ensure its suitability for the duty. The low speed Merlin pump has a gentle conveying action to ensure the integrity of the shear sensitive PVC coating. Vigorous action of the gear pumps created too much heat causing the PVC to solidify, and the air diaphragm pumps proved to be very energy intensive.
The Merlin pump showed excellent handling capabilities enabling the liquid PVC to be delivered to the coating
heads at a constant flow rate, crucial to obtaining an even coating.
One of the key factors to consider when using a progressing cavity pump to transfer PVC is the stator material.
Commonly manufactured from rubber the stator is easily dissolvable by PVC. In order to achieve the best results possible, Mono obtained a sample of the medium and ran a number of tests in order to identify the most effective material for the application. The Merlin pump has been supplied with a cast iron stator and shaft seals manufactured from Gore fibre packing, which have proved to be highly effective.
The pump has been running smoothly for two years without any need for spare parts or maintenance. Due to the
success of the installation Bonar Floors are planning to install several more Merlin pumps around the plant.