July and August has seen Commercial and Specialised Diving (CSD) tackle a range of outside work and has afforded us the opportunity to work in some of Britains’ stunning pools and lidos.
Since the early part of the century, Lido pools have become increasingly popular and for the first time in decades more lidos are being renovated than demolished. As we see a close to the summer months and now that the rain has started to fall; outdoor lido and pool owners may be considering draining their pool for maintenance and cleaning purposes but..be aware! Outdoor pools, without any water in them, act as boats with the water table.
As the water table rises due to persistent rain fall, those boats may just decide to try and head for the sea as shown in the picture
To prevent this, outdoor pools and lidos are often fitted with hydrostatic relief valves which open if the water table exerts a pressure greater than the weight of the empty pool, allowing water to enter from the water table below.
These valves come in all shapes and sizes, especially in older lidos. The picture below shows a hydrostatic relief valve that poses an entrapment hazard when open, so CSD were called in to fit a square plastic grille with spacers to prevent any pool users getting their hands or feet caught; whilst still keeping the fitting operational.
In this pool, the sump pot for the valve was filling with debris, causing the valve to jam when it closed. This meant that when the water table dropped, the pool started to leak as the valve was unable to shut properly. CSD fitted a volume reducer around the valve, preventing this issue and allowing the pool to open in time for their summer boom.
