INTRODUCTION

ZDM Series Automatic Recycle Valve (ARC valve) is a kind of pump protection device. It automatic protect centrifugal pump when pump body occur cavitation damage or unstable (especially conveying hot water at low load operation medium). Once pump flow is lower than the preseted flow, bypass can completely open to ensure the minimum required flow pump. Even running fully closed, namely running flow is zero, the minimum flow can also pass bypass for Automatic Recycle. Pressure reduced through the multistage bypass pressure reducing valve.
ZDM series Automatic Recycle Valve is suitable for bypass with high pressure differential, maximum pressure differential is 30MPa, and specific choice is determined by factory. Multistage decompression type M type bypass can eliminate noise made by high-speed flow medium, prevent damage of cavitation erosion and braising to valve components.

CHARACTERISTIC

• Prevent cavitation multistage decompression bypass, reducing velocity, suitable for high pressure conditions
• Forgde valve body, or you can choose carbon steel or stainless steel material, etc.
• Standard bypass non-return function, maximum working pressure differential is 30MPa.
• Pressure grade from PN16 to PN420, diameter from DN2to DN500.
• Can select manual bypass operation function, used in fault.

SIZE AND PRESSURE RANGE

• Body type: Three-way forged valve
• Nominal diameter: DN25, 32, 40, 50, 65, 80,100, 200, 250, 300, 350, 400, 450, 500
• Nominal pressure: PN 16,25,40,64,100,160,250,420 CLASS 150, 300, 600, 900, 1500, 2500LB
• End connection: Flange, FF, RF, RTJ, BW, SW etc.

MATERIAL TEMPERATURE RANGE

WORKING PRINCIPLE

According to the difference of inductive main flow, main valve disc check cone of automatic recirculation valve will automatically move to a certain position. At the same time the main valve disc drive bypass valve stem, transfer the movement of main valve disc to bypass, through control bypass valve disc position, change bypass throttling area, so as to control bypass flow. When main valve disc back into valve seat closed, all flow backflow through bypass. When mian valve disc to rise to top position, bypass is fully closed, all the flow of pump flow to process system. This valve set four functions in one body.

 

• Flow perception: automatic recirculation valve main valve disc can automatically perceive main flow of process system, thereby according to the flow to determine position of mian valve disc and bypass disc.
• Recirculation control: automatic recirculation valve can inhaled pump normal operation required minimum flow into storage device through bypass, so as to adjust pump H – Q characteristics, to realize recycling.
• Bypass multistage pressure reducing: bypass control system can reduced the backflow medium from high-pressure pump outlet to appropriate backflow to low-pressure storage device with low noise small wear.
• Check: automatic recirculation valve also has check valve effect, preventing the liquid backflow to pump body. Bypass non return function is standard.
• Special bypass size can be customized. The max flow rate of bypass is subject to the max Kv value.

SIZE

Note: Valve mian ouelet size depends on the outlet size of pump.

MODEL SELECTION

NOTE

Other bypass size can be made according to client’s requirements, maximum bypass flow depends on maximum Kv value.

INSTALLATION

automatic recirculation valve should be installed nearby the centrifugal pump need Protect as soon as possible, and be better to install the outlet of pump.
Distance between pump outlet and inlet should not exceed 1.5 meters, in order to preventing from liquid pulsing cause low-frequency water attack. Medium flows from top to bottom. Priority should be installed vertically, also can be installed horizontally.

MAINTENANCE

Maintenance and installation according manual provided, inspect the pump weekly in routine, and at the same time inspect valve functions.

MAIN PARTS AND DIMENSION

DIMENSION AND WEIGHT