Determining Pump Head

[rockman7892]

We have a pump here at our plant that pumps cement from a Mill up to the top of a silo. Lately we have been overheating the motor on this pump and I am trying to determine if for some reason the pump may be working too hard.

Now I know the basics of pumps and that the static head is related to the height of the discharge pipe above the pump suction resoivar. I also know that from a static head you can look at a pump curve and determine the CFM and HP of that pump for that given static head.

My question is regarding the static head distance in feet and how it relates to a pressure. In other words, lets say I have a static head of 100ft, how do I represent this as a head pressure since this is what pump curves have listed?

Also if using something to represent the head pressure do you need a pressure gauge down at the pump or up at the discharge of the pipe? If I wanted to watch the head pressure in this pipe to use it as a variable on the pump curve to look at flow rate and HP then where would be a good place to locate this pressure gauge?

 

[rockman7892]

If we feel that the problem may be coming from overloading the pump with material, witll a change in the pressure reading on the inlet of the pump indicate an overloading condition? In other words is we see a large pressure increase at the inlet of the pump will this be an indication of overloading?

 

[Waramanga]

How big is the pump motor in kW? Is it three phase? Motor amps will give you a very good indication of overload. I would suggest logging motor amps to find out exactly when it happens. Why are you cooking motors? where are the motor overloads etc if they are set right you can avoid these ok especially if they are manual reset.