INTRODUCTION
ZDL 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.
ZDL series Automatic Recycle Valve is suitable for bypass with medium or low pressure differential, maximum pressure differential is 6MPa, and specific choice is determined by factory.
Unique L bypass can eliminated noise by made high-speed flow medium, and prevent cavitation.
CHARACTERISTICS
Multi-cage type bypass, low noise, suitable for medium and low pressure working conditions.
Forged valve body, can choose carbon steel or stainless steel material, etc.
Standard bypass non-return function, maximum working pressure differential is 6MPa.
With venturi port main flow non-return structure, adapt to complicated conditions.
Pressure grade from PN16 to PN100, diameter from DN2to DN500.
Can select manual bypass operation function, used in fault.
SIZE AND PRESSURE RANGE
Body type: Three-way forged body.
Nominal diameter: DN25, 32, 40, 50, 65, 80,100, 200, 250, 300, 350, 400, 450, 500.
Nominal pressure: PN 16, 25, 40, 64, 100 CLASS 150, 300, 600 LB.
End connection: Flange, FF, RF, RTJ, BW,SW etc.
MATERIAL APPLICABLE TEMPERATURE
Body Material
Sealing Material A105 LF2 F304 F316
NBR -20～+100 -30～+100 -30～+100 -30～+100
FKM -20～+200 -40～+200 -40～+200 -40～+200
PTFE -20～+230 -40～+230 -80～+230 -80～+230
SS winding gasket -20～+300 -40～+300 -196～+300 -196～+300
MODEL
ZD L Nominal Pressure Body Material Nominal Diameter /Bypass Diameter Structure Type
Automatic
Recycle
Pump
Protection
Valve L type
bypass
assembly PN16=PN16
CLSS150
LB=CL150 C=WCB
LC=LCB
P=CF8
PL=CF3
R=CF8M
RL=CF3M
D=Customed material DN25=25
NPS1”=1” DN25=25 NPS1”=1” V = Vertically mounted
H = Horizontally mounted
S = manual startup
Such as: L type automatic recirculation valve, pressure is PN40, body material is WCB,Main diameterDN50, bypass diameter DN25, vertically mounted,Model: ZDL-PN40-C-50/25-V
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 funct
