Hot water cylinder ( HWC ) installations explained using SANS 10254 ( Part 2 )
By Patrick Gordon of Calafrica ( technical @ calafrica . co . za )
TECHNICAL 35
Patrick Gordon takes a look at the drain cock , with emphasis on how it must comply with SANS 10254 .
The next item in the water supply to the hot water cylinder ( HWC ) is the drain cock . All drain cocks used with a HWC must comply to SANS1808-53 , but I am not going to discuss these criteria in this article . These drain cocks come in all different shapes and sizes and are designed by the HWC manufacturers to complement their specific product .
The purpose of the drain cock is to form an integral part of the HWC and to supply a suitable connection point to the reticulation system . Most of the manufacturers supply the drain cock with a compression fitting on the inlet of the valve . This is ideal as SANS 10254 requires a union type fitting on the inlet and outlet of the HWC for maintenance and replacement purposes . With the compression fitting being part of the fitting , you do not need to fit an extra compression fitting . Even though you may be using a non-copper pipe system , most of the municipalities have that as a requirement for a section of copper pipe to be used on each side of the HWC . the HWC , so that the water that is being drained is not such that injuries can occur and that it will cause the hosepipe to dislodge while draining the HWC .
There are also other drain cocks available in the market that have extra connection points for use with solar systems . You should however make sure with the HWC manufacturer that the use of these fittings do not negate your warranty .
Look out for the next article . We will discuss the vacuum breakers . PA
Not only does the drain cock make it easier to connect to the piping system , but it also does what the name suggests . You can drain the water from the HWC without having to disconnect it from the piping system . The design specification for a drain cock ( SANS 1808-53 ) requires that a serrated tailpiece be part of the drain cock so that a hose can be attached when you need to empty the HWC . You would obviously exercise due caution when draining
Images supplied by Patrick Gordon
May 2024 Volume 30 I Number 3 www . plumbingafrica . co . za