Questions tagged [pumps]

For questions about the design, classification and working principle of pumps. A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action.

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will a hydraulic gear pump be capable of the same pressure at all speeds?

I'm trying to build a hydraulic power unit with a 5 horsepower electric motor, gear pump and tank. The flow requirement for the system is 1.7 gallons per minute. The pressure requirement is 3000 psi. ...
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Calculate hydraulic cylinder and pump forces on backhoe

I have a field find mini backhoe from a shut down manufacturer. The product is a beaver Pro QT50 backhoe used for small tractors, atvs, and pick up trucks. Unfortunately, there's no documentation on ...
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Choosing the right pipes for a combination of peristaltic and circulation pump

I would like to circulate the water within an aquarium that contains around 30l water with a circulation pump and an active chiller that contains R134a cooling fluid. New water shall be sucked with a ...
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2 answers
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How to connect a 1/4 NPT pressure gauge to a schrader valve while being airtight

I need to attach this pressure gauge - https://www.amazon.co.uk/gp/product/B07CXM3ZGT/ref=ask_ql_qh_dp_hza - to a schrader valve with a pipe to measure the pressure. The valve has a 1/4 NPT thread. I ...
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Is there a type of rotary positive displacement pump that can pump hot exhaust gases?

Is there a type of rotary positive displacement pump that can pump hot exhaust gases (~900°C), that is, not requiring lubrication that would otherwise be burnt off?
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Risk of operating hydraulic gear pumps below minimum speed

I'm looking at Marzocchi micro gear pumps, particularly the 2.00 model. Speed range is 800-200 rpm (although page 20 shows flow for 100-3500), but in my application I plan on using a bi-directional ...
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Venturi Injector

I have a venturi injector attached to a pump. I am using this injector to draw air naturally into the system when water is the prime fluid. However, I am seeing the discharge pressure of the pump is ...
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1 answer
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How do I build or buy a reversible, high capacity pump?

In my application, I need a small water pump (a typical 'batch' might be 500 ml) that can pump in both directions. I need to pump this much volume in 20 seconds or so. It's small-scale, very low-...
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Can a hydraulic vane motor have a specific rotational output?

If a vane motor/pump was used in a hydraulic circuit, could the rotation of the vane pump be controlled for slight movement in angles? I imagine this would would require a feedback controller, with ...
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What is the lowest energy solution for emptying a drip irrigation water collector : a mono-stable solenoid valve or a bistable coupled to a pump?

I have a water collector I want to empty everyday for drip irrigation. It is controlled by a micro-controller. I have identified three solutions: Use a bi-stable electro-valve and a pump: advantage ...
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Relief valve for "semi-closed" loop system (non-engineer warning :-)

My excuses in advance for the probably-bad wording of the question, I'm just an hobbyist without much knowledge in engineering. To the point I can't google for information on my problem since I don't ...
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Why does my coffee machine's water reservoir have two connections to the pump?

I'm trying to bypass the water reservoir and plug my Ninja CP307 directly into a reverse osmosis system.. This is a picture of a disassembled Ninja CP307 coffee maker. But, when I opened up the ...
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1 answer
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Can I use a standard HVAC rotary vane vacuum pump to draw a vacuum on a sealed chamber?

Background I have a beginner question concerning rotary vane vacuum pumps like this one: VIVOHOME 110V 1/3 HP 4CFM Single Stage Rotary Vane Air Vacuum Pump Here are the pump specifications: Voltage: ...
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Reusing Old Wells to Desalinate Water with Geothermal

Could we reuse expired wells in places like Huntington beach California, to desalinate water? I found the following chart online which suggests that some deeper wells could have temperatures high ...
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Is there a positive displacement pump that experiences only rolling resistance?

Is there a positive displacement pump that experiences only rolling resistance? One with no sliding friction and diaphragm stretching?
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How to determine pump input/output pressure?

