Q345R hydraulic test temperature
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According to GB150, when conducting a hydrostatic test on containers made of Q345R, the liquid temperature must be no lower than 5°C. The company has many units whose cylinder heads are made of Q345R, but whose nozzles are made of 20#. Our process responsibility engineer, considering that the nozzle material is 20#, requires that the pressure testing temperature be no lower than 15°C. Is this reasonable? Can’t the hydraulic test be carried out at a temperature of not less than 5°C?
Which teacher can tell me how you do it? In the past, as long as the cylinder head was made of Q345R, I would consider that a hydrostatic test at temperatures not lower than 5°C was sufficient, without taking the nozzles into account
We haven’t considered taking over either; are there any other well-founded answers? Wait around
There’s really nothing that can be done about being too picky on this; version B also requires a temperature of at least 20 degrees Celsius, so that should be taken into consideration as well. I think it’s sufficient to focus on the main material used.
This post was last edited by bcfshr111 on 2019-7-31 at 15:44. I agree with the view in post 4; in the definition of 150, there is no mention whatsoever of pipes or any standards related to them regarding the hydraulic test pressure. The purpose of a hydraulic test is primarily to assess the overall strength and sealing performance of the equipment; therefore, I believe that the temperature for the hydraulic test is determined by the main materials used, and it has nothing to do with the fittings. As a supplementary note: In clause 11.4.9.3 regarding test temperatures in GB150.4, it is explicitly stated that \"the temperature of the liquid used for the hydraulic testing of low-temperature vessels should be no lower than the impact test temperature of the vessel material and welding joints plus 20°C\", and that \"during testing, the test temperature must be at least 30°C higher than the temperature at which the metal of the vessel wall loses its plasticity.\" I think the material of the housing and the walls of the container here are already quite clear.
Only the main material is considered, not the fittings. If the diameter of the fittings is too large, it’s better to take that into account; generally, the fittings can be ignored
Taking into account the test temperature, it is set between 5 and 50°C.
If the span is 250 or more, it constitutes a primary stressed member, and the temperature for the hydraulic test should be considered； If it is less than 250, it does not belong to the main compression members and can be handled as appropriate.
Originally, 5 degrees is also a value determined artificially; it is related to both the material’s inflection temperature and its thickness. There’s no need to worry about 5 or 15 degrees; moreover, the strength margin of the joint is sufficient, so 5 degrees is no problem at all.
The process responsibility engineer said that the connections on the equipment also have to withstand the hydrostatic test pressure, and this should be taken into consideration. In reality, temperatures are low during winter here, so it’s impossible to maintain a temperature of 15 degrees Celsius. Moreover, with volumes of hundreds of cubic meters, it’s not possible to heat the water either. In other words, the temperature of the file itself must be no lower than 15 degrees Celsius
Everyone believes that the main material is Q345R, so a pressure test at no lower than 5°C should be sufficient.