relief valve safe issue

  • Thursday, October 20, 2016 4:16 AM
    Message # 4314703
    Deleted user

    In most Chinese hospitals, relief valves for compressed medical air and Oxygen are installed before medical gas pipelines enter inpatient areas. The pressure of gases will be reduced from 0.7MPa to 0.4MPa through the relief valve and then the gases enter the inpatient area corridor horizontal pipes and the ward terminal units. My question is: Is this design reasonable ? Is it safe? Thanks for answering.

  • Thursday, October 20, 2016 8:09 AM
    Reply # 4314946 on 4314703

    We do our best to regulate all the medical gases at the source equipment and keep a consistent final line pressure across the entire distribution system.  Having regulators and relief valves scattered throughout the piping can lead to lots of different pressures in different areas.


    So glad to hear from you Johnny.  How are things in China? 

  • Thursday, October 20, 2016 11:04 AM
    Reply # 4315233 on 4314703
    Al Moon (Administrator)

    Hello Johnny:


    So I m trying to envision all those relief valves in an average size 160 bed hospital.

    ? Are all the Oxygen relief valves piped to the outside or vented within the building ?

    Last modified: Thursday, October 20, 2016 11:05 AM | Al Moon (Administrator)
  • Friday, October 21, 2016 7:53 AM
    Reply # 4316610 on 4314703

    I think he is describing regulators Al. 

  • Saturday, October 22, 2016 11:56 AM
    Reply # 4327588 on 4314703
    Al Moon (Administrator)

    and downstream of the regulators are to be relief valves right and relief valve for oxygen systems shall be vented to the outside ( in our world ).


  • Monday, November 21, 2016 3:01 AM
    Reply # 4403239 on 4314703
    Deleted user

    Thanks for your answers. It's quite common to install regulators and relief valves for each floor in order to have pipe sized simply by high pressure at source and adjust pressure for each area,  Therefore, it was assumed that pressure drop is not considered much.(There are not many designer here know how to size pipe correctly) Generally, there are only three sizes of pipe - one bigger size at source and one unified size at each floor (whatever how may beds for each floor) and one size at each room.

    However, There are many problem with such design

    1. Leakage risk at each point of regulators

    2. huge pressure drop if use poor regulators (tiny hole)

    3. Not safety for fire for O2 due to relief valves unless good ventilation nearby each of relief valves should be considered.

    We have to convince hospitals that this is not correct design when it come to safety for fire and patient.

    Do you agree? Any other comments on negative result with such design? Your feed back would be appreciated!

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