May I know, what is the IEEE Standard used to calculate the heat load from electrical equipment (equipment in electric substation)?
As I go through IEEE Standard 241 that I can found online, I cannot find any calculation inside.
Appreciate if anyone can advise me on this.
Thank you.
Dear Artisi,
Noted and thank you for your advise.
Dear LittleInch,
Appreciate of your explanation. From you explanation, I know that we can install a control valve at downstream of pump B to reduce the flow, and prevent pump B to go dry (if possible).
In this situation (if the pump not...
Dear Artisi,
For your information, for this thread i really dont have any installation sketch or much information. I am just curious of what might happen if incoming supply cannot meet the pump demand (suddenly).
Thank you for your willingness to help. I will try to input more detail, sketch...
When incoming supply is not enough, will pressure drop also?
If NPSHa drop to a certain level (let's say lower than NPSHr of pump), then cavitation will happen. Is my understanding right?
Sorry, I know I am lacking in knowledge. Sorry.
I never say is your fault or others. Please dont assume in your own way. I am not too lazy as I got many things to do also like everyone, I just want to ask and in the same time do some research. I dont know much about engineering. But I know there are many difference situations in difference...
"the pump will continue to operate until such times as the liquid in the tank and the inflow are less than the pump output capability, the pump will STOP pumping. " But if no control system to the pump, it will stop automatic when the inflow is less than the pump capability?
So, if incoming...
Artisi,
Yes, I agree I am lazy to do research on engtips as other situation might not same with mine. You have mentioned twice. I thought this is a forum to post the question and seem like engtips does not have the rule of posting the question.
However, thank you for your reminder. Thank you.
I...
"If you have insufficient fluid coming into the pump inlet, how can you recirculate flow back to the inlet to make up the short-fall of flow."
Is this statement true? As per my understanding, flow can be controlled by restrict orifice. And whenever there is a separate line (from one line to two...
System curve represents the friction loss along the pipeline and it is constant if the system does not change. Am I right?
If the incoming supply cannot meet the demand of the pump, can i still refer to the pump curve and evaluate all the parameter at the point where the capacity of the incoming...
The above situation is what I image. What I want to know is the situation might happen when not enough liquid to be pump. Maybe I should write the incoming supply cannot meet the demand of pump (as I don't know what is the better term to be used). In this case, should I draw the installation...
"pump B will then go off prime and cease pumping", is this mean all pump have this feature (although I am not installing any instrument or control system)?
Or what is mean by this sentence (maybe I get it wrong)?
Thank you.
I am not sure if these relation of parameters (flow rate, head, NPSHr) is still application when the incoming supply cannot meet the demand of pump. I am not sure if pump curve is still valid in this situation.
I apologize as I do not know much. I haven't see thing much and I am lacking of...
"Cavitation will happen at Pump B (but it is not due to insufficient NPSHa)? Pump B will still run at same speed (not using variable speed drive), the capacity will decrease (due to insufficient water)?"
These are the questions and I thought it is obviously the questions?
Ok, let me explain...
Thank you for your response.
I apologize for my not professional question.
For your information, this spill back system has been design to allow some of the liquid spill back to the suction of pump when not enough liquid from suction source. As I am not the one to design this system, I am not...
Thank you for spending your time to response to my thread.
I appreciate if you can treat me as a student. I don't have much experience as I have less than 1 year working experience in Engineering field. I don't know what is the "more detail" that I need to share. I apologize if I am asking...
Kindly refer to the image uploaded.
May I know, what is the percentage range of the capacity that can be spilled back to the suction of the pump through the recirculate line (restrict orifice located at the recirculate line)?
Can i maximize the capacity of spill back by installing a flow...
Let's say a centrifugal pump is designed to operate at a flow rate of 10 m3/hr with head of 50 m.
If the liquid from the suction is not enough to be pumped (only 5 m3/hr liquid is available):
1) Will the pump still function at the designed rpm?
2) Will the pump capacity still remain as 10...
Is the main reason that suction pressure is lower than atmospheric pressure, is because the liquid level (Static suction level) is lower than the centerline of the pump?
If this situation happen, the most suitable pump to be used is self-priming pump?
Appreciated if anyone can advice and...
By referring to you statement, "when we refer to inlet/outlet pressure, we implicitly refer to "total" pressure" and "Total Pressure = Static Pressure + Dynamic Pressure", is the dynamic pressure being considered when calculating the suction pressure of a pump?
Suction pressure = suction...
Is the suction pressure of a pump, the static pressure, dynamic pressure , hydrostatic pressure or total pressure at the inlet of pump? Or I cannot relate the suction pressure to those pressure?
Suction pressure = suction surface pressure + static suction pressure - suction friction pressure...
