Issues to consider for piping
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Dear sea friends: While I was on site to assist with the construction work, the construction team often reported that certain pipes had not been drained or emptied, which made it impossible to carry out hydrostatic testing. However, no relevant standards or specifications were found requiring that hydraulic testing of the pipes be taken into account during piping. I’m not sure if anyone is aware of any relevant standards or specifications; if they’re not necessary, what are some good ways to conduct the tests?
There are many ways to connect temporary pipes, and with so many new construction or renovation projects at our factory, we’ve never heard any complaints about this. The formulation of standards is also based on practical construction experience on site; it is unacceptable for the contractors or designers not to be familiar with this.
After all, water flushing and purging are merely procedures carried out before operation begins. The wastewater generated after water flushing can be classified into: drainage from pipeline drainage systems and site-specific drainage systems, residual moisture from purging, purging using hot nitrogen/hot air in cases where there are specific requirements, and dehydration of raw materials, among other methods
The most basic principles for piping are venting at the higher points and draining at the lower points. It only shows that you didn’t carry out the work in a proper manner.
Issues related to high-point venting and discharge points in pipelines: 1. Generally, design firms will incorporate high-point and low-point vents for those pipelines whose operation is significantly affected by startup and shutdown processes, but not all pipelines will have such vents designed. 2. The construction party can add low-point and high-point discharge points during pressure testing, and then submit these to the design firm; the design firm will include these additional discharge points in the final drawings
I’ve encountered this too; there was no high-point vent installed on the pipes in the support frame. Due to the presence of two overhead cable trays, the contractor said that a hydraulic test could not be carried out and suggested using a pneumatic test instead. There’s no choice but to accept it. Later, it became clear that high-point exhaust and low-point drainage needed to be installed.