How engine oil filter bypass valve or safety valve works - Animation

This animation video explains about the working of an engine oil filter bypass valve, it can be also called as a safety valve. 
As you can see in the above video and understand that the engine oil is stored in the engine oil sump; the oil pump sucks the oil and supplies it to the main oil gallery and different sections of the engine. Before its been supplied the oil gets cooled by the engine oil cooler and gets filtered. After it passes through the cooling galleries. But the path through which the oil passes to the filter, if the filter is blocked or chocked due to impurities it restricts the flow of oil to the galleries from the filter. This will result in oil starvation in the engine there by engine failure can occur due to overheating. 

To avoid this engine oil filter bypass valve is used; it acts as a safety valve. Its working is explained very clearly in the above video. A valve is installed in the path of the oil flow to the filter from the cooler. If the filter is chocked, the pressure at this line increases and exceeds the cracking pressure of the valve and it opens to redirect the flow to the main gallery without filtration, thereby preventing the engine from major failure that can occur due to oil starvation.