Our reference: BF 202/088 5600 5664

Conveyor and Piping Systems cc
248 Mimosa Road
NORTHCLIFF
2198

 For attention: Mr. D Mathy

19 September 1997

Dear Sir

Herewith our results on the above investigation. Please note that this report is subject to the attached.

1. SAMPLE DESCRIPTION

The sample submitted for testing was a yellow unplasticised Poly Vinyl Chloride (u-PVC) pipe. This material is intended for underground use and small scale fire tests were performed in order to evaluated its suitability for this purpose

2. TEST METHODS AND RESULTS

1. Fire Propagation and Heat Contribution (UL 214 - CSIR Modified)

The pipe delivered for testing has a wall thickness of 4mm and an outer diameter of approximately 50mm (2 inches). A 700mm long sample was suspected in a 300mm x 300mm x 2.1m high metal chimney. A Bunsen flame with a length of 60mm and a temperature of 1100 ^oC was applied to the bottom edge of the specimen for a period of 10 minutes. The temperature at the top of the chimney was measured with a K-type thermocouple. The reading form this thermocouple during the test period was compared with that obtained form a blank run in order to calculate that heat contribution of the test specimen.

The material ignited after approximately 20 seconds in the area under direct influence of the heat source. No flame spread beyond that area was observed and after 7 minutes self-extinguished occurred. The heat contribution was found to be negligibly low.

1. Toxicity Test (NES 713)

One gram of material was cut from the submitted sample and burned in a chamber with a volume of 1m³. The concentrations of certain specified gases were determined by means of colorimetric (Dräger) tubes. These concentration were then used to calculate the quantities of gases given off by burning 100g of material in a cubic metre of air.

The toxicity index is calculated from the summation of the ratios of these concentrations to the concentrations causing fatality to man after a 30 minute exposure time.

Gases to be determined and their fatality limits are:

Although the material liberated a high amount of toxic hydrogen chloride gas when forced to burn, it does not promote flame spread and would not burn (or liberate toxic fumes) unless under the influence of an external fire source. The large scale fire behavior could be qualified with a test in our test corridor but normally the use of u-PVC piping underground does not pose a problem form a fire safety point of view. It should however be kept in mind that, besides the fire properties of the piping material, the size of a pipe as well as the installation method would also play a role in the large scale fire behavior of a piping system.

Furthermore, care should always be taken during the transportation and storage of such systems as it is in these states that the material poses the highest fire risk. In general, the use of plastic piping underground should be handled according to the dictates of sound fire management principles to avoid any incidents.

I trust the foregoing will be of assistance to you, but should you require any further information, please do not hesitate to approach the undersigned.

Yours faithfully

K van Dyk

FIRE AND EXPLOSIONS GROUP
On behalf of the Division of Building Technology - CSIR