What Are The Different Valves, Their Purpose and Operation.

What is an anti-drain back valve?

A relief valve is located within a filter.

How it operates

• An ADV (made of Silicon or NBR) provides a seal between the element and the inlet holes on the baseplate.
• When engine is stopped: ADV is closed. Oil cannot drain from filter.
• When engine running: Oil pressure opens ADV and oil passes through the filter.

Purpose

• Keeps the filter full of oil when the engine is switched off.
• Ensures a quick flow of oil to engine on start up.
• Prevents oil draining out from the filter’s inlet holes.
• Stops oil from draining out of filter and oil galleries when the engine is shut down.

Notes

• Ryco ADV’s feature a ‘cupped central section which acts like a hinge and requires the outer circumference to stretch to reach the open position.
• An o ring incorporated in this edge regulates the valves to return to closed position.
• Not all filters require anti drain back valve due to the construction of the engine.

What is a relief valve?

A relief valve is located within a filter.

How it operates

Allows oil to bypass the filter if it is blocked or if the oil is particularly thick, which happens when an engine is cold.

Purpose

• If the filter clogs, it opens up to allow unfiltered oil to bypass the filter and ensure continued engine lubrication.
• Normally remains in the closed position because the oil flows through the filter media and the oil is effectively filtered and cleaned.
• Some relief valves are built into the engine block, therefore some filters don’t contain a relief valve. Alternately some filters may contain an up-front relief valve.

Note

• Competitors may use small relief valves which may not allow the correct flow of oil to the engine when the valve is activated.