difference between these two pressures when servicing compressors with oil pumps. Many larger compressors in the refrigeration and …

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• ### Fire Pumping Calculations: Every Pump Operator's

2012-10-1 · If the friction loss in 100 feet of 2½-inch hose is 15 psi, the pressure in the hoselay would decrease by 15 psi for every 100-foot length connected, but the pump discharge pressure …

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• ### Pump Design Equations Formulas Calculator Water

flow rate or discharge: H = total head: n = pump efficiency: BHP = brake horsepower: NPSH = net positive suction head: V = velocity of fluid or liquid: p = impeller inlet pressure: p v = vapor pressure of fluid or liquid: SW = specific weight of fluid or liquid: g = acceleration of gravity

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• ### Net Positive Suction Head for Centrifugal Pumps -

2019-8-13 · The formula for calculating NPSHA, therefore, becomes: NPSHA = h1 + hss – hf – hvp. Where: h1 is the absolute pressure over the liquid in feet; hf is the friction in the suction line in feet; hss is the static head in feet – this is negative if there is a suction lift; hvp is the vapor pressure of the liquid at the pump in feet

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• ### How to Read a Positive Displacement Pump Curve -

2020-1-15 · As discharge pressure increases, keeping viscosity constant, more fluid slips from the discharge side to the suction side of the pump, so the pump must spin at a higher RPM to maintain output. In Fig. 2, a positive displacement pump curve shows the influence of viscosity on slip with a correction chart.

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• ### Friction Loss Calculator

2019-12-3 · Instructions on calculating pump discharge pressure Learn pump pressure management combining elevation change, hose friction loss & appliance friction loss. Pump and plumbing diagram Visual tool to map a fire engine's pump and plumbing. Follow the water to learn how the pump, valves and plumbig work together to deliver water to the fire.

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• ### Rules to Follow to Avoid Pump Problems | Valin

2014-8-5 · NPSHA or Net Positive Suction Head Available is based on the design of the system around the pump inlet. The average pressure (in psia or feet of head) is measured at the inlet port during operation, minus the vapor pressure of the liquid at operating temperature. It indicates the amount of useful pressure energy available to fill the pump.

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• ### (PDF) Equations correct centrifugal pump curves for

At pump best efficiency point (BEP), the boosting pressure decreases 30–40% when oil viscosity increases from 10 cp to 100 cp. ESP becomes ineffective when oil viscosity is higher than 200 cp.

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• ### Question - Engineering Thermodynamics.docx -

Question No. 12: (a) State the difference between extensive, intensive and specific properties of a thermodynamic system. (b) Air at 20°C and 7 bar is contained in a rigid tank of 0.57 m 3 volume capacity. The tank is provided with a valve that opens at a pressure of 8.5 bar and remains open until the pressure drops to 8.15 bar. Determine: (a) Air temperature just before the valve opens …

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• ### Determining Useful Oil Pressure and Discharge

2018-4-30 · When dealing with refrigeration or air conditioning compressors that employ an oil pump, many service technicians confuse net oil pressure with oil pump discharge pressure. However, it is of utmost importance to understand the difference between these two pressures when servicing compressors with oil pumps. Many larger compressors in the refrigeration and air conditioning field …

Get Price
• ### Manual for the Design of Pipe Systems and Pumps

2021-4-14 · 3. The pump type chosen must correspond to product viscosity, product density, temperature, system pressure, material of the pump, shearing tendency of the product etc. 4. The pump size must conform to the flow rate, pressure, speed, suction conditons etc. As a manufacturer and supplier of centrifugal pumps and positive displacement pumps we

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• ### EngineCompanyOperationssection 5 Final-1

2018-7-28 · scene and the necessity of being able to quickly compute the correct pump discharge pressure for each situation, a practical approach to hydraulics is necessary. The information contained in this section is satisfactory for most fireground situations. 5.2.2 The scope of th is section is limited to essential hydraulic principles a

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• ### NPSH - Net Positive Suction Head

2021-5-7 · The vapor pressure in a fluid depends on the temperature. Water, our most common fluid, starts boiling at 20 o C if the absolute pressure is 2.3 kN/m 2. For an absolute pressure of 47.5 kN/m 2 the water starts boiling at 80 o C. At an absolute pressure of 101.3 kN/m 2 (normal atmosphere) the boiling starts at 100 o C. Net Positive Suction Head ...

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• ### Understanding Gauge and Absolute Pressures in

2019-10-15 · A pump’s NPSHa value is crucially important to understanding if the pump is correct for the job at hand. NPSHa, or Net Positive Suction Head Available, is crucial to avoiding cavitation and other inefficiencies. It is determined by subtracting the liquid vapor pressure from the suction pressure: NPSHa = Suction Pressure – Liquid Vapor Pressure

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• ### Pump Selection Guide - All Pumps Sales & Service -

NET POSITIVE SUCTION HEAD. Net Positive Suction Head (NPSH) has two definitions: NPSH Available (NPSH A): the absolute pressure at the suction port of the pump. NPSH Required (NPSH R): The minimum pressure required at the suction port of the pump to prevent it from cavitating. Use our Friction Loss Calculator to calculate your total head loss.

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• ### Back to Basics Pump Sizing - AIChE

2016-12-2 · Discharge Suction Impeller Eye Impeller pFigure 1. In a centrifugal pump, a rotating impeller imparts energy to the liquid moving through the pump. Outlet Inlet Low-Pressure Fluid High-Pressure Fluid Fluid Carried Between Teeth and Case pFigure 2. A gear pump is a type of positive-displacement pump …

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• ### Pump calculations - The Engineering Mindset

2017-9-11 · In this article we learn how to perform pump calculations in both imperial and metric units to assess pumping performance following the change of flow rate, pump speed, head pressure and power. These formulas are common practice rules of thumb and provide theoretical values to which actual values will likely differ. YouTube video tutorial at […]

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• ### Mike Slusher’s Pump Test

2010-9-17 · In testing the pump there are three variable factors, the change in one factor will cause change in at least one of the other factors. The three variables are pump speed, net pump pressure, and pump discharge rate. For example; any change to engine speed changes pump speed. Any change to hose layout or valve position changes pump pressure.

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• ### (PDF) Procedure for Conducting Pumping Tests

The pump and power unit should be capable of ope rating continuously at a constant discharge for a period of at least a few days. There are several factors to be considered when d etermining the ...

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