What are the pressure ratings for HP, MP, and LP steam?

HP refers to high-pressure steam, MP refers to medium-pressure steam, and LP refers to low-pressure steam. Steam pressure classification: (1) Low-pressure boilers are those whose steam outlet pressure is less than or equal to 2.45 MPa; the steam temperature in such boilers is usually at the saturation temperature or no higher than 400°C. (2) Boilers with an outlet steam pressure of 2.94–4.90 MPa for medium-pressure applications. For the current parameter ranges of power station boilers in our country, the outlet steam pressure for medium-pressure boilers is specified at 3.83 MPa, with a steam temperature of 450°C. (3) Boilers whose steam outlet pressure at the high-pressure boiler stage is 7.84–10.8 MPa. For the current parameter series of power station boilers in our country, the outlet steam pressure of high-pressure boilers is 9.81 MPa, with the outlet steam temperature typically at 540°C. (4) Ultra-high pressure boilers with a steam outlet pressure of 11.8–14.7 MPa. For the current parameter ranges of power plant boilers in our country, the outlet steam pressure for ultra-high pressure boilers is specified at 13.7 MPa, with the steam outlet temperature being 540°C; in some cases it is 555°C. (5) Sub-critical pressure boilers are those whose outlet steam pressure ranges from 15.7 to 19.6 MPa. For the current parameter ranges of power station boilers in our country, subcritical pressure boilers are specified to have an outlet steam pressure of 16.7 MPa, with an outlet steam temperature of 540°C or 555°C; in a few cases, it is 570°C. (6) Boilers whose outlet steam pressure exceeds the critical pressure, i.e., supercritical pressure boilers. The critical pressure of water vapor is 22.1 MPa. Currently, supercritical pressure levels used in power plant boilers are mostly between 25 and 27 MPa.

What is the trend in price changes for steam at different grades? Thank you

(1) Boilers with a low-pressure boiler outlet steam (LP) pressure of 2.45 MPa or less generally have a steam temperature that is at the saturation temperature or no higher than 400°C. (2) Boilers whose outlet steam (MP) pressure for medium-pressure boilers is 2.94–4.90 MPa. For the current parameter ranges of power station boilers in our country, the outlet steam pressure for medium-pressure boilers is specified at 3.83 MPa, with a steam temperature of 450°C. (3) Boilers whose outlet steam (HP) pressure is 7.84–10.8 MPa. For the current parameter series of power station boilers in our country, the outlet steam pressure of high-pressure boilers is 9.81 MPa, with the outlet steam temperature typically at 540°C.