Engineering Facilities interview prep.

Facilities engineers, project engineers, pipeline + station design leads, compressor + pump engineers, terminal + LNG facility engineers, integrity engineers on capital projects.

What interviewers look for

  • Can the candidate design pipelines + stations per ASME B31 + API + PHMSA codes (192 / 193 / 195)?
  • Do they have hydraulics + compression / pumping fluency - sizing, MAOP, NPSH, head + power calcs?
  • Are they fluent in FEL / FEED / detailed-design stage-gate discipline + AFE cost + schedule control?
  • Can they navigate HAZOP + LOPA + PSSR + safety-in-design + 1910.119 / RMP boundaries?
  • Do they understand materials + corrosion + cathodic protection + integrity considerations from design forward?
  • Are they grounded in commissioning + handover to ops + start-up safety?
  • Long-game fit - project engineer / lead / senior / principal / engineering manager trajectory?

Behavioural questions to expect

  1. Walk me through your background + engineering + project experience.

    What it tests: Story arc - training, design + project experience, safety + regulatory exposure - so the interviewer can place you on the FEL/FEED/detail/construction spectrum.

  2. Tell me about a design or capital project you've led or been part of.

    What it tests: Engineering rigor - design discipline, cross-discipline coordination, project economics, safety integration.

  3. Why midstream engineering vs upstream / downstream / chemicals?

    What it tests: Authentic alignment - infrastructure permanence, design + integrity discipline, project execution rhythm.

  4. Why this asset type - liquids pipeline / gas transmission / compressor + pump station / terminal / LNG?

    What it tests: Specificity. Generic 'I like midstream' answers fail. Asset type + code regime differ materially.

  5. Why this firm?

    What it tests: Real homework - assets, capital programme, engineering model - not name-drop.

  6. What's your read on our asset footprint + active capital programme?

    What it tests: Industry literacy - asset mix, recent + planned projects, FERC + PHMSA posture.

  7. Tell me what you understand about how we execute capital projects.

    What it tests: Engineering-model fluency - self-perform vs EPC, FEL discipline, recent on-time / on-budget track record.

  8. Walk me through a major design decision you've made on a pipeline, station, or facility.

    What it tests: Design fluency - code interpretation, materials + sizing + safety trade-offs, decision authority.

Technical concepts to master

Pipeline + facility design

Design basis + Class 1-4 (gas) / High-consequence routing
Foundational design document - product, MAOP / MOP, design factor, location class, route, ambient + soil conditions.
Wall thickness + materials selection (Barlow + API 5L)
Wall thickness from Barlow formula given pressure, diameter, SMYS, design factor; materials chosen for service + cost.
Compressor + pump station layout
Station layout for gas (centrifugal / reciprocating compression + driver + cooling + scrubbing) or liquids (centrifugal / PD pumping + filter + meter).
Cathodic protection + AC mitigation
External corrosion control - impressed current + galvanic CP per NACE SP0169; AC mitigation where pipelines parallel HV powerlines.

Hydraulics + compression + pumping

Steady-state hydraulics
Pressure + flow + temperature profile along pipeline at design conditions - drives compressor + pump station spacing + sizing.
Transient + surge analysis
Dynamic pressure response to valve closure, pump trip, compressor trip - waterhammer + surge mitigation design.
Compressor sizing - polytropic head + power
Polytropic head from inlet / outlet pressure + temperature + gas properties; brake power = head x mass flow / efficiency.
Pump sizing - TDH + NPSH
Total Dynamic Head from suction / discharge / friction + static; NPSH available > NPSH required to avoid cavitation.

Project stage gates + AFE discipline

FEL 1 (Appraise / Concept)
Concept screen - business case, asset class, rough capacity, order-of-magnitude cost (-30 / +50%).
FEL 2 (Select)
Concept selection - preferred option, basis of design, preliminary layout, AACE Class 4 estimate.
FEL 3 / FEED (Define)
Front-end engineering design - detailed basis, P+IDs, equipment list, AACE Class 3 estimate (-10 / +25%).
AFE (Authorisation for Expenditure)
Capital project funding request - scope, cost, schedule, economics, risk - approved before construction sanction.

Safety-in-design + commissioning

HAZOP (Hazard + Operability)
Systematic guide-word review of design - node by node, parameter by parameter (more / less / no / reverse) - identifies hazards + operability concerns.
LOPA (Layer of Protection Analysis)
Semi-quantitative analysis - scenario frequency x consequence vs target risk; IPL credits reduce frequency.
SIS + SIL (Safety Instrumented Systems / Safety Integrity Level)
Safety Instrumented Systems with SIL 1-3 rating per IEC 61511 - PFD avg target by SIL level.
PSSR (Pre-Startup Safety Review)
Formal verification before hydrocarbon introduction - built per design, procedures in place, training complete, PHA actions resolved.

Practical drills

  • You're sizing a 50-mile natural gas transmission line, 24 inch nominal, MAOP 1440 psig, Class 2 location, API 5L X65. Walk through wall thickness selection, hydraulic profile considerations, and one or two key trade-offs.
  • You're leading a HAZOP for a new compressor station - one node is the discharge of a centrifugal compressor. Walk through how you'd identify hazards + apply LOPA for one high-consequence scenario.
  • You're 70% through FEED on a new LNG truck loading facility. Operations team requests adding a third loading bay (originally two-bay design). Walk through your decision.

Smart-question anchors

  • Asset footprint + active capital programme - announced projects, FERC certificates
  • Engineering execution model - in-house vs EPC, FEL discipline maturity
  • Recent project track record - on-time / on-budget, lessons-learned commentary
  • Design + integrity choices - coatings, CP, AC mitigation, high-strength steel use
  • Regulatory engagement - PHMSA design, FERC, state PUC, environmental permitting

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