If a conical strainer cannot withstand high temperatures or differential pressures, it could come apart and cause damage to equipment.

The expected pressure drop across the strainer should not cause the downstream operating pressure to fall below the minimum required pressure of the line e.g. NPSH for a pump.

The perforations of the strainer should be slightly smaller than the smallest piece of debris that is expected to flow through it.

If the perforations are too small, a high pressure drop could develop across the strainer and cause it to fail.