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Drainage Features

Is SANS 721 a political standard? (Part 4)

We have a standard that is either both incomplete and incompetent, or we have undue political pressure being brought to bear on committees. SANS 721 cannot offer any comfort to users in its current form and has the potential not to deliver on manufacturer’s claims, that is, those manufacturers that choose to use SANS 721 instead of SANS 8773 — plastic piping systems for non-pressure underground drainage and sewerage.

It is sad that a meeting has not been arranged to resolve this matter while unsuspecting buyers are spending money on a product that, very likely, will not deliver as is required in terms of longevity and reliability.

 

Is SANS 721 a political standard? (Part 3)

One of the biggest concerns in SANS 721 is the UV/weather resistance test and how it is entirely subjective.

Read more: Is SANS 721 a political standard? (Part 3)

Is SANS 721 a political standard? (Part 2)

SANS 721 standard was controversial from the start, because for PP to be used in above-ground applications it must be stabilised to withstand long-term weathering. This process is commonly referred to as ‘carbon black’ and PP must have the appropriate carbon black content or some UV stabiliser.

Technical committees and sub-committees, consisting of industry professionals who freely offer their time for standards to be correctly and intelligently drawn up, have opposed this standard in its current form from the start.

Sections from the executive summary of the assessor’s report are as follows:

“It is concluded SANS 721 has a number of deficiencies” and “The references to SANS 8773 are inadequate and/or inappropriate.” The assessor goes on to state that “SANS 8773 is intended for applications where the products are not exposed to direct sunlight, so the performance requirements are predicated on this.” “SANS 721 does not adequately address long-term weathering. The weathering test taken from SANS 967 does not provide any assurance at all as to the ability of SWV products to withstand the long-term weathering expected when installed in exposed locations. “Requiring PP pipe and fittings intended for outdoor installation to have the appropriate carbon black content would provide a technical solution to the weathering problem. Alternatively, a combination of organic UV stabilisers (HALS) and a suitable concentration of rutile titanium dioxide might provide adequate protection, but this would have to be demonstrated by performing long-term accelerated testing.”

“SANS 721 appears to be an amalgamation of SANS 967 and SANS ISO 8773, with many cross references to the latter. This makes the document difficult to follow

Is SANS 721 a political standard? (Part 1)

Too much time has passed since discussions started on SANS 721:2014, which was published without consideration for the genuine concerns of both the technical committee and sub committees. Subsequently, the South African Bureau of Standards, or SABS, appointed an independent assessor to assess the standard after it had been approved and published. A copy of the assessor’s report is in Plumbing Africa’s possession.

Read more: Is SANS 721 a political standard? (Part 1)

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