Although the trapped fitting isn't essential when fitting to a SW system, it was used in this case to eliminate any problems with smells and sewer gases emanating from the drains. Some of the larger commercial systems are capable of handling flows oflitres per second or more.
It seems that each manufacturer has their own thief-proof locking system for their upmarket products, but most of them rely on some way of attaching the grating to the channel and so rendering them safe ish from the metal bandits that are prowling our town and city centres at night in search of anything they can "weigh-in".
Narrow-opening aluminium grating Class C ductile iron grating Class A galvanised steel grating Galvanised steel slot grating Discreet polypropylene slot grating Class B polypropylene standard grating Gratings generally come in lengths to suit the accompanying channel, usually mm or mm, with one or two units to each channel.
Putting a lower rated grating on a channel, eg, a Class B grating on a Class D Channel, gives the finished unit the lower strength rating, ie, in this example, the finished drain would have a B rating, despite the channel being rated as Class D.
Alternatively, they can be laid on a mm mortar bed over a prepared concrete race.
In certain, specialised applications, such as chemical handling areas or food preparation areas, continuous or jointless drains may be custom manufactured to meet the requirements of a specific project. Some linear channels have simple 'knock-out' holes at the base of each section that can be removed by tapping with a hammer as shown opposite or by sawing, to enable easy connection to a sub-surface pipe.
Accessories and Fittings Mitred Angle Connecting linear channel drains in one straight line is relatively straightforward and simple, but what about curves, corners, angles and junctions? Typical residential linear channel Jointing Linear drains are sectional and therefore there is a joint between adjacent units.
These are designed to cope with the heaviest of flows, and to connect to various sizes and types of drainage. The resulting joint should be sealed with a suitable sealant, such as Polysulphide or silicone rubber to maintain water-tightness. One note of warning, however; the types of 'bargain' linear drain obtainable from DIY chains tend to have cheap, thin, crappy gratings supplied with them.
Whatever the application, whatever the budget, there decathlon slot drainage system be a grating to suit, starting with the cheap-n-tinny Class A galvanised gratings that come as standard with the bargain channels sold in the DIY sheds, through heavy duty plastic polypropyleneductile iron, right up to stainless steel, resin polymers and milled aluminium.
The run-off capacity Q is measured in litres per second and is calculated thus The gratings are strength-rated in the same way as the channels see Table 1 above and so a Class C Channel should have at least a Class C grating.
Most are variations on the theme of an enclosed channel, typically with a u-shaped cross-section and some form of grating over the top.
Overlap Jointing Bitumen jointing compound being applied Other systems, usually the heavy duty, bigger drains, rely on polysulphide, silicon or bituminous sealant between adjacent units to form a water-tight joint, and this method of jointing is also used where a section of drain is cut to fit, thereby losing the 'overlap' joint capability.
For domestic paving projects, these 'off-the-shelf' units, readily available from reputable suppliers such as our prefered supplier, drainage-channel. The flow capacity of any given linear drain can be calculated by another equation, which makes allowances for the dimensions of the channel, the roughness of the material and the gradient. Alternatively, the blockwork pattern can be maintained right up to the edge of the channel.
Once attached to the pipe, the channel is laid on a bed of concrete and tapped down to the required level.
Uses and Classes
Concrete linear channel for Heavy Duty car park use Plastic linear channel for residential use Polymer concrete linear channel for wide variety of uses Galvanised steel slot drain Slot drain end on view Classes of Linear Drain There are 6 'load classes' available which comply to the European Standard DIN there is no equivalent BS and these are shown in the table above.
The end use of the drain will determine which type is most suitable to a specific application. Two basic types of Linear Drain Gratings: Detailing within a block pavement Where a linear drain runs through a block paved area, the paving should be brought up right to the edge of the channel, as shown above, rather than allow a 'fillet' of concrete or mortar to be used between the paving and the channel.
A cheap A-class grating was probably not the best choice for this channel drain outside the doors where they load and unload the beer kegs!
Pipe Union End Cap Outfall Box On larger projects, special outfall units and silt boxes are available to suit each manufacturers range. There are two basic types - those with built-in falls and those that maintain a regular depth along their entire length, and so must be laid to a fall.
Paving is laid tight to linear channel creating a neat and tidy finish Paving has stopped short of the linear channel and been made-up with godawful mortar Enormous thanks to drainage-channel.
Both these methods enable the drain to be converted from a linear drain to a standard, circular sewer pipe which is buried underground and connected to the SW system, as described on the laying drainage page. Bottom Outlet On small domestic application, the linear drain is normally connected to the main drainage via a pipe union end cap or a bottom outlet section.
This equation is beyond the scope of these pages, and it is usually not required as the manufacturers supply full technical support for their products, and have tables and graphs that can be used to find the right drain and gradient for any given run-off capacity requirement.
Once all the channels are laid, they are haunched to prevent them moving, then connected to the surface water system via one of the methods shown above, and finally, the gratings are fitted. In Bitmac Surfacing The channels are laid onto the prepared bed and tapped down to level using a small paviors' mall or rubber hammer.
Idealised Linear Drain They gambling coin machines in a range of sizes, from 50mm deep units for roof drainage to mm deep motorway drains, and in a ever widening range of materials, including polymer concrete, wet-press concrete, HDPE, and stainless steel.
Note that the overall class rating of a linear drain is dependent on both channel and grating meeting these test loads, and the 'whole construction' assumes the loading class of the weaker component. Connecting to Sewer System Obviously, the linear drain has to discharge somewhere, and this section looks at a few of the more common methods used to connect the linear drain with the surface water sewer system.