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TECHNICAL
Q – Am I allowed to install a PCV upside down ?
By Patrick Gordon of Calafrica ( technical @ calafrica . co . za )
How do I know what is the top or bottom of the valve as there are no markings indicating top or bottom of the unit ?
A - To decide what is the top or bottom of the valve we need to understand what the requirements in SANS 10254 are . SANS 10254 point 5.2 says :
5.2 Discharge from valves The discharge pipes from expansion control and safety valves shall : c ) be so installed that
1 ) they incline downwards continuously to their outlet , 7 ) water traps which could prevent the free return of air into the system do not develop ,
So what does that mean ? If we look at the design of the valve we will notice that the Expansion Relief Valve always protrudes perpendicular to the rest of the valve .
This would be in contravention of the SANS ’ s requirements that call for a continuous downward slope from the valve to the end of the discharge pipe . The water trapped in this area could also prevent the free flow of air back into the system .
In almost all of the installations that I have seen the valve has been incorrectly installed . By turning the valve to face the correct way will not complicate the installation in any way . All that it requires is that we educate the installers that work for us of this requirement .
For further information regarding this , feel free to contact your local IOPSA technical advisor or the manufacturer of your product of choice .
Enjoy your plumbing . PA
The physical workings of the valve do not get affected by the position of the expansion port .
However , if we install the valve with the expansion port to the top we will be allowing some water to be trapped by nature of the installation .
“… that requires for a continuous downward slope from the valve …”
www . plumbingafrica . co . za @ plumbingonline @ plumbingonline @ PlumbingAfricaOnline September 2022 Volume 28 I Number 7