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  1. Boiler1

    -94 F dew point dry air - issue with condensation

    Greetings, I have got an Oil Free Air system with desiccant dryers set to -70 degC / -94 F dew point. The system pressure is maintained at 7bar / 100 PSI. The system dew point is monitored at several locations downstream form the central plant and its maintained within the spec (-70 degC / -94...
  2. Boiler1

    Utilities capacity planning tool or software?

    Hi All, This may not be the right forum for the topic, however, could anyone suggest a good utility planning tool or software where the end user add-on can be monitored against the distribution network and central plant capacities as set up on that tool . Something that will give an early...
  3. Boiler1

    Liquid ring Vac pump - water in the exhaust

    Hi All, Apologies for delayed response. We have borescopped the separators on all the pumps and it turns out one of the pumps is circulating significantly more water when in operation. I mean - much more! The other pumps are working as expected with seldom droplets being pulled into exhaust. At...
  4. Boiler1

    Liquid ring Vac pump - water in the exhaust

    Hi All, I’ve got a set of liquid ring vacuum pumps operating on 24/7/365 basis with periodic duty/stand by rotations. There is a dedicated separator tank looped with each pump to maintain the water seal during operation. These separator tanks are vented through the common exhaust header with...
  5. Boiler1

    Use of recirculated air as a make up in clean rooms?

    Hi all, I am looking at the cleanroom set up where the make up air handlers (MAH) are used for pressurisation, i.e. to compensate for any leaks and some specialist exhaust from the area. A separate full recirculation HEPA filtered AHU's are used for air change rates and the cleanroom class...
  6. Boiler1

    Stainless to copper transition for fire stopping

    Wow! Thank You all for great comments! I would have replied individually if there was an option. As to the purpose of the copper spool and the mechanism how it works, I believe the idea for the spool is to melt down and stop the fire that way. I have only seen the flame arresters doing the same...
  7. Boiler1

    Stainless to copper transition for fire stopping

    Hi All, I’ve noticed a copper spool fitted to otherwise stainless-steel pipework. The length of the spool was approx. 10 pipe diameters and the installer’s explanation was that the spool is installed to stop the fire spreading inside the pipe. Is this a good practice or a legislative...
  8. Boiler1

    Use of bellows for pipe misalignment

    Hi All, Many thanks for all the info! Just to clarify a few of your queries. The system is a machinery coolant, essentially a chilled water & antifreeze solution. As the machinery is quite pressure sensitive, a rupture of this kind means a downtime. So, it’s perhaps rather critical than the...
  9. Boiler1

    Use of bellows for pipe misalignment

    I heave a situation where a bellow is installed to compensate for pipe misalignment. Would this be a common practice? Even without any load in the system the stretch of the bellow it’s clearly visible as the flanges on both sides of a bellow are quite misaligned. My fear is that when the...
  10. Boiler1

    Vaccum pump capacity drop

    Hi. Many thanks for your response. Apologies for delayed follow up. It actually is a liquid ring pump. We only get the high level alarm on the seal temperature and that appears to be OK. Just looked at the impeller. The pump was overdosed with chemicals in the past and received abnormal levels...
  11. Boiler1

    Vaccum pump capacity drop

    Hi, I have got a skid with 4No vacuum pumps connected in parallel operating on duty stand-by basis. All the pumps are being rotated between duty & stand by. Under the normal atmospheric pressure all the pumps operate at more or less same RPM’s, however at the lower atmospheric pressure one of...
  12. Boiler1

    Vacuum pump head vs atmospheric pressure

    You're right! the question is all over the place. Essentially, when the atmospheric pressure drops my system has to start a back up pump in order to maintain the vacuum set point. I assumeed my theoretically feasible vaccum must be somewhere between 0 and the atmospheric pressure. Cant...
  13. Boiler1

    Vacuum pump head vs atmospheric pressure

    Why would the vacuum pump available head depend on atmospheric pressure - i.e. lower the pressure, lower the pump head. If the pump is discharging at the atmospheric pressure can it not create any vaccum on the suction side? Why doesnt such a thing affect the compressors? Regards
  14. Boiler1

    How does one fight complacency in everyday tasks?

    Hello, Lately, for no apparent reason the organisation I’m working at experienced a series of incidents, mainly to human error. It’s the same team, the same procedures in place and yet the focus somehow seem to periodically slip away. None of the incidents had an H&S impact, however all had...
  15. Boiler1

    Flame rod voltage drops after a while - temperature unchanged

    Hi All, I have got a curious situation where on a start-up the burner goes through the normal sequence ( i.e pilot flame followed by the staged flame ramp up) with no issues. After about 15 min. the controller reads the ‘full flame’ or ‘full voltage’ (5V) from the flame rod . The furnace...
  16. Boiler1

    Psychrometric Chart problem

    Many thanks - both of you. BronYrAur - yes you saw correctly what I had in mind.The 'real' cooling process does intersect the RRL. I, sort of, overlooked that. Will have to stop drawing it along the saturation line - only doing it to show the physics behind the drop in moisture content. Regards
  17. Boiler1

    Psychrometric Chart problem

    Thanks GT_EGR, It's mostly re-circulation with some fresh air in - I uploaded the chart above. Regards
  18. Boiler1

    Psychrometric Chart problem

    Hi BronYrAur I uploaded the chart with the process shown. Basically, when the air is cooled down to about the coil temperature (7 °) it ‘drops’ below the RRL. Unless I just stop dropping the air temperature at the point where RRL crosses the saturation line ( around 10° C on the chart). The...
  19. Boiler1

    Psychrometric Chart problem

    Greetings All, In navigating the AHU cycle ( summer) through the psychrometric chart I was always using the method whereby the Room Ratio Line ( RRL) was plotted on the chart to pass through the ‘Room’ point (state) and then the actual ‘Supply Air’ point would essentially be where the RRL...
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