1. Nominal pressure PN (MPa)
The reference value related to the pressure resistance of piping system components refers to the design given pressure related to the mechanical strength of the 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. Work pressure
3. Design pressure
It refers to the maximum instantaneous pressure that the water supply piping system acts on the inner wall of the pipe. Generally, the sum of working pressure and residual water hammer pressure is used. The design pressure is generally expressed in Pe.
Four, test pressure
The pressure to be achieved for the pressure strength and air tightness test of the pipeline, container or equipment. The test pressure is generally expressed by Ps.
5. The relationship between nominal pressure, working pressure, and design pressureNominal pressure is a kind of nominal pressure artificially stipulated for the convenience of design, manufacture and use. This nominal pressure unit is actually pressure, and pressure is the common name in Chinese, and the unit is "Pa" instead of "N". Nominal pressure in English is nominal pres-surenomina: l in name or form but not in reality. The nominal pressure of the 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 grades, namely 0.250.60, 1.00, 1.60, 2.50, 4.00, 6.40MPa. Design pressure=1.5×working pressure. The working pressure is calculated from the 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)