In our August blog, we told you about the ‘mighty’ penstock: used to regulate the flow of water when power and precision are required. This month, our series of flow control blogs focuses on Stoplogs. Stoplogs are ideal for use when temporary water arrest is required, and a conventional penstock is excessive in design and cost. In the same way as penstocks, stoplogs have a variety of applications and can be installed for water treatment and wastewater treatment works, power stations, canal lock isolation and other flow control situations. They are most often used during maintenance, to cut off, stop or temporarily divert the flow, or for creating a weir wall. They can be used for longer periods of time where required, for example as a weir structure to help set and control the water’s depth, for ecological or environment requirements i.e. sample points and local wildlife protection.
Traditionally, stoplogs were long boards – usually rectangular – placed together and lowered into slots, prepared in advance, inside weirs, channels, and gates. The only way to adjust the height of barriers is to add or remove stoplogs, through manual lifting poles or semi-automatic lifting beams, and so lighter and stronger barriers have become essential. IBS Engineered Products supply aluminium or stainless (304 or 316) stoplogs in a variety of width and height profiles, according to the size of the channel/aperture and height of water to be retained.
One unique property of IBS stoplogs is the ease of installation, due mainly to the extremely flexible ground seal used. The fact that the IBS system predominantly uses just the frame side and the logs, delivers an extremely cost-effective option, not just with reference to the actual purchase of the product, but also when taking into account preparation and installation. IBS can also offer a stoplog solution which can be deployed directly into existing concrete or steel rebates, with out the need for frames at all – this is an excellent option when replacing older timber style stoplogs or when temporary isolation of the water flow (to allow installation of the frames) is not possible
Frames are available in stainless steel BS EN 10088 grades 1.4301 (304, 1.4401 (316) or 1.4404 (316L), depending on the application and required specification.
Frame mounting options include standard channel rebate, channel sidewall, wall face (on or off-seating), plus special angled or stepped solutions. For extremely wide openings, it is possible to use removable or permanent centre posts to split the logs in to shorter sections.
Pressing tools are provided with each stoplog system to ensure that the ground and intermediate seals are compressed, thereby effecting a greater level of seal than that of other stoplog systems.
The options and advantages of using IBS stoplogs include a number of unique applications. When weight is a consideration, the lightweight aluminium option is ideal for the situation. For drinking water needs, stainless steel 316 stoplogs would be required to meet with drinking water quality regulations. Depending on the size required, a span of over 6m can be achieved, and other bespoke sizes and options can also be created. Due to the proprietary seal mentioned earlier, invert frames are not normally required, resulting in more flexible and cost-effective solutions. (Invert frames are required when using stainless steel stoplogs in a drinking water application, to meet the required standards)
Clearly, as part of the flow control armoury, stoplogs are a versatile and flexible option. The IBS group have been supplying penstocks and stoplogs extensively throughout Europe since 1994, meaning that we have almost 25 years’ experience in their design and manufacture. We work closely with consultants, contractors, and government agencies to ensure that they receive the best possible advice when designing their projects.