Shutdown and replacement of reciprocating compressors
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It is after the reciprocating compressor stops operating and the inlet and outlet valves are closed. During nitrogen displacement, what is the state of the compressor’s intake valve and exhaust valve? Are they both open? Otherwise, why could the replaced nitrogen come out in front of the outlet valve?
It is recommended that you draw a simple diagram so it will be clear at a glance. The intake valve and exhaust valve are understood as check valves. For reference.
I mean, after we shut down the machine, the inlet and outlet of the compressor are already closed. What is the state of the intake valve and the exhaust valve during nitrogen purging? If it is in the off state, why can gas enter through the intake valve and exit through the exhaust valve during displacement?
Nitrogen displacement has a dedicated interface; it would be best to include a schematic diagram. Visuals are more intuitive than written descriptions.
This post was last edited by Passerby_jffdn on 2022-9-2 at 11:03. What you should be referring to are the air valves on the compressor itself; the unloader should be at no load, that is, with the air valves open, in order to allow for gas exchange. Otherwise, gas cannot flow and exchange cannot take place
First, roughly replace the pipeline; once it’s satisfactory, install a blind flange. Next, the gland of the cylinder’s air valve needs to be removed and replaced, otherwise the gas won’t flow properly
Separate nitrogen replacement inlets and outlets are usually provided; closing the main inlet and outlet valves prevents nitrogen from escaping outside the skid
The nitrogen pressure can easily push the valve open, right?
The displacement is in the cranking mode; nitrogen flows along the process path, normally pushing open the gas valve