ZDT automatic circulation pump protection valve

The ZDT automatic recirculation pump protection valve is a pump protection device It automatically protects the centrifugal pump (especially for transporting hot water medium) from possible cavitation damage and instability that may occur in the pump body during low load operation Once the pump flow rate is lower than the preset flow rate, the bypass is fully opened to ensure the required small flow rate of the pump Even if the main road is completely closed, that is, the main road flow is zero, small flow can still be automatically circulated through the bypass The pressure is reduced by an integrated multi-stage throttling pressure reducing valve in the bypass.

The ZDT automatic recirculation valve has a larger diameter bypass, which is used for larger bypass flow rates with a pressure difference of up to 4MPa

working principle
According to the different detected main flow rates, the check cone of the main valve disc of the automatic recirculation valve will automatically move to a certain position At the same time, the main valve disc drives the bypass valve stem, transmitting the action of the main valve disc to the bypass. By controlling the position of the bypass valve disc, the throttling area of the bypass is changed, thereby controlling the flow rate of the bypass When the main valve disc returns to the closed state of the valve seat, all flow returns through the bypass When the main valve disc rises to the top position, the bypass is completely closed, and the flow of all pumps flows to the joint system
This valve integrates four functions into one:
1. Traffic perception:Automatic Recirculation ValvesThe main valve disc can automatically sense the main flow rate in the process system, and determine the position of the main valve disc and bypass valve disc based on this flow rate
2. Recirculation control:Automatic Recirculation ValvesThe small flow required for the normal operation of the pump can be sucked into the storage device through the bypass, and the H-Q characteristics of the pump can be adjusted to achieve recirculation
3. Bypass multi-stage pressure reduction: The bypass control system can reduce the high pressure of the reflux medium from the pump outlet to the low pressure suitable for the reflux storage device with low noise and minimal wear
4. Check valve: The automatic recirculation valve also serves as a check valve to prevent liquid from flowing back into the pump body ZDT bypass check is an optional function

feature

Simple structure, reliable and stable operation, with only a few moving parts
Easy to install, can be installed vertically or horizontally at the pressure outlet of the pump
The bypass flow is large, up to 60% of the main flow, and the KV value can be adjusted
Bypass * * working pressure difference up to 4MPa (bypass check function can be selected)
Suitable for other liquid media such as water, oil, methanol, etc., with working temperatures ranging from -196 ℃ to+300 ℃

Material for main parts

*Parts required for bypass with check function

performance parameters

Main external connection dimensions