I wanna create iterative simulation of some fluids system. In this system i have multiple connected objects. For each object i calculate input and output pressure and then calculate transfered amount ...
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1 answer
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Influence of bigger air-pumps pulling effect over small pumps

When there are two air-circulation pumps (one powerful than the other) connected in series (as shown in the figure), how would the bigger pump affect the smaller pump? Should the smaller pump be ...
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Extrapolating compressor curves for varying pump speeds

I'm currently working on modeling a vacuum system in which a pump is present. the pump is driven at a varying speed $\omega$. The manufacturer has only given the characteristic curve at a single speed ...
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2 answers
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How to calculate a circulation pump size?

I would like to get some help regarding sizing a pump. I'm working on a project in which we want to select a pump to generate a flow through a rectangular channel whose two ends (the inlet and outlet) ...
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In a high pressure water pump what component or design parameter increases pressure output, let's say from 200 atm o 2000 atm?

type of flow? length or diameter of the plunger piston?, or weight of the piston and crankshaft and torque or HP to move it?, or RPM. direct drive pumps used in waterjet cutting use a slim plunger ...
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3 votes
2 answers
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How to measure a screw pump spindle?

My boss ordered a screw pump driving spindle from an alternative maker. That spindle, as expected, cannot turn with the two idle spindles inside the housing. Now he is asking for the spindle ...
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Is NPSHr dependant on temperature?

I know that net positive suction head available depends on temperature since viscosity, density and vapour pressure depends on temperature but how about NPSHr? We know that the vapour pressure depends ...
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Selecting a water pump for low flow and 1 Bar pressure

I am designing a small automatic drip irrigation system. There will be about 10-15 drippers. Flow through the system will be about 1 l/minute, but this may change if expanding or reducing the system. ...
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2 answers
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Pumps' geometric similarity

Given two pumps that are similar : $H_1=70-1.41x10^{-3}Q_1^2$ $H_2=100-1.1x10^{-3}Q_2^2$ Find the geometric scale : $\frac{D1}{D2}= ?$ I am also given maximum efficiency = 1. I tried solving but I got ...
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Will decreasing a pump's flow rate decrease the NPSHR?

I have a small open hydraulic system and I simply need to circulate hot (85C) water from the bottom of a reservoir back into the top at ~4GPM. At its lowest point the system has only 3ft of static ...
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What is this mechanical pump called?

I am unable to find it again but I once heard of a type of air pump that involved a pair of offset archimedes screws inside a cylinder. The point of the device was that as the screws would turn ...
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1 vote
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What kind of pump to choose for a weight-based rain gauge?

I'm designing a rain gauge which uses accurate electronic scales to measure weight of water (and therefore volume) that has entered the sump. Ideally the system will not require any manual ...
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Does any know what kind of pump "Colossus" used for saving the Notre Dame Cathedral?

Does any know what kind of water pump the French Firefighting Robot Colossus used to Help Save Burning Notre Dame Cathedral? What kind of water pumps do fire fighting vehicle use or fire fighting ...
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1 answer
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What is the difference between a single-stage pump and a centrifugal pump?

Here is the small $12 \; V$ pump that I am looking at. The manufacturer called the product as DC brushless centrifugal circulation small water pump but under its description it mentions that it is a ...
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1 answer
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How does the efficiency curve of a well pump shift with speed?

Well pump manufacturers publish "efficiency curves" for well pumps, such as this one (the curve that is most sharply convex down, whose Y axis is read from the "% EFF" scale on the ...
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2 votes
1 answer
561 views

Can you help me to interpret technical drawings?

I'm trying to find out the angle/ length of the oblique line, or the solid angle of the conic part. This is what I've tried so far: According to the pythagorus theorem the length of the line is equal ...
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Small water pump powered by wind turbine : what type?

I need to aerate a small pond in my garden. I would like to build an autonomous system with a small water pump. The power would come from a small vertical wind turbine I will build. Since my pond is ...
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Pump system with dynamic head

Given: A pump system is defined with dynamic head of 46 feet. The height between the static pressure gauge and the surface of the water is 9 feet. Assumptions: Friction losses between the tank and ...
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Calculating the load torque on a turbine pump

How is the load torque on a turbine pump handled. Generally, with motors, there is a load attached to the shaft which resists the output torque of the motor however, with a pump increasing the flow ...
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1 vote
1 answer
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Low maintenance device to trade flow rate for lift height?

