Liquefied natural gas power driving vessel gas supply system double-wall pipe construction process

Abstract

The invention discloses a liquefied natural gas power driving vessel gas supply system double-wall pipe construction process. An internal field construction process includes the steps: 1) completing a construction design scheme and drawing according to a liquefied natural gas supply system drawing; 2) purchasing right-angled bends and manufacturing inner pipes, outer pipes and supporting devices according to the construction design drawing; 3) manufacturing double-wall pipe right-angled bend prefabricated parts. An external field construction process includes the steps: 1) manufacturing double-wall pipe straight sections by a pre-nesting process; 2) welding and closing the double-wall pipe right-angled bend prefabricated parts and the inner pipes of the double-wall pipe straight sections, and performing 100% radiographic inspection for welds; 3) performing air pressure test under design pressure; 4) actually measuring inner pipe closure welds and the length of a shooting position, manufacturing outer pipes at the shooting position, mounting the outer pipes, welding joints and performing routine inspection for the welds. Reworking is decreased, vessel construction efficiency is greatly improved, and construction cost is reduced.

Description

technical field [0001] The disclosure relates to a construction technology, in particular to a construction technology of a double-walled pipe for a gas supply system of a liquefied natural gas-powered ship. Background technique [0002] LNG (liquefied natural gas, Liquefied Natural Gas) gas supply pipeline, as an important system of natural gas fueled ships, is a pipeline system that supplies normal temperature natural gas generated by LNG vaporizers to natural gas engines. Due to the flammable and explosive properties of natural gas, once the gas supply pipeline leaks, it will cause heavy losses to the entire LNG-powered ship. Double-wall pipes should be used, that is, the air supply pipeline is installed in the ventilation pipe, and an independent mechanical exhaust fan is installed in the space between the air supply pipeline and the ventilation duct to realize forced ventilation, so as to ensure the safety of the air supply system. [0003] Combined with the current ac...

AI Technical Summary

Problems solved by technology

[0004] The gas supply pipelines of natural gas fueled ships are generally relatively long, and many places need to pass through complex areas such as the engine room, and must meet the requirements of 100% weld radiographic inspection of the inner pipe. complex

In the prior art, because there is no clear guidance on the construction process of double-wall pipes, it is easy to cause a lot of rework, 100% radiographic inspection cannot be carried out, and the inspection requirements are not met.

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