A strainer system having two separate strainers positioned in parallel, where one strainer can be cleaned while still permitting normal flow through the other strainer. The system flow circuit is arranged so that a high pressure backwashing flow can be applied to one strainer while the other strainer is providing its normal straining function. The backwashed strainer is then isolated by valves so that its access flange can be removed and the particulate buildup within the valve plug cleaned out. The strainer is then returned to service following the replacement of the access flange. In this manner, it is possible to alternate between the two strainers so that continuous flow can be maintained to the hydraulic choke located downstream of the strainer system.