PUMP STATION DESIGNING - THE INITIAL STEP
With each pump station there is unique design challenges. From designing out potentially smelling to minimising blockage potential, pump stations can be challenging to get right. With us you can be sure you're in good hands!
The first step of the design process is the receipt of the project information. The more information and the more accurate it is early on in the project can sometimes make a critical difference between success and failure on a project. Here is a list of the information required:-
The Cover Level (CL). Sometimes called the Coping Level.
Explanation - The level at which the top of the pump station manhole will end up.
Reason - we need to be able to judge the height differences between this point and the other points below and above ground.
The Invert Level (IL) or as more appropriate for this the Inlet Level. The Invert Level is generally the base of a manhole so be warned, not in this case.
Explanation - the level of the lowest incoming pipe into the pump station.
Reason - we need to understand the depth of the lowest incoming pipe to gauge the correct depth of pump station.
The Discharge Level (DL) or Invert Level at Discharge
Explanation - the level of the invert of the rising main pipe at the final destination or outfall.
Reason - we need to be able to calculate the static height the pumps will have to reach in order to select a suitable pump.
Rising Main Length from pump station to final destination or outfall.
Explanation - the planned length of pipe (rising main) from the pump station to the final destination or outfall.
Reason - in order to select the pumps we need to calculate the force needed to shift the volume of water required through the rising main. Each extra metre means a greater force is required.
Rising Main High & Low Points
Explanation - the points in the rising main where there is a peak or a trough.
Reason - each peak and/or trough will affect the hydraulics and may change the pump selection.
Foul Water or Surface Water
Explanation - we need to be able to determine whether the system is being used for raw sewage, effluent water, surface water run-off.
Reason - different wastewater matter can determine what type of system is required. For example, raw sewage may need a more robust system as it is potentially dealing with more solid matter than an effluent of surface water run-off system is likely to be.
Pumped Flow Rate. Check with us as we may calculate this for some foul systems but will generally always require for surface water systems.
Explanation - the flow rate that needs to be achieved out of the pump station
Reason - to select a pump we need to know what flow rate has to be achieved at the discharge point.
Emergency Storage Volume
Explanation - if the system fails the system needs to store the amount of sewage coming into the system for 24 hours.
Reason - it is generally expected that 24 hours is enough time for an engineer to get to the site and have the system up and running again before it starts filling up the drains.
Rising Main size and material - only required if existing
Explanation - the rising main detail if it has already been installed before we start our design work.
Reason - an existing rising main may restrict the volume going down it and this needs to be taken into consideration.
The way that most of our systems are designed is so that either a on-site built or a pre-packaged system can be utilised as in the design both work in the exact same way with some different considerations.