The thing with fire fighting pump set is that they are basically meant to work at one point only. This means that such a pump has only one point of flow and head. This can be described as a hydraulic condition. It is also referred to as BEP (Best Efficiency Point) as well as the best operating point. It may have a published set of curves. However, as experts would tell you, this is merely a commercial compromise. For most end-users, the process of getting a pump built and designed to suit their special hydraulic conditions would be really expensive.
Paying attention to the published curves of the pump
Even if you have bought Kirloskar water pumps India this is something that you must do. The pump performance covers of the makers are based on clear water. The approximate mark here is 65 F. This is unless something else has been stated by the makers. You can be sure that they would not be corrected with respect to fluid viscosity. Even when they have started a horsepower it may or may not be corrected for specific viscosity and gravity.
If the published pump curve stops it is for some good reason
If centrifugal pump distributors have published a particular pump curve and if it stops at some point of the head and flow there is definitely a good reason for the same. You should never operate your pump at the end of the curve. If the pump was capable of producing a better performance the makers would have extended the curve themselves. If you operate it till the end of the performance curve or near you can be sure you would be facing issues in the future.
Pumps can be stupid
As the best water pump dealers in Thane would tell you, these pumps can be rather stupid. You need to understand that a centrifugal pump is basically a machine. It has a certain set of fluid properties, operating speed, and impeller geometry. It is because of these characteristics that it would react a certain way to the system that has been installed. The flow and head point of the pump will be a crossing point of its system curve and performance curve. The system curve would basically dictate where these pumps would operate.
You have to understand the system curve
The system curve can be said to be representative of all the friction as well as the pressure and static head that has been baked into the same.
A fire-fighting pump set will also have a velocity head. However, under normal circumstances, it would be so small that you would not really be concerned about it.
Your pump would never suck fluids. This is a misunderstanding that is surprisingly common. You need to understand that there has to be another energy source that would be needed in order for the liquid to get to the pump. Normally, the best examples of such sources of energy are atmospheric pressure and gravity.