Can the Flovac Valve and Controller work under water
Vacuum sewerage systems are often installed in areas which are prone to flooding and rising water tables. A question we are often asked is
“Can the Flovac Valve and Controller stilloperate when they are under water”
The simple answer is yes!
The writers of the British and European Standard for Vacuum Sewerage Systems EN16932-3:2018 and the stricter Australian Standard for Vacuum Valves AS 4310 required that a number of independent tests be undertaken. The Blockage test (seen here) and the Submergence test were two of the most important.
The reason is that “A submergence test is conducted to confirm that the valve can be installed in flood-prone areas” In Annexure A.3 in the European Standard and Appendix F in the Australian standard it outlines what is required for the testing.
The USA does not have any standards for vacuum sewer systems so utilities should rely on other International standards.
The stricter Australian standard requires that the valve, controller and all fittings shall be capable of continuous operation without failure when immersed to a depth of 1,500 mm (5 feet) above the top of the valve body in water and/or floodwaters, which may contain large quantities of sediments. The European standard only requires that the valve is covered by 300 mm of water.
Flovac had independent auditors Dekra carry out all of the testing requirements covered in both standards. Dekra are one of the largest and most respected testing and certification organisations in the world, operating in 50 countries and with 45,000 employees.
The DEKRA Test procedure and P for Pass
Whenever our operations group has found a failure of a Flovac valve or controller at a project site which has been subject to flooding, in all cases it has been due to incorrect installation. Either due to hose clamps not installed or o-rings left off. In areas which are badly affected by flooding we will often install the controller in a dedicated pedestal next to the collection pit. This is not to protect the controller, which can still operate when submerged, but to allow the operator to fire the vacuum valve which might be covered by floodwater.
This video shows a Flovac valve with monitoring operating under water.
For those operators with a Flovac Monitoring System the valve can be fired remotely either via your phone or other IOT device.
If your project is subject to flooding there are a number of other protective measures which can be taken (read this article for more information)
With the recent move to a new international production facility in The Netherlands, the first thing that General Manager Mr Leo Huijs had to set up was new ISO certification for the new facility.
ISO 9001 covers Quality and ensures that Flovac is set up to produce and deliver products to our clients in such as way as to ensure we will have every aspect of production and logistics set up to always deliver defect free product.
Not just our own operators but our clients as well. Much thought is given to the design of our vacuum pump stations, our collection pits, our vacuum valves and our monitoring systems to ensure that at the front of our mind is the expectation that everything that we design and produce will provide a safe environment for all operators of vacuum sewerage systems.
ISO 14000 is a family of standards related to environmental management that exists to help organizations minimize how their operations negatively affect the environment; comply with applicable laws, regulations, and other environmentally oriented requirements; and continually improve.
Although vacuum systems are newcomers to the sewerage industry we are seeing some systems just reaching their 50th anniversaries. Materials and designs have changed significantly since the first systems were installed in the mid sixties and although many are still operating they are nearing the end of their design life of the time.
When looking at whole of life costs the primary maintenance item in the vacuum pump station are the vacuum pumps. Liquid ring pumps have lower ongoing costs but use a lot of water which can be expensive. Rotary vane Pumps require oil changes and filter changes and rebuilds are more common.
Gravity sewers have been used for hundreds of years, but they come at a much higher cost than many options reports accurately record. When selecting what type of sewerage system to use, take into account the risks associated with the solution. What happens if a sewer overflows? What happens if a storm or large wet weather event occurs. What will happen if a pipe breaks. What will be the cost and what will be the risk? A vacuum sewer could be far cheaper than you realise.
Sewage leaks can occur for a number of reasons. the most common is leaking sewer pipes (this may be caused by tree roots or ground movement). A break in a gravity line can remain undetected for months or even years. In a Low Pressure Pump system a break will lead to a surcharging sewer which will be difficult to repair and costly.
In the USA the 
Owners of Marina’s know the impact of attracting houseboats and tourists if sewage is contaminating the marina area, with bad smells putting off people going to local restaurants.
Well admittedly, homeowners can still create overflows at the home and badly maintained systems will always have problems. Modern wireless and cable monitoring systems reduce this risk considerably and is a game changer.
If a blockage has occurred and sewage is backing up in the pit it cannot overflow through the manhole cover as there is a partition between the sump and cover preventing sewage from flooding at this point. If it starts to back up towards the house a high level alarm in the pit sends an urgent alarm to an operator who attends to the problem. If the problem is hard to solve or an experienced operator is not available a suction truck can be used at this point.