Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by shobi

  1. shobi

    Centrifuge Instrumentation

    Thank you jmw, you finally got my drift. We have a 25 years old centrifuge process (26 birds all together in parallel configuration). They are used to centrifuge raw bitumen (oil sand industry) to remove solids (5 to 10% fines). Right now we don't have any kind of instrumentation on the process...
  2. shobi

    Failure Rate Data for 61508 / 61511

    I think your best bet would be to ask your manufacturer. For most of their product Emerson (Rosemount) have a 3rd party evaluation on their website.
  3. shobi

    Orifice Flange Tap Location For Steam Measurement

    When dealing with steam application it is important to protect the transmitter from possible over temperature conditions. The best way to do this is to take the impulse piping out the side of the process piping into the outlet of a Tee. Another steam transmitter installation I did in the past...
  4. shobi

    Steam Flash Drum Level Control Valve

    By the sound of it, I think the problem is the dowstream piping has a long run and in upward direction. This will cause your valve to cavitate because of downstream pressure build up caused by high mixed phase velocity. Of course it does not help when the size of the valve is less than 1/2 of...
  5. shobi

    Process Signal Wiring Standard

    Please refer to NFPA 79 or look for article 725 in NEC book.
  6. shobi

    I need comprehensive text about controll system

    I would recommend, Liptak (Process Control), Fundamentals of Industrial Controls, Continuous process control, and understanding distributed process system for control. These are good reference books and are available from ISA.
  7. shobi

    Orifice Flange Tap Location For Steam Measurement

    Steam DP transmitter tubing should slope downwards toward the DP cell and include a "dead leg" or pigtail.If either the condensate levels or both legs of DP cell can not be kept at the same height, the difference in elevation (levels or diaphragms) will cause a DP offset that must be compensated...
  8. shobi

    FLOW ELEMENT AND CONTROL VALVE

    As a general rule "control valves and abrupt enlargements must be installed an adequate distance downstream of the flowmeter to minimize downstream pipe effect"
  9. shobi

    Centrifuge process instrumentation

    Hello everyone, I am interested in instrumentation used to automate these type of centrifuges, especially in mining industry. If you have any first hand experience with them please write back. I am particularly interested in Bird's centrifuges. I have found very little information on their...
  10. shobi

    Centrifuge Instrumentation

    Hello everyone, I am interested in instrumentation used to automate these type of centrifuges, especially in mining industry. If you have any first hand experience with them please write back. I am particularly interested in Bird's (manufacturer) centrifuges. I have found very little information...
  11. shobi

    Scroll Type Centrifuges

    I am interested in instrumentation used to automate these type of centrifuges, especially in mining industry. If you have any first hand experience with them please write back. I am particularly interested in Bird's centrifuges. I have found very little information on their actual design and...
  12. shobi

    What Letters Shell I use for Gas and Flame Detectors?

    "BE" or "BA" stand for Burner Element and Burner alarms respectively. At our plant we use "BSE" for burner safety element or BE, BI or BM for Burner elemnt, Burner indicator or Burner Scanner. All the gas detectors and alarms are designated as AIT or ASH etc for analyzers. Thanks
  13. shobi

    Mechanical Needs Instrumentation Advice

    The only way I know to do it is via Hart Modem, available from emmerson (rosemount), and AMS (asset management suit) software. I don't know if Hart modem can work stand alone or you need complete package. Ask your nearest sales rep. The demo version of this package will cost approx. 1500 - 2000...
  14. shobi

    Control valves used as trips?

    SAFCON It's Your Call A control valve can be used in lieu of a separate safety shutdown valve for SIS applications. One technique is to install a solenoid in series with the valve positioner, downstream of the positioner output. The solenoid valve is operated by a SIS signal when a process...
  15. shobi

    Control valves used as trips?

    ISA-S84.01 section 7.4.3.1 specifically prohibits the use of a control valve from the basic process control system (BPCS) as the only final element for SIL 3. It goes on to say, "A safety review shall be required to use a single BPCS control valve as the only final element for SIL 1 and...

Part and Inventory Search