Nominal pressure, working and design pressure of pipeline
Nominal pressure, working pressure and design pressure of pipeline
1.What is the nominal pressure PN (MPa)?
The reference value related to the pressure resistance of piping system components refers to the design pressure given to the mechanical strength of piping components. The nominal pressure is generally expressed by PN.
(1) Nominal pressure-the compressive strength of the product at the reference temperature, expressed in PN, unit: M Pa.
(2) Reference temperature: Different materials have different reference temperatures. For example, the reference temperature of steel is 250 ° C
(3) Nominal pressure 1.0Mpa, recorded as: PN 1.0 Mpa
2.what is the working pressure of the pipeline?
Refers to the maximum pressure specified by the maximum operating temperature of the pipeline at each level for the safe operation of the pipeline system. Working pressure is generally expressed in Pt.
3. What design pressure?
It refers to the maximum instantaneous pressure on the inner wall of the pipe by the water supply pipeline system. Generally, the sum of working pressure and residual water hammer pressure is used. Design pressure is generally expressed in Pe.
4.Test pressure
Pressures to be achieved by piping, vessels or equipment for compressive strength and airtightness tests. The test pressure is generally expressed in Ps.
5. Relationship between nominal pressure, working pressure, and design pressure
Nominal pressure is a nominal pressure that is artificially specified for the convenience of design, manufacture and use. The unit of this nominal pressure is actually pressure, and the pressure is commonly known in Chinese. The unit is "Pa" instead of "N". Nominal pressure in English is nominal pres-surenomina: l in name or form but not in reality (nominal, nominal). The nominal pressure of a pressure vessel refers to the nominal pressure of the pressure vessel flange. The nominal pressure of the pressure vessel flange is generally divided into 7 levels, namely 0.25, 0.60, 1.00, 1.60, 2.50, 4.00, 6.40MPa. Design pressure = 1.5 × working pressure.
The working pressure is calculated by hydraulic calculation of the pipe network. 1MPa = 10bar (bar) = 10.2kg / cm2 = 100N / cm2
Test pressure ＞ Nominal pressure ＞ Design pressure ＞ Working pressure
Design pressure = 1.5 × working pressure (usually)
