TECHNICAL 41
1 . |
Adhesion by tape test – ASTM D 3359 |
2 . |
Hardness by pencil test -ASTM D 3363 |
3 . |
Pull-off-strength test by potable adhesion tester – ASTM D 4541 |
4 . |
Minimum thickness test ( Dry Fil thickness ) - ASTM F 2831 |
Certification for manufacturers must be carried out by accredited third parties such as International Association of Plumbing & Mechanical Officials ( IAPMO )
A tried and tested method should be followed to achieve optimum results , this is clearly spelt out in both the American and BS / European standards . In the absence of local standards and the desire to deliver a complete job these standards are the best we have . Local training does stress this yet why do we continue to have failures that are giving pipelining a poor name ? The primary requirement for a successful lining job is that the pipe ( excluding HDPE ) must cleaned , prepared , and completely dried . Slip up on any one of these and trouble will greet you !
The process is as follows : 1 . Identify the class of leak . One being a pinhole leak and five being , relatively speaking , a ‘ waterfall ’ leak . 2 . This is done by leak detection , condition assessment and pipe tracing .
3 . At the same time , one identifies the condition of the pipe , as there are instances where pipe lining should not actually be done . a . The onus is on the lining professional to trace the pipes in the system and plan the project accordingly . b . Without proper planning the pipes should not actually be lined .
4 . One now prepares the pipe by a method that will ensure a clean line . The selection of the correct grit for sandblasting is important to allow the epoxy to adhere 100 % with different pipe materials requiring different grits . 5 . The terminal fittings should be removed . 6 . Under no circumstances should the application of epoxy by air be in a stop / start manner as this allows for the epoxy to start waving or gathering which will affect the water flow ( the diagram shows several problem areas that arise .
7 . These are avoided by one entry and exit continuous air flow to create the smooth and bonding finish required for water flow .
8 . Where the fittings have been removed , take samples for testing and record keeping . Both standards require record keeping and it serves as protection for the installer as well . An Independent test is highly recommended .
9 . As regards epoxy , it is critical that the temperature and humidity are correct and correctly prepared before application .
10 . All safety precautions must be adhered to as per the OSH Act regarding noxious fumes and handling thereof .
11 . Record keeping and samples of the relining should always be taken to ensure quality control .
12 . Without a sample of the epoxy from the site and a full quality control document in place , it will be impossible to issue a warranty without a QC document from the manufacturer of the system . This practice , should it occur , is unacceptable .
Nu flow
Copper relined .
13 . The manufacturer and the installer need to work very closely as the lining contractor needs the warranty to back him / her up . Not to do this places the pipe liner at risk .
14 . Many times , pipes lined without QC are made worse than before .
We show a properly lined pipe ( cut away )
An installation video is available on the digital copy of this issue .
Done correctly one would have extended the lifespan of the pipe by 50 years or more . PA‐
“ It is a science requiring the knowledge of specialists .”
March 2022 Volume 28 I Number 1 www . plumbingafrica . co . za