D605 Irrigation Low Resistance Plumbing Backflow Preventer With Drain Valve Decompression Type

D605 low resistance decompression type backflow preventer (with drain valve)

product description:

The backflow preventer is a hydraulic control combination device that strictly limits the flow of water in the pipeline only in one direction. Its function is to prevent the backflow of the medium in the pipeline under any working condition, so as to avoid backflow pollution.
The working principle of the backflow preventer is to reduce the pressure due to the mechanical resistance and the overcurrent head loss when the medium flows through the water inlet check valve, so that the inlet pressure is higher than the pressure of the drain valve chamber, and the pressure at the upper portion of the diaphragm of the drain valve is The inlet pressure, the upper pressure of the diaphragm is greater than the discharge valve chamber and the spring resistance, the drain valve remains closed, and the medium flows normally. When the pressure difference between the inlet pressure and the drain valve chamber is less than 0.02 MPa, the medium is in a critical state of backflow. When the upper pressure of the diaphragm of the drain valve is lower than the pressure of the drain valve chamber and the spring, the drain valve is automatically opened, and the backflow medium is discharged outside the tube, and a large amount of air enters the valve chamber to form an air partition to prevent the medium from flowing backward, which is greater than 0.02 MPa. The drain valve closes automatically.
When the water pressure of the pipe network after the valve rises above the water pressure of the forward water of the valve, if the second one-way check valve is sealed, the water body will not flow backward, and the drain valve is closed without draining water, when the second one-way check When the valve seal fails to cause leakage, the drain valve opens the drain pressure relief.

Installation location:

1. The water pipe connected to the user by the municipal pipe network is on the pipe between the back of the water meter and the valve.
2. Introduce the pipe or fire outlet pipe on the fire pump adapter.
3. There is a water supply pipe for chemical injection in the water supply system.
4. The cold water inlet pipe of the heater is on the water supply pipe that may cause backflow.

Installation Notes:

1. Clean all pipes before installation.
2. The backflow preventer is installed horizontally according to the direction of the arrow of the valve body. The installation position should be convenient for height and maintenance.
3. The maintenance gate valve should be installed at both ends of the backflow preventer. The filter should be installed before the inlet, and there should be a flexible joint at one end.
4. The drain of the drain valve should not be less than 300mm from the ground. There should be a drain drain below the drain valve.
5. After the installation is completed, the first time the start is used, the outlet gate valve should be closed, the inlet gate valve should be opened slowly, the medium should be slowly filled with the backflow preventer, and the test ball valve should be opened to remove the valve air. After the valve chamber is filled with water, slowly open the gate valve, let The water fills the pipeline.
6. When the pressure of the imported medium changes, it is normal for the leak valve to leak a small amount of water.

Feature

1. Reduced Pressure Principle Backflow Preventer, Its Standard’s Release Pressure ls 14kpa. Completely Accord Accord With AWWA C511-1997&GB/T25178-2010.

2. Dual Independent &Quick-Closed by Spring Check Valves+Reduced Pressure Chamber + Release Valve+Detectors.

3. Prevent Backflow From Siphon & Back Pressure.

4. Use In Continuous Water Flow,

5. Prevent Backflow From Poison.

6. Online Maintenance

7. Spring Pre-tightening Force Of The First Check Valve Can Keep Un-Leaking From 2m H₂O Column.

8. Spring Pre-tightening Force Of The Second Check Valve Can Keep Un-leaking Fron 0.7m H₂O Column.

9. The Dynamical Head Loss ls Approx 5m.

Optional Material

1.BODY: QT450/Stainless Steel 304

2.COVER:QT450/Stainless Steel 304

3.CHECK VALVES: Stainless Steel 304/QT450(Please Refer to Table 1 for Optional Material)

4.RELIEF VALVE:Stainless Steel 304/QT450

5.SPRINGS:Stainless Steel 304

Supplied Specification

Size:DN40—DN300
DN40—DN50 Threaded

DN50—DN300 Flanged

Pressure:PN10-PN16

Medium:Clean Water

Temp:Temp＜80℃