Pump Header 2

[rgb07]

Can anyone help me?
I am testing a piston water pump. The input of the pump I connect to the water tank. The output of the pump I have fitted a water pressure gauge and a gate valve. If I shut the gate valve I have a reading showing on the pressure gauge (PSI/Bar). I want to know how I can work out the formula this pump can pump how many feet head of water without setting up a real test.

 

[iceland1]

the head of liquid is given by: pressure / (density x gravity)

 

[rgb07]

I still do not understand the formula,
Assume the gauge pressure reading is 50psi
Pa = atmospheric pressure apx. 14.7 psi
Pvp is the vapor pressure of the water at its temperature, which is about 0.5 psi for normal ambient temperatures
The density of water = 62.4 lbs/ft3

How can I apply this to the formula? If possible I need help for more explanation.

 

[Artisi]

The head generated is approx. psi x 2.3 = ft head

 

[quark]

I am confused by the original post.

If I shut the gate valve I have a reading showing on the pressure gauge

Why to shut the valve off? Do you intend to know the head in meters when the pressure is known in psi or do you want to know how much head the pump develops (without using the gauge)? For the first one, you already have the answer. For the second one, check the pipe system resistance.

 

[rgb07]

I shunt the valve off because i have not connect to any pipe for testing,i have no back presure go into the output of the pump, i just want to know if i have a reading of the output of the pump, how many feet head of water i can reach

 

[katmar]

It is not a good idea to run a piston pump into a closed header. Hopefully your pump has an internal relief valve and has not been damaged. The pressure you are reading is then the set pressure on the relief valve. Converting a pressure to a head has already been properly dealt with above by Artisi.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[dcasto]

A piston pump will put up head (pressure) until it breaks, either the fluid end piping/cylinder or the plunger/crankshaft.

 

[rgb07]

Thanks for you all to answer my question, but the question i ask your guys still not get the point what i need. all i want to know is the calculation formala,( step by step) and or a method to test a small unknow specification pistion pump without connecting a real long pipe for experiment test (HOW MANY FEET HEAD OF WATER I CAN REACH), i understand the calculation is not 100% accuate, but at least i have some reference to base on, The consideration of overload the pump and damage are exelusive

 

[rzrbk]

rgb07,

The above posts are correct.

Exclusive of damage and overload, there is no maximum pressure (head) for a piston type pump.

If you increase the discharge pressure of this type pump, it will literally continue pumping until you have a mechanical failure, or your motor runs out of torque.

 

[rgb07]

rzrbk good answer. i need to know before the motor runs out of torgue, how many feet head of water i can reach

 

[BigInch]

Maximum head is at shutoff, so that's at zero flow, so that information isn't real useful if you need to be flowing at some given rate. You need to know how many feet of head you can develop at your required flowrate. Get that from the pump curve.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[dcasto]

OK, you have another limit, your motor. Read the maximum HP of the motor. Multiply the HP by 1538, then divide by the gallons/minute the pump is plungered and at a specified RPM. That will be the maximum pressure you will be able to run the pump, unless that pressure exceeds the working pressure of the pump or piping.

PSI = HP * 1538 / GPM

 

[Golestan]

Hi Guys,
The out put (flow rate) of a piston pump actualy depends on the pump design. Piston travel, diameter, rpm, number of cylinders. At a given rpm, the flow is constant. The motor horse power should be sufficient to push the fluid to where it is directed.