What protective measures should be taken during the purging of welded flow meters in high-pressure steam pipelines?
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The flow meter on the high-pressure steam pipeline is of the welded type; how should this welded flow meter be handled during steam purging? According to the purging plan, corresponding protective measures must be taken when purging instrument components of the welded type. What exactly are the protective measures?
Cut off the table header and open the pressure relief pipeline for venting
It’s a orifice plate flow meter; will it be affected if the orifice plate isn’t removed?
Orifice plate flowmeters also come with transmitters; just remove the gauge head and open the pressure tapping lines! Prevent dirt from entering the transmitter or clogging the pressure lead lines!
The orifice plate can be damaged by impurities in the steam, which affects the measurements; simply protecting the transmitter is not sufficient
Generally, such instruments are installed after purging, to ensure that they are not damaged by the purging process
Currently, the flowmeter is of the welded type; after blowing, welding is done, but there’s still slag that needs to be blown away. For orifice plates, the integrated type might not be removable. It’s also difficult to create a bypass without valves at the front and back.
Refer to the reply above; I’m not very familiar with this area, I’ve only studied * it
Welding is carried out using TIG welding, and skilled welders are required. There is some ash residue; if it is blown out after installation, you know what’s inside the pipes
For such high-temperature and high-pressure pipelines, the material commonly used is 12Cr1MoVG, and argon arc welding is employed for welding them. It seems that only flux of this type is used. Of course, when this is actually blown up, as you said, it’s hard to tell what’s inside. Is it standard practice for weld-type flowmeters to blow out before welding?
I was informed that it is necessary to purge before welding