Kelair Victoria was recently approached by a customer seeking to replace an existing 1.5” opposition branded diaphragm pump. The customer’s business is in the manufacturing of biodiesel derived from waste cooking oil. During this process methanol is used to break down and convert the used cooking oil into biodiesel.

A vacuum is used to extract methanol vapour from a batch reaction vessel. To ensure this process occurs as quickly as possible, the vessel is subjected to the lowest possible pressure. Normally, a vacuum pump would be used for this process. However, due to the small size of the plant and the fact that it is designated as a hazardous area, it would be a complex and expensive task to use an electric vacuum pump. Therefore, an air operated diaphragm pump is used.

When the opposition brand diaphragm pump was used, the customer observed that the pump produced a suction pressure of -40KPa (gauge). However, when it was replaced with a Sandpiper model SP-S15B1ABWABS000, the customer observed a suction pressure of -50KPa (gauge). This 25% increase in vacuum performance meant that instead of the process taking 2.5 hours to complete, it now takes just 2 hours. This means an extra 1000 litres of biofuel can be produced every day.

It should be noted that in order to achieve a better vacuum, the Sandpiper pump supplied was fitted with Buna balls and diaphragms with UHMW seats to ensure better sealing in the ball valves.

The installation of the Sandpiper pump resulted in significant performance enhancements for the plant and should provide benefits for years to come.