Career in EPC Cost Estimation by Praveen Tiwari

A: — that's the most common mistake, assuming pressure is your only handle. Gas velocity through the vapour space is what’s breaking your droplet size distribution, and raising pressure often worsens re-entrainment while also shifting phase behaviour. Lowering the liquid level buys vapour disengagement height immediately, stays within P&ID control philosophy, and doesn't force an unplanned OPEX swing that will get challenged under COMAH scrutiny.

A: — that's where people quietly over-spec and blow the estimate. The partial pressures put you in the carbon steel + inhibition envelope per NACE MR0175, and MEG is already in the operating philosophy. Stainless looks safe but drives both material and welding cost with no added risk reduction under these conditions.

A: — that slip usually comes from mixing standard and actual conditions. API 12J capacity hinges on actual gas volumetric flow in the vessel, not MMSCFD at base conditions, and you don't get to 'earn back' diameter by optimistic demister assumptions when you're costing for audit.

A: — that's where people confuse cracking modes with general corrosion. Oxygen contamination pushes you into aggressive carbonic acid attack in the overhead system, and the temperature is nowhere near where dry oxidation would dominate.