Hi.
Would you please help us about technical problem we encountered?
In attached PFD, during normal compressor shut-down operator increases opening of 05-330-FV-015 and 016 (1st and 2nd stage compressor anti-surge valves) and at the same time decreases compressor speed.
When anti-surge...
Dear all.
Hello.
I have a question. would you please help me?
Normal/min/max steam temperature to the steam turbine is 410/400/430 C (pressure: 40 barg). But right now inlet steam temperature is 360C!!! due to operating limitations.
What is the mechanical and operating effects of this...
Hi.
My last post has been deleted!!!
Here is my question.
N2 fail mode is fail open. Suppose the power unit fails, so all control valves fail to safe mode and n2 control valve open completely and drum pressure reaches 8 barg.
Could we change fail mode of n2 control valve to close? (In order to...
Dear all. Hello.
Why in most industrial plants, cooling water vlave of heat exchabger is manual (non control valve)?
I think we can conserve lots of e energy using regilation of cooling water flow through heat exchanger in different plant load
Dear all.
Hello.
Due to tube failure of heat exchanger, methane gas enters into water cooling. We are going to measure the gas component in water to ensure tube failure.
Unfortunately LAB section is not able to determine gas content in water in this way.
We are considering to flash water stream...
Dear all.
Hello.
I have a question. Would you please help me?
We want to storage and transport methanol for a short period of time (loading from one tank and unloading to the other tank- distance: 500 m). Currently we are using plastic container.
Is there any safety guideline in NFPA or other...
Hi everyone.
I have a question.
Our Coldbox vendor provided two variables for natural gas stream enter the coldbox:
1- Calculated pressure drop: 0.3 bar
2- Allowable pressure drop: 0.4 bar
Don't you think the gap between two variables and also the second variable value is very low?! According...
Dear all.
Hello.
I have a question.
In attached process data sheet, design temperature of ethylene storage tank is -40 C, and depressurizing temperature is -89 C. But the designer selected LTCS (with minimum temp.: -45C) and noted that this material should sustain depressurizing condition!!! How...
Dear all.
Hello.
I have a question. Would you please help me?
In attached shell and tube twin parallel heat exchanger, Natural gas (NG) enters in tubes and propane enter in shell. Although both exchangers are completely the same, but propane level in exchangers are not equal, So the PRP-out...
Hi everyone. I have a question.
In our fractionation plant, LPG stream is desulphrized in reactors and then headed to depropanizer and debutanizer towers where C3 and C4 will be recovered.
When we put fresh reactor in service, total Sulphur in C4 increase drastically while total Sulphur in C3...
Dear all.
Hello.
I have a question.
We have a steam turbine which operated with high pressure steam (HPS). Min and Max pressure and temperature of HPS inlet is given in Vendor catalogue (min P= 39 barg, Max P=41 barg) (Min T=390 C and Max T=410 C).
Unfortunately HPS operating condition...
Dear all Hello.
I have a question. Would you please help me?
What is the effect of presence of methanol in ethane feed to olefin plants?
And what is the maximum permissible methanol in ethane feed?
thanks in advance...
Dear all.
HELLO.
I have an issue.
As illustrated on attached picture, liquid ethane is warmed and by thermosyphon mechanism, two phase ethane goes back to circulation drum.
Unfortunately U-type piping right after cold box is done, so it has a negative effect on thermosyphon moving and during...
Hello all. I haven't seen any compressor topic!. So i post my question here.
After ethane compressor start up, lube oil supply pressure to compressor and electric motor bearings all decrease suddenly (from 1.2 barg to 0.5 barg), so we have to increase them up to the normal values.
Likewise...
Dear all. Hello.
Have you ever heard about boxed-up format, which is completed right before closing the manhole of an equipment's?
During overhaul, some of the equipments has been opened and cleaned and then after checking all of the internals, a check-up format is completed and then manhole...
Hi.
I have a question.
We have a 36000 m3 propane storage tank. Initial tank conditions is as follows:
T=20 C
P=0 barg.
We are going to cool down the tank to -44 C using liquid propane at -44 C. How much propane required?
thanks in advance.
Hi.
I have a question, would you please help me?
We have already installed vessel, which unfortunately doesn't have any vent nozzle!. Is it possible to make a hole on top of the vessel, and weld an olet???
Is there any standard related?
Hi.
I have a question. would you please help me?
We have a LPG off-spec tank, during upset condition Propane and Butane is sent to this tank for further reprocessing. Tank Pressure control is done using methane at 30 barg (as illustrated on picture). Here is the question.
When we reprocess...
Dear all. I have a question. Would you please help me?
In our propane storage tank (T=-44 C, P=4 mbarg), sometimes CH4 enters so it build up in condenser of propane chilling system and flaring is done by operator in order to reduce pressure of chilling compressor discharge.
How can I calculate...
Hi everyone. I have a question. Would you please help me?
On the attached PFD, we have a circulation drum (310-V-4) which transfer and get refrigerant ethane to/from coldbox heat exchanger.
In the case of accidentally closing of PV and LV, all liquid ethane in circulation drum could vaporize...
