How is the hydrostatic test value for the coils inside the container determined?
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The last edit to this post was made by yechao25038 on 2019-5-11 at 14:10. The following views can be found when searching the forum: 1. For hydraulic testing, 2 times the design pressure of the coil should be used; this requirement comes from the relevant regulations in GB151-1999 regarding hydraulic testing of assembled heat exchange tubes； The new standard has been changed, so this one should no longer be suitable ； 2. Treat the coil as a container, and determine the hydrostatic test pressure in accordance with 150.1—4.6.2 based on the pressure inside the coil ； 3. The hydrostatic test shall be determined in accordance with pipeline-related standards, with a coefficient of 1.5. Our company stipulates that the value for the hydraulic test of coiled tubes should be determined based on the external pressure; in accordance with 150.1-4.6.2, formula 7, the design pressure of the container is used as the external pressure, to which 1.25 is multiplied. Which one do you think is more reasonable?
For external pressure, how should the length of the cylinder to which the external pressure is applied be determined?
Treat the coil as a container, and determine the hydrostatic test pressure in accordance with 150.1—4.6.2 based on the pressure inside the coil
The pressure value that is higher between the pressure values calculated for the pressure resistance test based on the respective design pressures inside the container and inside the coil is used as the pressure resistance test pressure for the coil.
This post was last edited by yechao25038 on 2019-5-13 08:22. It’s just that when determining the hydrostatic test, external pressure should be taken into consideration; it has nothing to do with length, right?~
This does seem more reasonable indeed:victory:
When calculating the wall thickness under external pressure, it is necessary to enter the design data of the pressure vessel; at this point, the length is required
The hydrostatic test value is not calculated using software; it is simply obtained by multiplying the value according to a formula by 1.25. The wall thickness is also determined by the supervisor based on experience; it isn’t calculated. Coiled tubes are usually several dozen meters long, and it’s likely that their thickness would be quite large if calculated using software~:funk:
Not necessarily; it’s not that long even when coiled up, and besides, it gets fixed in place. P
External pressure need not be considered; the coil has a very small diameter but a large thickness, giving it an extremely high capacity to withstand external pressure