M Series pumps are normally warrantied for 365 calendar days from the date of shipment. However, the warranty period may be shortened or voided altogether by factors such as an extreme duty cycle (i.e., excessive speed of continuous flow or excessive number of revolutions), use of chemicals incompatible with the pump's wetted materials, or too high a fluid temperature.
Expected lifetime is considered to be 1,000,000 revolutions using DI water at 5 ml/min (M6) or 25 ml/min (M50) at room temperature, without back pressure. At maximum continuous flow, 1,000,000 revolutions is reached in about 14 days (M6 at 5 ml/min) or about 17 days (M50 at 25 ml/min).
In terms of volume, expected pump lifetime at maximum continuous flow is about 100 L for M6 or 625 L for M50.