P-Type Backwash FilterP-Type Backwash Filter
The successor to vertical and horizontal dirt separators, with online blowdown without shutdown and automatic reverse flushing. Full range of sizes from DN50 to DN500.
The P-type backwash filter is the upgraded successor to traditional vertical and horizontal dirt separators, purpose-designed for online blowdown in industrial water systems. Its core innovation is "automatic reverse flushing" — the filter uses the system's own water pressure to backwash the screen and discharge trapped impurities through the drain outlet without shutting down. It features differential-pressure backwash prompting: when the pressure difference across the screen reaches the set value, backwashing is automatically indicated. The product line covers the full range of sizes from DN50 to DN500, with treatment capacities from 19 m³/h to 1980 m³/h. The electrical control system supports manual, differential-pressure automatic, and time-programmed control modes, and the filter can be installed horizontally or vertically.
Key Highlights
Online Blowdown Without Shutdown
Backwashing uses the system's own water pressure, requiring no pump shutdown and no filter disassembly; the system runs normally during blowdown.
Automatic Reverse Flushing
Water flows in reverse through the screen, powerfully clearing impurities from the screen surface and gaps, with a flushing effect far better than manual cleaning.
Differential-Pressure Backwash Prompting
A differential-pressure transmitter or switch is standard, automatically alarming or starting backwash when the screen clogs, enabling unattended operation.
Full Range from DN50 to DN500
From small DN50 pipes to large DN500 main pipes, 12 standard sizes cover the full range, with treatment capacities from 19 to 1980 m³/h.
Multiple Electrical Control Modes
Supports manual push-button control, differential-pressure automatic control, PLC time-programmed control, and remote DCS interlocked control, among others.
Flexible Installation
Can be installed horizontally or vertically; the drain outlet can be rotated 360° to adjust direction, adapting to various piping routes and space conditions.
Working Principle and Structural Features
The following content is excerpted from the P-Type Backwash Filter product manual
Working Principle
The P-type backwash filter is an improved product based on various vertical and horizontal dirt separators and filters. It is equipped with a flow guide device and a drain outlet, allowing automatic reverse flushing of dirt and automatic cleaning of the filter element without shutting down the system.
During filtering, the flow guide valve is open, water enters through the inlet, passes through the screen, and exits at the outlet, with dirt and impurities trapped by the screen. During blowdown, the flow guide valve is closed and the drain valve opened, producing a reverse automatic flush of the screen and discharging the dirt.
The entire backwash and blowdown process does not require shutting down the system and needs no manual cleaning of the filter element, achieving online blowdown. It is suitable for various water supply systems, industrial cooling water systems, and process water systems, especially those requiring continuous, long-term operation without shutdown.
Carbon Steel Body Construction
It mainly consists of a high-grade carbon steel body, filter assembly, flow guide valve, and blowdown device. Specifications cover LX-PG/ZA-50 to 500, with inlet and outlet from DN50 to DN500.
Wide Flow Range
Selection is matched to the pipe diameter, and a single unit handles a circulating water flow of 19–1980 m³/h; provided the working pressure and flow are met, a larger model should be selected where possible.
Automatic Differential-Pressure Backwash
Pressure gauges are recommended upstream and downstream of the filter. Perform backwash blowdown when the inlet-outlet differential pressure exceeds 0.08–0.2 MPa or is 3–4 times greater than when newly installed; a backwash duration of 30 seconds is recommended.
Online Blowdown Without Shutdown
During blowdown, simply opening the drain valve causes the water flow to clean the internal filter assembly automatically. The system keeps running throughout cleaning, so blowdown and cleaning proceed simultaneously without shutdown.
Multiple Control Modes
Powered by an external AC220V supply, it supports remote/local and automatic/manual switching; in automatic mode, backwashing is triggered by a timer switch or by differential pressure.
Flexible Installation
Horizontal installation is recommended, with the arrow aligned to the medium's flow direction. For vertical installation, the water inlet should face upward and the flow should run from bottom to top; a bypass can be added for easy maintenance.
Technical Specifications
| Model | Diameter DN | Treatment Capacity (m³/h) | Filtration Accuracy (μm) | Working Pressure (MPa) | Drain Outlet DN | Dimensions L×H (mm) | Weight (kg) |
|---|---|---|---|---|---|---|---|
| P-F50 | 50 | 19 | 500~3000 | 1.0/1.6 | 25 | 380×520 | 18 |
| P-F65 | 65 | 32 | 500~3000 | 1.0/1.6 | 25 | 420×580 | 22 |
| P-F80 | 80 | 50 | 500~3000 | 1.0/1.6 | 32 | 480×650 | 28 |
| P-F100 | 100 | 80 | 500~3000 | 1.0/1.6 | 32 | 540×730 | 36 |
| P-F125 | 125 | 125 | 500~3000 | 1.0/1.6 | 40 | 620×820 | 48 |
| P-F150 | 150 | 180 | 500~3000 | 1.0/1.6 | 40 | 680×920 | 62 |
| P-F200 | 200 | 320 | 500~3000 | 1.0/1.6 | 50 | 780×1050 | 85 |
| P-F250 | 250 | 500 | 500~3000 | 1.0/1.6 | 50 | 880×1180 | 115 |
| P-F300 | 300 | 720 | 500~3000 | 1.0/1.6 | 65 | 980×1320 | 152 |
| P-F350 | 350 | 980 | 500~3000 | 1.0/1.6 | 65 | 1100×1480 | 205 |
| P-F400 | 400 | 1280 | 500~3000 | 1.0/1.6 | 80 | 1220×1650 | 270 |
| P-F500 | 500 | 1980 | 500~3000 | 1.0/1.6 | 80 | 1380×1850 | 365 |
Product Gallery
Images are from the P-Type Backwash Filter product manual
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