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32 Cards in this Set
- Front
- Back
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Advection-dispersion-decay |
The movement, longitudinal spreading (via turbulence), and disappearance of a substance being transported in a fluid (usually a dissolved substance) |
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Appurtenance |
A part or piece of a larger system which advances and/or facilitates the purposes and function of the larger system. PW example: gate valve |
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Ballast thrust block |
Used in situations wherein the watermain (and the flow within it) changes direction in a vertical plane, as might happen when a watermain laid with zero slope (passing through flat area) must suddenly extend into an area that is steeply sloping. Dead weight of block resists upward thrust. Aka vertical thrust block; they encompass the elbow (say) and 'hang' from it |
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Bourden gauge |
A type of pressure gauge that is based on the uncoiling of an evacuated spiral of tubing, as the internal pressure increases within the coiled tube |
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Butterfly valve |
A valve which involves the rotation of a circular plate about a vertical in-plane line through its axis, used in large diameter pipes |
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Characteristic curve |
The relationship between the head that a pump can generate (ordinate) and the flow that it can produce (abscissa). Often a slightly bowed line with a negative slope. Unique to pump in question & unique the impellor installed in that pump. Actual head and flow realized will depend on the nature of the system (forcemain, eleven diff, fittings etc) to which pump is connected. |
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Corporation Stop |
A small globe valve which is screwed directly into watermains, where the service lateral connects to the watermain (at the upstream end of a lateral). It must be turned on before being buried. |
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Cross connection |
The physical possibility of a flow reversal in a potable system, often backward through a lateral. Caused either by back-siphoning or by a source of actual pressure in the building being serviced by the lateral. Often represents/causes a serious health hazard to consumers. Preventable through the installation and maintenance of proper appurtenances, such as reduced-pressure-principle back flow prevention valves. |
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Cross-connectio control example |
Installation of vacuum breaker valves on irrigation system. |
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Curb stop and drain |
A valve in a service lateral, located at the property line. It is at the bottom of a service 'box', within which is a rod which can turn the nut on top of the curb-stop-and-drain. The top of the service box (valve box) associated with this little valve should be in an obvious location; it has a recessed 5-sided nut in its centre (so that a special tool is needed in order to operate it). This is the valve in one's service lateral that is shut off by the water until it if you don't pay your water bill |
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Dynamic total head with pump placed between 2 very different energy conditions at system boundaries |
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Easement |
A piece of property that enables the water utility to legally access the part of its system that is within the easement, such as for maintenance purposes. Typically strip of land located adjacent to and between private properties, & services in question are below grade |
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Gate valve |
Circular plate is raised or lowered using a threaded rod. Stops the flow isolates problem. Not used in larger diameter water mains. Sometimes leading edge covered with thick polymer to get more watertight seal |
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Hydraulic transient |
A high speed pressure perturbation caused by such things as rapid valve closure, sudden pump stoppage, or collapse of an air gap. Characterized at a given location by usually high (or usually low) pressures that last for a brief moment in time, but which can damage the pipeline. |
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Mechanical restraint |
A short thick circular collar that is made of metal, fitted with tooth-like pipe grippers at regular intervals around circumference of collar. Uses - placed over push-together (Tyton) joints intended to prevent separation of joints. -1st lengths of pipe next to flanged elbow -resist system pressure & momentum -used when concrete thrust restraint difficult & when soil conditions poor |
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Minor loss |
An energy loss that is not caused by pipe friction. Happen at specific points in system. Quantified as fraction of kinetic head Ex. Reservoir exit, pipe fittings |
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Multi-player intake |
Structure that enables water utility to draw off water at different sub-surfa elevations, with water body (lake). Can draw water where there is less suspended sediment. Not usually used unless large service area, tower-like apperance |
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Operating point wrt pumping |
Intersection between characteristic curve of pump and system curve it is connected to. It's location on the plot defines/implies certain head (dynamic total head, on ordinate) and rate of discharge (on abiscissa) |
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Pitot tube |
A device that uses the stagnation principle to measure velocity, such as velocity of flow that emerging from a fire hydrant. Converts kinetic head to pressure head. |
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Pressure reducing valve |
Used to both sustain & limit pressure in a given downstream zone of hydraulic head, in spite of fluctuations in demand that occur downstream of PRV chamber. PVR make use of upstream-downstream pressure difference to internally self-adjust. Set so pressure that remains on the downstream side ( and hydraulic head downstream ) remains constant. |
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Rapid closure |
A valve closure which occurs more quickly than the round-trip time to a reservoir (or other pressure relaxation point) in potable system. |
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Run-up head |
The head produced by pump if it is connected to nothing (no receiving pipe on the discharge side). It is a low head |
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Shut-in head |
The head produced by a pump if the flow has no where to go (perhaps valve on discharge side is completely shut). It is a high head. |
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Slow closure |
A valve closure which occurs less quickly than the round-trip time to reservoir (or other pressure relaxation point) in the system. |
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Static discharge head |
With pumps placed in between two very different energy conditions at system boundaries |
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Static suction head |
With pump placed in between two very different energy conditions at system boundaries |
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Static suction lift |
With pump placed between two very different energy conditions at system boundaries. |
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System curve |
The relationship between hypothetical head and hypothetical discharge, for a conduit supplied by a pump |
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Thrust block |
A trapezoidal block of concrete that is used to resist the thrust exerted by watermains at locations where there is a change in planimetric direction, such as elbows. Thrust force caused by water pressure and momentum change from direction change of the flow. Also found at T's under fire hydrant boot and at any blank end in system. Poured in place to ensure full contact with soil, needs custom framework. |
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Tuberculation |
Mineral deposits (internal scaling) that builds up on the inside of water mains (especially cast iron water main), decreasing diameter and dramatically increasing frictional effects. |
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Upset bid |
A bid in which are 'hidden' certain high-priced items that are based on contingencies. (if these conditions are realized the cost of the project could skyrocket) |
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Water hammer |
Hydraulic transient. Occurs within potable water distribution systems |
