standards / manuals / guidelines for small hydro development

BoulderBusbarButt joint (open joint)Butterfly valveButterfly valveButtress damBypass valveCamberCanalCanal fallCanal head worksCapacitorCapacityCapital costsCapital investmentCasingCatchment AreaA rock fragment, usually rounded by weathering orabrasion, with an average dimension of 12 inches or more:will not pass a 12-inch screen.A heavy metal conductor used to carry a large current.In pipe, flat ends that meet but do not overlap.A valve designed for quick closure that consists of acircular leaf, slightly convex in form, mounted on atransverse shaft carried by two bearings.A disc type water control valve, wholly enclosed in acircular pipe, which may be opened and closed by anexternal lever. Often operated by a hydraulic system.A dam consisting of a watertight upstream part (such as aconcrete sloping slab) supported at intervals on thedownstream side by a series of buttressesBypass (or turbine bypass) valve opens in step with closureof turbine wicket gates to divert flow from the turbine to abypass pipe, thus allowing the turbine to be closed quicklywithout provoking excessive water hammer pressure riseon load rejection. Upon completion of a load adjustmentthe bypass valve closes slowly. This option provides goodprotection against water hammer resulting from loadrejection but can only permit load acceptance at a slowrate. (Alternative to surge tank).The extra height added to the crest of embankment dams toensure that the freeboard will not be diminished byfoundation settlement or embankment consolidation.A channel, usually open, that conveys water by gravity tofarms, municipalities, etc.A structure designed to secure lowering of the watersurface in a canal over a short distance and safe dissipationof the excess hydraulic energy.The beginning of a canalA dielectric device which momentarily absorbs and storeselectric energy.The load for which an electric generating unit, otherelectrical equipment or power line is rated.Costs (usually long-term debt) of financing constructionand equipment.A general term used to identify any money amount whichis to be considered as an investment as opposed to anannual expense. Can be either interest bearing or noninterest bearing.A pipe lining for a drilled hole. The material that isinstalled in wells to prevent the collapse of the walls of thebore hole, to prevent pollutants from entering the well, andto house the pump and pipes.See drainage area.AHEC/MNRE/SHP Standards / General ­ Small Hydropower Definitions and Glossary of Terms 4