Hydraulic testing of the pipeline
Thread Content
When conducting strength pressure tests on pipelines, is it acceptable to connect several pipes with different test pressures together and carry out the test at the highest test pressure? Is there any problem with doing this? Has there been any clarification in the regulations! For example, in the case of the pump’s inlet and outlet pipelines, the design pressure for the pump’s inlet pipeline is low, and so is the test pressure; whereas the design pressure for the outlet pipeline is higher, with a corresponding higher test pressure. Is it possible to connect the pump’s inlet and outlet pipelines together for testing, using the test pressure specified for the outlet pipeline? Is there any problem with doing this?
Due to different design pressures, the pressure ratings of pipes, as well as those of fittings, valves, flanges, etc., may vary; therefore, it is inappropriate to conduct hydraulic tests using the same test pressure.
It is advisable to install blind flanges at both the inlet and outlet of the pump; otherwise, not only might there be problems with the pipes, but while pipe issues are usually not serious, they can have a significant impact on the pump’s sealing surfaces. Therefore, this practice is not recommended – blind flanges should be used instead.
Not allowed……………………
All done separately~~~ same level
Blind plates are used; they consist of cross-connections installed on the inlet and outlet pipelines of the pump, thereby connecting the inlet and outlet together. The construction crew does this to save time – one test point can be used to check multiple pipelines!
There is no major issue with doing this; although the pressures in the inlet and outlet pipelines differ significantly, the same welding methods are generally used in construction, and the actual quality remains unchanged.
Pumps of different pressure ratings cannot be tested together; even more so, pressure testing of pumps must be carried out in stages!
Segmental pressure testing will not increase the time much
Yes, it’s weld-on-site, and the pressure rating of the pipes and valves is the same, so there should be no major issues