2 Installation
Minimum diameter | Maximum | Resistance due |
of the discharge | permissible | to each elbow |
pipe from the | total resistance, | or bend (straight |
tundish | expressed as | length equivalent) |
| straight pipe |
|
| length (without |
|
| elbows or bends) |
|
22mm | Up to 9m | 0.8m |
28mm | Up to 18m | 1.0m |
35mm | Up to 27m | 1.4m |
|
| Table 2.2 Resistance |
Examples:
22mm discharge pipe with 4 elbows and of 7m length from the tundish to the discharge point:
Resistance for 4 elbows per 0.8m | = | 3.2m |
Resistance for discharge pipe | = | 7.0m |
Total resistance | = | 10.2m |
The total resistance of the discharge pipe is higher than the maximum permissible value for 22mm pipes (9m). Base your calculations therefore on the next largest pipe diameter.
SAFETY DEVICE | 14188 | ||
(E.G. TEMPERATURE | |||
RELIEF VALVE |
| ||
VENTIL) | METAL DISCHARGE PIPE FROM | ||
| |||
| TEMPERATURE RELIEF VALVE | ||
| TO TUNDISH |
| |
500 MM | DISCHARGE | ||
MINIMUM TUNDISH | BELOW | ||
FIXED | |||
|
| ||
300 MM | GRATING | ||
| |||
MINIMUM |
| ||
|
| FIXED | |
|
| GRATING | |
METAL DISCHARGE PIPE |
| ||
FROM TUNDISH WITH |
| ||
CONTINUOUS FALL |
| ||
| TRAPPED GULLY Diagram 2.5 | ||
28mm discharge pipe with 4 elbows and of 7m length from the tundish to the discharge point:
Resistance for 4 elbows per 1.0m | = | 4.0m |
Resistance for discharge pipe | = | 7.0m |
Total resistance | = | 11.0m |
The total resistance of the discharge pipe is lower than the maximum permissible value for 28mm pipes (18m),which means this pipe diameter can be used.
Water which is almost boiling may escape from the discharge pipe in the event of an error.
IMPORTANT: Risk of being scalded by escaping hot water! Make sure the discharge pipe ends at a safe point inside or outside the building (safe and visible), where there is no risk of anyone coming in contact with hot water.
A suitable point is, for example, under a fixed grating above the trap of a trapped gully. Low discharge pipes, for example up to 100mm above external surfaces, such as parking
TUNDISH
300 MM 
MINIMUM
14189
DISCHARGE
PIPE
METAL
HOPPER
HEAD
spaces, grasslands etc., can be used, provided they are secured by a wire fence or something similar to prevent children from coming in contact with the waste water, and the system is visible. No valves or taps may be installed in the discharge pipe.
Make sure the discharge pipe is at a constant slope of at least 1:200 from the tundish to the discharge point.
The discharge pipe from the pressure relief valve of the boiler (if applicable) can be connected to the horizontal discharge pipe of the solar cylinder behind the tundish with a
2.9 High level discharge termination
Providing that the point of termination is such that persons in or around the building will not be endangered should discharge take place, this method of termination is satisfactory. Points to consider when deciding whether a location for the high level of discharge is suitable are:
Diagram 2.6
The possibility, taking into account wind effect, that someone may be in the path of the water being discharged and if so, whether the temperature of the discharge water will have been sufficiently reduced to not be dangerous. Thermal conductivity of the structure's surface, climatic conditions and location and orientation of the discharge pipe may or may not have an effect on reducing the temperature of the discharge water.
The location of windows and similar openings.
The likelihood of a pram being left beneath the point of discharge.
The ability of structures surface to withstand near boiling water.
The possibility of ice formation if water is discharged onto pedestrian walkways.
15
