When selling and designing copper valves daily, the concepts that will definitely be involved are nominal pressure, design pressure, and working pressure.
In fact, the definitions of these three are relatively vague in practical applications, especially the definition of design pressure. There are many different opinions in the industry. Here is an introduction to the more mainstream pressure standards in the copper valve industry.
defined
Nominal pressure:
Water delivery at secondary temperature (20℃)maximum working pressure, expressed in PN. The nominal pressure is a reference value and for ease of use, the priority number of the R10 series is usually taken. The nominal pressure of the national standard copper valve is PN16, which is commonly known as 16 kilograms of pressure.
Work pressure:
For the safe operation of the pipeline system, the maximum pressure specified according to the maximum working temperature of each level of the medium transported by the pipeline is expressed in Pt. On the construction drawings, the working pressure is usually marked, and the construction party selects the valve with the appropriate pressure based on the working pressure.
To put it simply (translated into words that are easy to understand), the long-term pressure on the pipeline should not be greater than the working pressure.
For example, for a valve with a nominal pressure of 16 kilograms, its daily use pressure cannot exceed its working pressure of 10 kilograms. (Nominal pressure =1.6× working pressure).
In ordinary home design scenarios, the working pressure of general tap water pipes is 4-8 kilograms, while in special use scenarios, such as high-rise and super high-rise buildings, the working pressure may be greater than or equal to 10 kilograms. Therefore, in sales and design, it is necessary to fully communicate use scenarios to reduce potential risks in this regard.
Design pressure:
acting on the inner wall of the tubemaximum instantaneous pressure。Generally, the sum of working pressure and residual water hammer pressure is used.
relationship
Nominal pressure ≥ design pressure working pressure, design pressure =1.5× working pressure
unit conversion
PN10=1.0Mpa= 10kg pressure
