Automatic Drain Strainer

Automatic drain strainer is an intelligent self-cleaning pipeline filtration device that combines impurity interception and automatic sewage discharge functions into one unit, eliminating regular manual disassembly and washing required for conventional Y-type, T-type and right-angle strainers. It is specially designed for medium pipelines with high impurity content, continuous long-cycle operation and inconvenient on-site maintenance, widely installed upstream of pumps, heat exchangers, compressors and precision control valves to intercept rust scale, sand, welding slag, suspended solids and granular dirt while discharging accumulated contaminants automatically without system shutdown.

Its complete assembly consists of a high-strength strainer body, multi-layer stainless steel filter cartridge, automatic drain valve, differential pressure sensing module and control accessories. During normal operation, fluid flows through the inlet and passes evenly through the mesh filter element, and clean medium flows toward downstream equipment, while solid pollutants are trapped inside the filter cavity. As debris builds up on the screen surface, the pressure difference between the inlet and outlet gradually rises. Once the differential pressure reaches the preset threshold, the sensing system instantly triggers the built-in drain valve to open. High-speed fluid scours the inner wall of the filter basket, flushing all sediment and impurities out through the drain outlet rapidly. After a fixed flushing duration, the drain port closes automatically, and the strainer resumes normal filtration circulation. Some models also support timing automatic drainage as an alternative control mode, enabling periodic dirt removal independent of pressure changes.

Unlike common manual strainers that need to stop the whole pipeline, detach the end cover and take out the screen for cleaning, this automatic structure realizes online non-stop sewage discharge. The filter element stays mounted inside the body throughout the flushing process, so the pipeline never cuts off medium supply, greatly improving the continuity of industrial production and avoiding economic losses caused by frequent equipment shutdown. The internal filter cartridge adopts reinforced 304 or 316 stainless steel woven mesh with customizable mesh counts to meet different precision requirements for water, oil and low-viscosity chemical media. The strainer body is available in ductile iron, carbon steel and stainless steel materials, matched with EPDM or PTFE sealing gaskets to adapt to cold water, hot water, circulating oil and low-temperature steam working environments. Standard pressure specifications include PN10, PN16 and Class 150, with flange and grooved connection ends covering DN50 to DN300 for both branch pipelines and medium-diameter main lines.

Installation and operation are highly flexible. The equipment can be arranged horizontally or vertically as long as the drain outlet faces downward for smooth dirt discharge. The control panel allows operators to adjust differential pressure trigger values and flushing duration on site according to actual impurity concentration in the medium. The fully enclosed structure effectively prevents medium splashing during drainage, keeping the equipment room clean and reducing potential safety hazards brought by manual cleaning. In terms of service life, the automatic backwash flushing reduces long-term dirt adhesion and blockage on the filter screen, slowing down wear and corrosion of the filter element and extending its service cycle significantly compared with traditional strainers.

This strainer solves prominent pain points of conventional filters: frequent maintenance workload, production interruption during cleaning and blocked pipelines caused by delayed manual washing. It is the optimal filtration solution for unattended pump stations, remote industrial workshops and large circulating water systems with heavy dirt loads.

Core Advantages

Integrated automatic drain and differential pressure sensing design, online self-cleaning without pipeline shutdown

Eliminates frequent manual disassembly, flushing and screen replacement, cutting labor maintenance costs

Dual control modes of differential pressure trigger and fixed timing flushing to fit diverse working conditions

Reinforced stainless steel filter cartridge resists clogging and abrasion, supporting long-term continuous operation

Multiple body material and connection options compatible with water, oil and mild corrosive industrial media

Vertical downward drain layout ensures thorough discharge of heavy sediment and solid particles

Fully sealed flushing structure avoids medium leakage and splashing during sewage discharge

Main Application Scenarios

Industrial circulating water systems, municipal sewage pre-filtration pipelines, fire protection large-flow water supply mains, power plant cooling water loops, petrochemical medium conveying lines, HVAC central circulation systems, unattended water pump stations and agricultural irrigation trunk pipelines.