Self-reliance type differential pressure control, pneumatic valve selection 2)

the use of differential pressure control pneumatic valve of heating system is a variable flow system. But at present most of the heating network is determined according to the basic need of heating pipe network system of actual hard on-demand unlimited heating, the purpose of using differential pressure control pneumatic valve enables heat users within a certain range according to the heat need to adjust flow. Is bound to cause disorder of hydraulic pipe network system, especially the only pressure difference control pneumatic valve and did not install the heating system of thermal table, hydraulic disorder phenomenon is particularly serious. Now by the basic heating need to on-demand heating transition stage, there are two ways to solve the paradox: (1) increasing network traffic; (2) or at the entrance of the thermal limit traffic on the trunk. Limit flow method to set the flow control of pneumatic valve. Flow control pneumatic valve can choose self-help type pneumatic valve flow control, the balance of pipe network can automatically flow. Each thermal entrance are self-reliance type flow control pneumatic valve, high cost of this way, so use fewer. Another way is set on trunk and self-reliance type flow control pneumatic valve. Currently the vast majority of thermal entrance use lock closed flow control pneumatic valve, this request at the beginning of the pipe network of commissioning required by artificial means to do a good job of initial adjustment, time-consuming, laborious, the work is relatively complicated, difficult to adapt to the change of working condition of heat supply network. But this is a kind of economy guarantee measures of heating pipe network hydraulic balance.
for type selection of pressure difference control pneumatic valve
the differential control pneumatic valve and differential pressure of the pneumatic valve pipe network should be matching
the differential control pneumatic valve working characteristic curve are different in design selection and network operation, pneumatic valve outside the pipe network pressure difference is different. Should guarantee the pneumatic pipe, valve installation points of pipe network pressure difference within the scope of the pneumatic valve to allow changes. The actual pressure difference is too big or too small will disable the spring, led to the pneumatic valve cannot work normally.
the selection of pressure difference control pneumatic valve set pressure differential
to ensure that the pneumatic valve in its best working area. Both are too big to pneumatic valve piping system in actual traffic is too large, differential pressure control pneumatic valve set pressure difference should be and pneumatic valve piping system under the design discharge resistance matching. Causing pneumatic valve hydraulic disorder or piping system results in a piping system in the pneumatic valve too little actual traffic impact heating effect.
the selection of pressure difference control of pneumatic valve diameter
should be based on pneumatic valve working characteristic curve will be piping system design flow pneumatic valve in the pneumatic control valve flow rate range of best work area slants big side is better. Select pneumatic valve diameter is too small, different diameter of pressure difference control pneumatic valve control flow range is different. When choosing pneumatic valves. Pneumatic valve in the control flow range of high-end work, easy to produce noise. Select pneumatic valve diameter is too large, the pneumatic valve in the control flow range of low-end jobs, system flow range is too big, easy cause disorder of outside piping system hydraulic pneumatic valve, at the same time also cause economic waste. Generally in a pneumatic valve pneumatic valve diameter pipeline system interface diameter equal to or better a smaller size.
the differential control pneumatic valve flow control pneumatic valve can not be replaced