Vacuum Sewer System Design
Flovac is an Engineering Firm and works with engineering firms all around the world. Local knowledge of the clients and the specific project is essential for a projects success. Flovac’s engineers will work with you with training on how to design your system, checking all calculations or assisting with the full design of the system.
Flovac will come up with the best solution for your project and this may mean that the result will be a combination of gravity sections, some grinder pumps in difficult to get to locations and vacuum sewers.
Flovac offers a Free Service for making concept plans as well as budgets for your project. Contact us to compare how a vacuum system could work in your area.
- Design Flows
- Project Service Area
- Catchment Area Determination by Pump Station
- Pump Station Location
- Locate Collection Pits
- Locate the Vacuum Mains
- Size the Vacuum Mains
- Locate the Division Valves
- Design Long Sections
- Vacuum Pump Station
Every System is Different
Respecting local knowledge is important.There is no “one design fits all” approach that can be taken.What is good practice on the coast in Florida is very different to the experience that designers will face in Malaysia. This is also true for designers in the Nordic countries or in the Middle East. Should different products be used? Is it possible to ship components to a remote island project. Can the pump station be located underground?
Over the years design rules have changed and improved. As so many systems have been installed we can learn about the impacts of correct air injection and the correct ratio of air to liquid and how that can change over time. Many communities have seasonal peak and off peak seasons. Programmable controllers in the field can now be adjusted. You can read about how we can now design and assist changes to flows here.
Gravity Sewer networks have catchment plans, as do vacuum sewer networks. Ignoring those plans can lead to;
- Excess flows.
- Undersized mains
- Pump stations and treatment plants undersized
- High power use
- Flooding and overflows
- System collapses.
Engineers have a good understanding of the limitations of a gravity system, but how many know about the limitations of the vacuum sewer system? Of course we say that vacuum systems are very flexible. That is true as long as we understand the current state of the system and what is being planned still in the future.
In one recent project the system was performing smoothly and with much lower flows than anticipated, this allowed the engineer to replace two existing gravity pump stations with vacuum pits and take the flow into the vacuum system. A system that is well understood from a planning perspective opens up a lot of opportunities.
Master Plan Information
When we are managing Master Plans for clients and looking at sub division changes we look for the following:
- Are the Master Plans properly updated with as-constructed data.
- What flow rates were originally designed for in the system and what are the current flow rates.
- Have densities changed
- What are the calculated head losses on the vacuum lines
- Is the right emergency storage being allowed for
- Did the original design call for a Pump Station Upgrade at some future population density or flow rate.
- Are there other area’s that could now be accommodated
Operational Knowledge is Key
If we have a good Master Plan in place a request for an extension or sub division can happen fairly quickly. The one area that many designers forget is in knowing how well the system is currently operating. Our engineers insist on getting a sign off from our operational group prior to an approval.
If the system isn’t coping with the current flow rate then adding a new hotel or group of houses could cause it to collapse. it doesn’t matter what the designs and Master Plans say, if the vacuum valves haven’t been maintained, if infiltration is occurring, if the vacuum pumps need upgrading then you could make the system worse.
Maintaining Master Plans for clients is part of our Asset Management Support program. If you would like more information about this please contact your local Flovac contact.
All systems undergo change during their life time, a group of 4 houses will become 8 or become a 5 story apartment block. A caravan park could become a group of town houses. A school could become a group of apartments. The faster the designer can approve the development the less pressure they will get from a politician or developer. Flovac can help.
It is important to understand how vacuum systems work. You can read more about that here.
The first step is to see if a vacuum system would be best suited for your project, or a combination of technologies. The second step is to send us a layout of your project, whether it is a septic tank replacement scheme, a new land development, a marina or something else where you may need a vacuum solution. Tell us the flow rates you would like us to use and where the sewage should be sent to.
Next we will work with you on the costings and whole of life costs including operational costs. And then we will work with you on the full design of the system.