Nitrogen filling for torch process gas pipelines
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I would like to ask the experts: is it necessary to inject nitrogen when the pressure in the torch gas pipeline is low, and is nitrogen injection also required when the pressure is high? What is the reason? Thank you!
This post was last edited by wang*nhua77020 on 2016-3-21 07:02. Adding N2 when the pressure is low is to prevent negative pressure from allowing air to enter； High pressure indicates that gas has entered the flare system; the purpose of adding nitrogen is to displace this gas, as certain materials should not remain in the pipelines for long periods: for example, ST tends to polymerize on its own, and acidic gases can cause corrosion of the pipes.
It was explained on the 2nd floor: nitrogen is added when the pressure is low; if no nitrogen is added, will the fire reach the pipes? And then peng~
It’s easy to understand that nitrogen is added at low pressure to prevent tempering, but what’s the reason for only blowing nitrogen for 5 minutes when the pressure is high?
Additional information: It is at the inlet of the liquid separation tank; nitrogen is supplied continuously at pressures below 1 KPa, and supply continues for 5 minutes at pressures above 1 KPa before it is turned off
Prevent backfire, ensure nitrogen operating conditions and a slight positive pressure in the pipelines； The pressure is required to be below a certain value; it should be increased if it falls below that level and stopped if it exceeds it
I’ve never seen a design like this; usually, for liquefied hydrocarbon spheres, a nitrogen pipeline is required after the safety valve’s vent line to facilitate purging, and the flare itself is designed with built-in functions for pre-purging and post-purging with nitrogen.
Adding nitrogen at low pressure is understandable – it helps to prevent backfire and stops oxygen from being drawn back in. High pressure likely occurs when there is a large amount of gas being released, which raises the pressure in the pipeline system; in such cases, adding nitrogen is probably used to dilute the concentration of air present