IOPSA has worked tirelessly to create awareness and accessibility to the knowledge of the SANS codes however we still see many cases where installations are not compliant due to common mistakes.
Below we explain why an installation is non complaint and how to correct the mistake.
T&P Safety valve overflow pipe has been piped with the correct copper tubing but the incorrect bend has been used.
As per SANS 10254 the overflow pipe needs to be piped using 45 degree bends only.
See extract from SANS 10254 along with the now compliant installation.
5.2 Discharge from valves
The discharge pipes from expansion control and safety valves shall
a) be of a size not less than the size of the connection to which they are fitted with due
consideration to the fact that in runs exceeding 4 m, the size shall be increased;
b) have three or fewer bends, shall not exceed 9 m in length for each additional bend, and
the maximum drain pipe length shall be reduced by 600 mm; all bends shall be a maximum of 45° or
formed with a centre-line radius at least five times the diameter of the drain pipe;
c) be so installed that
1) they incline downwards continuously to their outlet,
2) drainage of both valve and piping is ensured,
3) blockage due to freezing or foreign objects is prevented,
4) when flow occurs from them, the flow can be readily observed with the minimum risk of injury
or damage due to steam or hot water,
5) they are never joined together,
6) each is led to a discharge point which is visible outside the building and in a position where
the discharge from the pipe will not cause a nuisance and also cannot become blocked,
7) water traps which could prevent the free return of air into the system do not develop,
d) in the case of safety valves, always be of metal and be inclined downwards away from the valve;
e) be used for conveyance of water resulting from the normal expansion of heated water and shall
discharge to the atmosphere in a position where the discharge is readily discernible but shall not
inconvenience the building's occupants or cause damage to the building.