40 TECHNICAL
Plumbing Africa ( PA ) put five questions to the author ( Marcel Ley ) ( ML ) pertaining to plumbing .
( PA ) With regards to space constraints – could I have an explanation as to how constrained this was as a service duct ( for plumbing , HVAC , and fire ), since the space should be designed to accommodate such services ? Was this a design issue ? ( ML ) While the shaft was designed very tight , traditional methods could have been used but with Victaulic requiring less space , the installation was significantly easier that the flanged method it replaced . Expansion and contraction were not part of the original considerations and Victaulic assisted with taking up any movement in the riser .
( PA ) With such constraints , what is the impact on maintenance of the pipes ?
( ML ) Maintenance was made much easier by reducing the number of bolts and nuts per joint from 8 to just 2 , and every joint is a union with Victaulic .
( PA ) Cost is always a factor . Does Victaulic have comparative cost of traditional against mechanical pipes especially in terms of , as stated , time and lifespan ( capital investment and life of product )? ( ML ) Victaulic systems are designed for life of system . In a flanged scenario like originally designed the couplings and the flanges compare very closely in costs . The major cost benefit was speed of installation .
( PA ) Is the pipe SABS approved ? If so , under which SANS codes for each sector ? ( ML ) The specific project was SABS 62 pipe , but Victaulic can be used on all standards of pipe ( SANS , ASTM ). PA
Q : Must all installations have balanced water pressure ?
By
By Patrick Gordon , General Manager of Calafrica ( Pty ) Ltd
Plumbing Africa will extract from various WhatsApp groups the niggling questions that come up again and again . In this issue is the question of balanced water pressure .
P . Gordon
Even though you have two separate stop taps the water is still connected via a ‘ T-piece ’ before reaching the terminal point namely the shower rose .
A : SANS 10254 says that the water pressure shall be balanced at all mixing points . Most installations these days has at least one , if not more , points where the water is mixed before leaving the final outlet .
You may say , “ I don ’ t have any mixers in the installation .” But ask yourself , is there a shower installed ? Even though you have two separate stop taps the water is still connected via a ‘ T-piece ’ before reaching the terminal point namely the shower rose . This is thus a mixer and the water must be the same dynamic pressure at the hot and cold water stop taps .
So only installations where there is no shower and only separate pillar and bib taps throughout the whole installation may be unbalanced .
However , it is still recommended that you always plumb for balanced pressure to all terminal points as you do not know when a DIY person may change the taps at a basin to a mixer .
Q : How can I see if the water pressure is balanced ? A : it is not always easy to just see if the system has balanced pressure . The best way is to use a pressure gauge and to physically check the pressure is at the taps . If you do not have a pressure gauge you could open the taps ( hot and cold ) fully and see if the flow is the same for both . This method could be very messy with water splashing everywhere and is not always accurate as there may be other restrictions in the line that is causing a reduced flow . PA
Ask any question of Patrick for a reply directly , and which will also be published in the next issue of Plumbing Africa . Send technical plumbing related questions to : rory @ interactmedia . co . za or SMS / WhatsApp + 27 ( 0 ) 79 436 1829 .
www . plumbingafrica . co . za @ plumbingonline @ plumbingonline @ PlumbingAfricaOnline November 2020 Volume 26 I Number 09