Is there a compact device which can trade flow rate for lift height without too many moving parts? My particular application is a 10 meter deep and 10 centimeter wide well with shallow water level, ...
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Using a Threaded Rod and Internally Threaded Tube as a Piston Pump

Im looking for a low cost, high pressure pump with good flow/pressure control for an espresso machine (a lot to ask, I know). My first thought was using a screw-driven piston. This will work, but Im ...
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1 answer
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What does the author mean? Turbomachinery - Reaction

I am reading a book of Fundamental Energy Systems. The author describes the rate of change in head for a turbomachine as: $$ \frac{1}{2}[(V_1^2-V_2^2)+(U_1^2-U_2^2)+(V_{R2}^2-V_{R1}^2)] = H =U_1V_{u1} ...
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Does air flow rate of an air pump imply the same rate when using it to pump water via air pressure?

I want to build a machine that pumps liquids (roughly density of water) out of an enclosed cannister. The cannister has for one inlet for air at the very top and has an outlet (near the top as well) ...
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Hydraulic energy recovery for high-pressure, low flow (non-steady state) conditions

What would be the best way to implement hydraulic energy recovery while de-pressurizing a pressurized volume of silicone oil initially at 1500 bar. Can a piston pump be concievably repurposed as a ...
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2 votes
1 answer
166 views

Running a hydraulic pump below minimum RPM

If I had a pressure compensated, hydraulic piston pump, how might the performance look in terms of pressure if I were only looking in the regime of 0 RPM and the minimum ratedRPM? I.E If a pump was ...
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1 answer
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Quantifying the reaction force on fixed tubing connected to a peristaltic pump

I am not sure how I should consider the forces due to hydrostatic pressure when calculating the reaction force due to a fluid being pumped through fixed tubing with a peristaltic pump that I am using ...
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1 answer
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How could an absorbent material be emptied?

I have been thinking about this for quite some time: Given a foam or other absorbent material saturated with a solvent, how could you draw all the solvent to the top of the foam (basically how could ...
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How energy intensive is creating artificial islands in the IJsselmeer?

The City of Amsterdam is building a series of artificial islands for new housing. One of them is Centrumeiland. Its size is 13 ha. (130,000 m2). Its creation requires 800,000 m3 of sand (Source), i.e. ...
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Possible to suck water through manual bilge pump using a transfer pump?

I dug a shallow well (12' deep) on a remote off-grid Florida Property I own. The well is a simple 1-1/4 PVC Sand Point well I hammered in the ground. I then used a rubber coupler to attach a cheap ...
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Volumetric oil pump efficiency goes up when viscosity goes down?? Strange behaviour

Riddle me this : we are driving an external gear pump (this kind) at a fixed RPM. At start, when the oil temperature is low (and viscosity high), the volumetric flow is much less than when the oil ...
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How is the ideal Euler line on a pump curve derived?

This website provides Euler’s equations for turbomachinery and solves a sample problem using velocity triangles. The problem prompt only provides the speed of the pump and the geometry of the pump and ...
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Pump Power Question

Consider I have a pump sized to deliver 200 gpm of a fluid with a specific gravity of 0.7 and a total differential head of 60 ft of water. What is the hydraulic horse power? To calculate the hydraulic ...
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How to measure absolute zero vacuum in pumps

In a vacuum pump, does the inlet pressure measure closer to 30 inHG? The following is a pure water pump, a 100w 8 meter regenerative turbine pump. Not a vacuum pump. Maybe the reason it couldnt get ...
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Pipe with change of section

I'm a novice in mechanical engineering and I'm having some troubles to find a pipe that change from one section to other. In this case I want to connect a circle section to a rectangular section. I ...
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1 answer
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Pump Terminology: Suction Piping vs Suction Waterway

Karassik and McGuire state in their 2012 book, [1] p. 415, The available energy that can be utilized to get the liquid through the suction piping and suction waterway of the pump into the impeller is ...
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