ZDM Series ARC Valve SS304 2 Inch For Centrifugal Pumps

ZDM Series ARC Valve SS304 2 Inch

TECHNICAL SPECIFICATION:

● Size range: DN25 (1") to DN300 (12") 
● Pressure rating: ANSI Class 150 to 2500
● Connection: Flanged to ASME B16.5 Butt-welding ends to ASME B16.25 Socket-welding or Threaded ends to ASME B16.11, Nipple ends
● Body materials: CS, ITCS, CS+Clad, Chrome Molly /Alloy Steel, Stainless Steel, Duplex,Super Duplex, Inconel and other special alloys

● Temp. range-196℃ to + 538℃(-320℉ to + 720℉)
● Design: API 608 / API 6D / ASME B16.34 ISO 17292 / ISO 14313
● Face to face: ASME B16.10 long Pattern / API 6D

Introduction
The ZDM Series Automatic Recirculation Valve was developed for high pressure centrifugal pump protection. Popular applications include
boiler feed water, petroleum fluids, and steel mill hot strip descale water. In the process of modern industrial equipment, centrifugal pumps are basically required to work in a state of variable flow, which requires automatic control equipment (centrifugal pump protection valve) in the process. However, centrifugal pumps may suffer from overheating, severe noise, instability and cavitation when operating below load, which may cause pump damage. This requires an automatic recirculation device that allows the pump to recirculate with minimum flow through the bypass when the pump is operating below load.
Through years of research and development, continuous innovation and practice, EDVC has developed the ZD series automatic recirculation pump protection valve. Used to prevent damage to various centrifugal pumps due to overheating, severe noise, instability and cavitation when operating below load. As long as the pump flow is lower than a certain value, the valve port of the bypass return valve will automatically open to ensure the minimum flow required by the liquid pump.
 

Principle of Operation
The valve is installed on or close to the pump discharge, just as an ordinary check valve would be. Upon pump startup and without process demand, the bypass is completely open, recirculating the necessary minimum flow. Once process demand starts, the spring loaded
disc is lifted and held in position by flow demand. Until main flow demand exceeds recommended minimum flow, the valve will modulate. As the main flow demand increases beyond recommended minimum flow, the bypass will close and all flow will go to the process.

Application

Boiler feed water, cooling water and condensate equipment in nuclear power plants; petroleum, chemical industry and refrigeration equipment; drinking water supply, wastewater treatment systems; fire protection systems and water injection pumps on offshore platforms; hot rolling descaling and cooling systems in steel plants; loading , Ship's boiler water pump, fire protection system; pulp collapse and snow making equipment in paper mills.

One Valve–Many Functions
The HPM Series Automatic Recirculation Valve is the one
valve that provides at least five essential functions.
Following are those functions:

1. Check Valve Disc prevents reverse flow and positions the bypass for open, closed or modulating flow by detecting the process flow demand.
2. Bypass modulates open when main flow demand falls below the recommended minimum pump flow. Multiple stage pressure reduction prevents flashing/cavitation.
3. Flow Straightener eliminates turbulent discharge. Fluid exits valve as a spray rather than a jet. Reduces erosive wear on downstream piping.
4. Integral Pulsation Dampener protects system from waterhammer if sudden changes in flow demand occur.
5. Integral Check Valve in bypass prevents reverse flow when bypass is routed into a common return line.