Coliter ® Filter Backflow Prevention Device – PN1.0~1.6, 0~80°C, Integrated Filtration & Dual-Check Protection for Water Safety
HSHS41X-A Filter Backflow Prevention Device – Dual Check Valve with Built-in Strainer and Automatic Drain for Hygienic Water Supply Systems
The Coliter® HSHS41X-A Filter Backflow Prevention Device is an advanced dual-function valve that combines backflow prevention and pipeline filtration in a single compact unit, ensuring both the safety and cleanliness of potable water systems. It consists of two independently operating check valves separated by a monitored intermediate chamber, with the first-stage check valve integrated with a removable stainless steel filter screen. Under normal flow, water passes through the filter and both check valves, while the pressure drop across the first check creates a lower pressure in the middle chamber—keeping the automatic drain valve closed. If abnormal conditions occur (e.g., downstream pressure exceeds upstream pressure or back-siphonage), and either check valve fails to seal completely, the differential pressure triggers the safety drain valve to open automatically, discharging contaminated water to atmosphere and creating an air gap isolation that prevents reverse contamination of the upstream supply. This dual safeguard meets stringent hygiene requirements for drinking water networks. Constructed with cast iron, carbon steel, or stainless steel body, aluminum bronze or chrome stainless steel stem, nitrile rubber seals, and stainless steel springs, it ensures durability and reliable sealing. Rated for PN10–PN16 (1.0–1.6 MPa), suitable for media temperatures from 0℃ to 80℃, and designed for water and weakly corrosive fluids. Available in sizes from DN15 to DN400, with threaded (≤DN50) or flanged (≥DN40) connections per GB/T 1241.6 / GB/T 9113, and tested to GB/T 13927 / API 598. Widely used in municipal water supply, building plumbing, fire protection, food processing, pharmaceuticals, and HVAC systems—where clean, safe, and code-compliant water delivery is critical.
Installation diagram
Product Description
| DN(mm) Nominal diameter | Installation method | L | D Pipe thread | D1 | H | H1 | width | n-Φd |
| 15 | Pipe thread | 160 | 1/2" | - | 130 | 60 | 170 | - |
| 20 | 190 | 3/4" | - | 130 | 65 | 180 | - | |
| 25 | 200 | 1" | - | 140 | 80 | 190 | - | |
| 32 | 203 | 11/4" | - | 170 | 90 | 195 | - | |
| 40 | 240 | 11/2" | - | 180 | 150 | 200 | - | |
| 50 | 280 | 2" | - | 185 | 160 | 210 | - | |
| 40 | Flange connection | 420 | 145" | 100 | 250 | 165 | 235 | 4-18 |
| 50 | 500 | 160" | 125 | 280 | 180 | 250 | 4-18 | |
| 65 | 560 | 180" | 145 | 315 | 250 | 425 | 4-18 | |
| 80 | 680 | 195" | 160 | 480 | 285 | 450 | 8-18 | |
| 100 | 760 | 215" | 180 | 500 | 310 | 465 | 8-18 | |
| 125 | 765 | 245" | 210 | 600 | 340 | 495 | 8-18 | |
| 150 | 870 | 280" | 240 | 730 | 390 | 695 | 8-23 | |
| 200 | 1000 | 335" | 295 | 795 | 445 | 730 | 12-23 | |
| 250 | 1120 | 405" | 355 | 820 | 530 | 750 | 12-25 | |
| 300 | 1280 | 460" | 410 | 1000 | 540 | 800 | 12-25 | |
| 350 | 1380 | 520" | 470 | 1150 | 600 | 875 | 16-25 | |
| 400 | 1530 | 580" | 525 | 1200 | 640 | 980 | 16-30 |
The product consists of two separated check valves and a hydraulic transmission to the drain valve. The valve body of the first check valve is equipped with a filter screen. Due to the local head loss of the check valve, the pressure in the middle chamber is always lower than that at the water inlet. This differential pressure drives the drain valve to be closed and the pipeline supplies water normally. In case of abnormal pressure (i.e. the pressure at the outlet is higher than that in the core cavity), even if the two check valves cannot be sealed reversely, the safety drain valve can be opened automatically to empty the backwater and form an air partition to ensure the hygiene and safety of upstream water supply. The secondary product structure has the characteristics of rationality, convenient use, strong sealing performance, durability and beautiful appearance. Widely used in electric power, metallurgy, petroleum, chemical industry, gas, urban construction, papermaking, textile, medicine, food, shipping, water supply and drainage, energy, drilling and other departments.
Main performance specification
| Nominal pressure | 1.0-1.6MPa |
| Nominal diameter | 15-400mm |
| Applicable medium | Water and weak corrosive fluid |
| proper temperature | 0-80°C |
| Flange standard | GB/T1241.6 GB/T 9113 |
| Test Standard | GB/T 13927 API 598 |
Materials of main parts
| Part Name | material |
| Valve body, bonnet | Cast iron, carbon steel, stainless steel |
| Stem | Aluminum bronze, chrome stainless steel |
| Disc | Carbon steel, stainless steel, nitrile rubber |
| Diaphragm | Nitrile rubber |
| Diaphragm pressure plate | Carbon steel, stainless steel |
| spring | stainless steel |
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Faq - Frequent questions
Introduction to Hydraulic control valve
Coliter®’s hydraulic control valves are pilot-operated, multi-function automatic valves designed for intelligent water system management in high-rise buildings, fire protection, and municipal networks. The series includes the 600X electric hydraulic control valve (remote on/off via solenoid), 500X pressure relief/pressure reducing valve, 400X flow control valve, 300X slow-closing check valve, 200X pressure sustaining valve, and the LHS743X low-resistance backflow preventer. All models use system pressure as the driving force—requiring no external power—and feature brass or ductile iron bodies, Y-strainer integration, and precise pilot control for stable operation. Rated at PN16 (1.6 MPa) and suitable for temperatures up to 80°C, they ensure safe, energy-efficient, and code-compliant water distribution with automatic response to demand changes.
