Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

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

Search results for query: *

  • Users: PetroBob
  • Content: Threads
  • Order by date
  1. PetroBob

    Effectiveness of Process Simulators at modelling sour water strippers

    I've been asked to model a sour water stripper that will use natural gas to strip H2S from sour water, using VMG Sim/Symmetry process modelling software. (My company moved away from using HYSYS due to the high cost and insufficient oil industry work in recent years; we only have VMG Sim now.)...
  2. PetroBob

    Stamping non-essential engineering documents

    I'm being asked to provide a professional engineering stamp on non-essential engineering documents such as instrument datasheets, equipment datasheets, etc. I say non-essential, because these datasheets are required deliverables for some projects, but not others. Is this normal or should I push...
  3. PetroBob

    Separation of boiler from human occupied areas, MCC, etc

    Hi, can someone please direct me to the code or standard used in North America to determine where a boiler can be located in relation to a motor control center, and human occupied areas (eg a control room or office, etc). Ie is there a minimum required distance from fired equipment? In this...
  4. PetroBob

    PSV relieving to atmosphere - fire case

    I am being asked to stamp an existing design that includes PSV venting to atmosphere. Relief case is pool fire under the vessel, and hence causing boiling of flammable liquids in the vessel. Liquid Mr = 54, ie heavier than air (although maybe not if hot). I'm accustomed to having PSV outlet to...
  5. PetroBob

    Design pressure of PSV discharge piping

    Our client is insisting that PSV discharge piping must have the same design pressure as the PSV set pressure of 1200 kPag (175 psig). Normally PSV discharge piping would have lower design pressure since it's open pipe to flare, ie pressure is limited to backpressure from hydraulic losses in the...
  6. PetroBob

    Colour used for hand marked updates to engineering drawings

    What colours are typically used for checking and updating process drawings? What about other engineering disciplines, eg civil drawings? Typically companies I've worked with use red for additions, green for deletions and blue or black for comments (that are not CADDED). This is for hand...
  7. PetroBob

    Bottled nitrogen cooling due to JT effect

    We are letting nitrogen down from high pressure cylinders at 4250 psig / 29,300 kPag, to just above atmospheric. The nitrogen will be used to purge piping and equipment. I understand that the nitrogen will get very cold due to JT cooling. HYSYS gives very alarming temperatures; eg if bottles...
  8. PetroBob

    Does a methanol tank need a flame arrestor?

    A 9000 gallon methanol tank located at an oil & gas facility, would you, or would you not include a flame arrestor on the tank vent? All instrumentation will be Ex rated. I believe the only potential source of ignition would be lightning strike.
  9. PetroBob

    Methanol Tank Materials of Construction

    For a 9000 gallon methanol tank located at an oil & gas facility, what materials are recommended and why? We are considering carbon steel, or coated carbon steel. Apologies for the simple question - I am not a materials engineer.
  10. PetroBob

    Shell & Tube Exchangers in Series

    We are proposing to install a new shell and tube exchanger physically close to an existing shell & tube exchanger. Both existing and new exchangers use hot glycol solution to heat process water. The existing exchanger #1 has a high enough glycol discharge temperature to serve as inlet to new...
  11. PetroBob

    Rule of Thumb for estimating number of engineering deliverables

    What are typical rule of thumb ratios that experienced engineers use when calculating number of deliverables for a process design? For example, if you know the approximate number of PFDs in a typical plant, how do you ratio to estimate of number of P&IDs, lines, major equipment, instruments...
  12. PetroBob

    Methanol Fuel Cell or Solar vs diesel generator

    We're considering a methanol fuel cell or perhaps solar panel system as alternative to a diesel generator for a remote site. The power is required for a small amount of instrumentation (eg pond level control, etc), hence only a small load. For larger loads we'd use a diesel generator. But it...
  13. PetroBob

    Conductance switch for pump level control

    A pump supplier is suggesting we use a conductance switch - eg Warrick type - for pump on/off actuation. I'm not personally familiar with this type of pump actuation and would like to know whether conductivity based liquid level control is used often, and in what applications? The pumps are...
  14. PetroBob

    Pipe size range for ASME B31.3

    What is the largest pipe size for which B31.3 applies?
  15. PetroBob

    Options for hot water energy recovery

    I've been asked to generate innovative options for recovering energy from hot frac flowback water (on wellpad). Water flowrate is dropping exponentially from initial startup, but flowrate will spike back up again when new wells are brought online. Ie there is huge variability in flow. We don't...
  16. PetroBob

    Professional engineering stamp for generic design

    I've been asked to stamp process documents (PFDs and P&IDs) for a generic plant design, ie several of them may be built at different locations in accordance with the PFDs and P&IDs I'm signing off. Perhaps this is more common in other engineering disciplines but this is the first time as a...
  17. PetroBob

    Need ideas for large heat exchanger for natural gas

    I need to come up with a suitable heat exchanger(s) for ~30 MMBtu/hr (8.5 MW). We prefer to use electricity not fired heater if possible. Service: Warming ~100 MMSCFD of natural gas at 3300 psig from 77 degF to 185 degF. Can anyone recommend possible heat exchanger types for this service...
  18. PetroBob

    FPSO - types of heaters

    I'm doing a feasibility study for a novel marine process that has some similarities to FPSO. I haven't personally worked on FPSOs before, so was hoping to get some guidance from engineers more familiar with FPSO design than I am. What types of process heating systems are typically used on an...
  19. PetroBob

    Does HYSYS give viscosity errors blending heavy & light hydrocarbons?

    Hi folks A HYSYS simulation for blending diluent and bitumen is showing lower kinematic viscosity in the dilbit than that actually measured in the field. Is this a typical error for HYSYS? (Ie is it normal for HYSYS to under-predict viscosity when blending light and heavy hydrocarbon liquids?)...
  20. PetroBob

    HYSYS viscosity error for diluted bitumen

    Hi folks A HYSYS simulation for blending diluent and bitumen is showing lower kinematic viscosity in the dilbit than that actually measured in the field. Is this a typical error for HYSYS? (Ie is it normal for HYSYS to under-predict viscosity when blending light and heavy hydrocarbon liquids?)...

Part and Inventory Search