As per the PFDs, a mixture of sour water and 50% hydrocarbons enters a three-phase separator operating at 185 psig and 120°F. The separator is provided with an LCV to control the liquid level. This LCV also reduces the pressure of the sour water from 185 psig to atmospheric pressure.

After separation, the sour water, containing 0.12 mol% H₂S, is routed to an atmospheric storage tank (internal floating roof tank) through an 8-inch line. The tank is provided with an 8-inch water inlet nozzle, which is submerged below the liquid level. The minimum tank liquid level is 4 meters, while the tank is 18 meters high and 15 meters in diameter.

The tank is equipped with a PVRV designed for thermal breathing. An H₂S adsorbent bed is installed on the tank vent line to treat the vented vapor before discharge to the atmosphere. The tank is also provided with nitrogen blanketing to maintain the required tank pressure.

The tank is an internal floating roof tank. The design sour water flow rate is 6,000 bbl/day, while the actual operating flow rate is approximately 2,000 bbl/day.

Appreciate any major concerns with this design. The project is about to start based on the provided design by the engineering contractor.

The curve may still be perfectly useful, but you're left with a scanned or paper Q-H curve rather than a digital dataset.

Curious how others here deal with this:

• Do you digitize the curve manually and recreate the Q-H data in Excel or another tool?

• How do you handle interpolation between the published points?

• When the operating conditions change, how do you generate a revised curve using speed or impeller diameter changes?

• For old curves, how do you handle efficiency and NPSHr data when only the original plotted curves are available?

• For pumps in series or parallel, do you digitize and combine the curves yourself?

I've ended up building an Excel workbook for my own work that takes a pump performance curve from a paper/PDF/image source, converts it into a usable digital curve, and then allows the curve to be evaluated under changed operating conditions using the relevant scaling relationships. It also allows the resulting performance data to be generated in a usable engineering format.

The reason I built it was mainly to make older or otherwise inaccessible pump curves usable again — particularly where the original OEM digital selection software or product database is no longer available.

Happy to share what I developed if anyone is interested. I'm mainly interested in how others here approach this problem and whether there are established methods or tools that you use.

I am sizing a PSV attached to a TEG filter, where the selected overpressure scenario is Fire Case. There are several heat and material balance (HMB) cases, which have varying operating conditions and fluid properties. Just for the sake of comparing I have run all cases with the reference stream taken at the inlet of my vessel. The results are as follows. My question is, how would I know how to screen for the HMB cases in order to get the maximum relief load and/or orifice area? By the trend in the table below, it seems that the maximum relief occurs with the case which has the highest overall MW and highest liquid fraction. Is this always the case? Are there any other fluid properties which I must look for in order to determine the governing HMB case?

 Hydrate_Prediction_Calculator_Wayne Gajadhar.xlsx   128.5KB   13 downloads

Hi Forum,

I would appreciate your views on the appropriate discharge location for PSVs installed on a Heating Medium (Hot Water) System, which includes equipment such as expansion vessels, filters, heat exchangers, and associated piping.

Although the heating medium system is designed as a closed-loop circuit, there is a foreseeable risk of hydrocarbon contamination due to potential leakage across heat exchanger tubes or other exchanger failures. In such a scenario, the heating medium could become contaminated with process hydrocarbons.

Considering this possibility, I am evaluating the PSV discharge philosophy and would like to understand whether routing the PSV outlets to the flare header would be the preferred design approach for all PSVs associated with the heating medium system, rather than discharging to atmosphere or a safe drain system.

Could you please share your experience and recommendations regarding:

• Typical industry practice for heating medium hot water systems.
• Criteria used to determine whether PSV discharge should be routed to flare.
• Considerations related to hydrocarbon contamination risk, environmental requirements, and operational safety.
• Applicable standards or project-specific philosophies that influence this decision.

Thank you in advance for your insights.

Best regards,
Dhams

I am calculating the actual temperature of the flaring gas from our Vacuum Distillation Tower where a stream of gas (C11H24) at a temperature of 400 C, a pressure of 4.5 barg, enters a flare header with a diameter of 32 inches and a length of 600 meters. Given that the ambient temperature is 48 C, according to heat transfer calculations, on average, the gas temperature drops to 340 degrees at the end of pipe. But this temperature for stress analysis calculations has led to the addition of several loops in the design. Does anyone have any experience in this regard? Isn't the temperature of the pipe wall much lower in practice due to the actual heat transfer with the environment as well as radiation, for example, below 200 degrees? If the temperature drops more in practice , the number of loops caused by the stress analysis calculations will really decrease. I would like to thank you for helping me.

Araboni

SO BASICLY WE WANT TO SIZE A PRESURE EQUALIZATION LINE FOR A 10" PIPELINE VALVE (KIND OF BY-PASS) TO EQUALIZE THE DOWNSTREAM OF THE 10" VALVE DE TO A VERY HIGH DP BETWEEN UPSTREAM AND DOWNSREAM OF THE VALVE.

THE PIPELINE CARRY A 85 BAR LPG.

The Process parameters are as follows

Flow: 10700 usgpm (Fluid: Water)

Temp in / out : 3.3 / 13.3 C

Internal tank dimensions : 14 m x 14 m x 42.5 H

There could be an H shaped or a octagonal shape diffuser with slots. The length of the diffusers (top and bottom) can be adjusted.

I need advise from fellow engineers, if any one has any calculation/references to calculate the dimensions of the slots (WxLxDepth), in-order to maintain very laminar flow/low velocity so that the thermocline thickness is not disturbed through out vertical length while charging and discharging. Or there is a dimensionless number such as Froude no or so which can relate to the slot design.

Thanks

Instrument air dryer uses adsorbent  Alumina for removal of moisture designed for 100 % humidity & 45 Deg C  With lower humidity and feed temperature at 35 Deg C whats is impact on performance respect to dew point and capacity of the dryer. 

With regards

In our product transfer unit TSV are provided on transfer lines from Tank to loading bay. TSV set pressures 12 bar are observed to match the pumps shut off pressure when operated at minimum flows.Now we need to reset the TSV set pressures,as observed frequent activation leading to maintenance.Whats should be the revised TSV pressure .considering no change in pump operation. 

Thanks 

Do you have experience with vibrational viscometers like the ones here from Rheonics: https://rheonics.com/solutions-item/meeting-rigorous-quality-control-of-asphalt-for-every-load-at-the-terminal-with-real-time-viscosity-measurements/

What else have you used? 

For the nitrogen flow measure ment we have DP type transmitter having range 0-2500 MMWC ,variance ,diff between custody meter which is ultrasonic  is observed at a lower flows < 1000 Nm3/hr . With current DP what are the options for reducing the difference