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Nitrogen

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johnjohn89
johnjohn89 Member Posts: 114
in A-C, Heat Pumps & Refrigeration
Service experts. I have always wondered if the Nitrogen flows through the compressor when brazing it in. If nitrogen does flows through the compressor and how ? Does compressor internal discharge open let nitrogen flow through since only 1.5-2 psi ?

Comments

  • pecmsg
    pecmsg Member Posts: 6,585
    When brazing you only flow at extremely low pressure. (1 1/2#'s it way to high.) All your trying to do is displace any oxygen to prevent copper oxides from forming. ASSUMING something is open on the high side and there's NO control valves yes it just flows through the compressor from low to high sides.
  • pecmsg
    pecmsg Member Posts: 6,585
    Is this a school test question?
    I ask because you posted the same thing on H-talk. 
    johnjohn89
  • ChrisJ
    ChrisJ Member Posts: 16,972
    You need a flow gauge......

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • johnjohn89
    johnjohn89 Member Posts: 114
    pecmsg said:
    Is this a school test question?
    I ask because you posted the same thing on H-talk. 
    Haha
  • johnjohn89
    johnjohn89 Member Posts: 114
    pecmsg said:
    When brazing you only flow at extremely low pressure. (1 1/2#'s it way to high.) All you’re trying to do is displace any oxygen to prevent copper oxides from forming. ASSUMING something is open on the high side and there's NO control valves yes it just flows through the compressor from low to high sides.
    But how?  compressor discharge allow to open since only flow through 2 psi nitrogen?
    and I try to find information about can nitrogen 
    flow through compressor but I can’t find any, do u know where I can find info about that? Thanks
  • pecmsg
    pecmsg Member Posts: 6,585
    Discharge valves are like a check valve, As long as flowing from low side to high side. 
    STEVEusaPA
  • ChrisJ
    ChrisJ Member Posts: 16,972
    edited April 2023
    pecmsg said:
    Discharge valves are like a check valve, As long as flowing from low side to high side. 
    Wouldn't a scroll block the path?
    Although it should be unloaded if not running...

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

  • pecmsg
    pecmsg Member Posts: 6,585
    ChrisJ said:
    pecmsg said:
    Discharge valves are like a check valve, As long as flowing from low side to high side. 
    Wouldn't a scroll block the path?
    Although it should be unloaded if not running...
    Scrolls have a check valve to prevent back spinning. 
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 18,853
    There is no back pressure on the discharge valves since the compressor is not running they will open under little pressure.

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