Accelerated Life Testing of a Reused Plastic Bottle Bladderless Pressure Tank

Reusing plastic material help mitigate the world wide problem of plastic pollution. In this study a bladderless pressure tank for use with domestic water pumps was designed and built from reused 2 L plastic bottles. Accelerated life testing was conducted to determine the variation of drawdown capacity and recharge time for the plastic bottle pressure tank and comparative tests were conducted with two commercial bladder pressure tanks. The drawdown capacity test for both the 8 L and 18 L bladderless plastic bottle pressure tank showed a linear decrease in drawdown capacity over the accelerated 4 month test period and indicated just over 10% reduction in drawdown capacity after the accelerated 4 month test period. The rate of drawdown capacity decrease per accelerated time test day for the 8 L and 18 L plastic bottle pressure tanks at the 10 L/m and 24 L/m flow rates was 0.7% and 0.55% and 1.43% and 1.30%, respectively. Recharging both the 8 L and 18 L bladderless pressure tanks after the accelerated 4 month test time showed that the drawdown capacity was restored to the original amount. The comparative drawdown capacity test between the commercial pressure tanks and the bladderless reused plastic bottle pressure tank of similar capacity showed similar initial drawdown capacity volume at both the 10 L/m and 24 L/m flow rates. This indicated that the reused plastic bottle pressure tank was capable of performing comparable to the commercial pressure tanks. To maintain the drawdown capacity of the bladderless pressure tank within 10% of the original value, the system should be recharged approximately every 4 months.