How to Model Configurable Booster Pump/ Valve in MiTS

Residual pressure is the pressure remaining in a water distribution system when water is flowing, and it’s crucial for ensuring adequate water supply and preventing system failures. Maintaining sufficient residual pressure is vital for proper operation of plumbing fixtures, fire hydrants, and other water-dependent systems, especially during peak usage or fire emergencies.

What is a Configurable Booster Pump/ Valve? #

It is a type of pump/ valve that only turns ON/OFF based on specific conditions. For example, a booster pump stays OFF during normal operations (peak demand) but activates (ON) during fire emergencies (hydrant demand) to boost pressure at hydrants.

Scenario: Peak Flow OK, Fire Flow Fail (Need to Add Pump) #

1. In a typical water reticulation design, the residual pressure within the domestic pipeline may be adequate to meet daily water demand without any pump. 
2. But during fire breakout, residual pressure may drop and fails to meet pressure required for effective firefighting operations. 
3. In this situation, a booster pump must be installed specifically for the hydrant system to elevate the pressure and ensure compliance with fire flow requirements.

How to Model Configurable Booster Pump/ Valve #

When you insert a pump/ valve in MiTS it will be analysed in both peak and fire calculation (That is if you insert hydrant in the model). To model the configurable booster pump, we can create two separate project files for peak flow and fire flow analysis.

Situation 1: External Water Reticulation System (From Supply Main) #

Sample Project File (1): Daily domestic water demand (No Pump – CLOSE)

Sample Project File (2): Hydrant system demand (Add Pump – OPEN)

 

Workflow:

1. Run Analysis for both Peak Flow and Fire Flow inside Project File 1
2. For domestic network, residual pressure is adequate to meet the water demand

3. If activate hydrant system, residual pressure for fire flow drops and unable to cater for hydrant demand

4. Now duplicate the project file (named as Project File 2) and assign Pump (i.e.: Constant Power Pump/ Pump Curve) at pipe location where residual pressure at fire flow starts to fail

5. Run Analysis
6. Now the residual pressure in fire flow calculation will pass with the addition of a pump.

Note:

Since we only incorporate booster pumps for hydrant demand, the peak flow calculation in Project File 2 is irrelevant, hence can be ignored.

Situation 2: Internal Water Reticulation System (Separate Domestic and Hydrant Line) #

The workflow is also the same as the previous situation, where you need to create 2 project files and insert configurable booster pumps/ valves on the second file.

Sample Project File (1): Daily domestic water demand (No Pump – CLOSE)

Sample Project File (2): Hydrant system demand (Add Pump – OPEN)

For this situation, the idea is that engineers can reuse the same main pipes for both normal (peak flow) usage and emergency situations (fire flow). Once the pipes enter the neighborhood, they then separate into domestic and hydrant lines. (Refer image below)

As per the project files above, we use 100mm diameter pipe for domestic line and 150mm diameter pipe for hydrant line, because the water demand surge during fire time is bigger, hence a bigger pipe is required. Normal usage doesn’t require too big of a pipe size.

1. From project file 1, residual pressure is sufficient to supply water throughout the domestic line

2. However, it has not enough pressure to deliver water effectively in hydrant line

3. In File 2, we will install a pump at Pipe 2 to boost pressure and ensure sufficient water supply for the fire line.

4. Once analysis is done, you will see that the residual pressure in fire flow calculation is sufficient to supply water when hydrant system is opened (in a fire emergencies case)

Discussion: #

1. As we can see from the above, during normal time usage the domestic line is adequate, residue pressure is within range. But the hydrant line is not adequate. However we don’t have to care about this hydrant demand because it is not being used.
2. During fire breakout time, we have adequate pressure for the hydrant line. However the domestic line may or may not be adequate, but this is not relevant, because you should run for your life during fire breakout time. Why are you still taking your own sweet time taking a bath? 😂

Why use Configurable Booster Pumps/ Valves? #

We can see the advantages of using configurable booster pumps

1. Cost Efficient Network Design
   • A single pipe network can be used for multiple scenarios. Engineers can reuse the same main pipes for both normal (peak flow) usage and emergency situation (fire flow). So the main pipes from the tapping point ( the reservoir) to the beginning point of the neighborhood will be shared between the normal usage time and fire fighting time.  It’s only when the pipes enter the neighborhood then we start to separate into the domestic line and hydrant line. 
   • This is an economical solution for cost saving purposes, whereby engineers do not have to upsize pipes unnecessarily just to meet the fire flow demand.

2. Pressure Optimization Across All Conditions
   • Booster pump/ valve will only activate when required (e.g.: Activate hydrant system). Or in other words, the pump can switch between different pump curve profiles during normal usage time and firefighting time to cater for different uses.
   • Finally, valve can limit pressure to avoid overpressure/ pipe burst

3. Improved System Stability & Longevity
   • Too low residual pressure will result in non-compliance or service failure to meet the demand. By incorporating booster pump for certain situation where the residual pressure is low, it can ensure sufficient flow and demand during the condition 
   • Massive residual pressure will lead to higher risk of pipe leaking. Therefore, by incorporating configurable valves at certain conditions, it can prevent pipe bursts and leakage during low demand.