• Isomerization reactor 037-RB-001, 037-RB-002 and 037-RB-003 shall not be located in the fire zone of stabilizer 037-CC-001.
• Isomerization regeneration section shall be located as close as possible to dryers section.
C2Cl4 is not flammable. Fire around C2Cl4 storage can only result from an external process fire. C2Cl4 storage area should consequently be located outside and preferably upwind of the process area that can be affected by a fire.
Furthermore, C2Cl4 storage area should be surrounded by a small wall to contain possible spills of C2Cl4 (to be adsorbed by an inert material).
This wall will also impede propagation of a process fire towards C2Cl4 storage tank. The location of this wall can be located at 30 meters from the drainage point of the paved process area where a process fire can occur.
In these conditions, the C2Cl4 storage area may be considered in a fire safe area. This does not exclude the fact that C2Cl4 storage should be reached by water for fire fighting equipment to cool it down during an external fire.
21.0
Special Design Requirements
• In case of motor operated valves, (critical service) indication of valves position should be available in the control room. Shut-down valves should be operable from the control room.
• The blow-down from stream drum if any should be routed to storm water sewer after cooling it. Use of blow-down from the steam generators of Hydrogen Unit to the extent it is possible within the unit. Excess quantity, if any, should be drained to storm water sewer after flashing and cooling in a blow-down drum.
• Instrument and electrical cables shall be above ground and under ground respectively inside the unit battery limit.
• General HAZOP analyses should be considered in the design of the unit.
• Furnace with 8-10% excess air.
• The following non-standard line sizes shall not be used unless approved by PMC-¼”, 2½”, 3½”, 5”, 7”, 9”
• The following guidelines for minimum line / nozzle sizes shall be applied – 2” NB Minimum nozzle size for vessels, tanks and heat exchangers 2” NB Minimum process (hydrocarbon) line size
1½” NB Minimum utility line size
¾” NB Minimum bridle drain or pump casing vent / drain
½” NB Minimum chemical injection line size. Tubing size to be 10 mm 1½” NB Minimum on pipe rack
4” NB Minimum for underground lines
• The following roughness coefficients shall be used unless stated otherwise –
Material Roughness (inches)
Carbon Steel 0.0018
Flare / Vent headers (Heavily corroded) 0.018
Stainless Steel Pipe 0.001
Glass Reinforced Epoxy Pipe 0.0001
• A margin of at least 0.6 m between NPSH available and required NPSH shall be applied. In case of requirement of lower difference, concurrence of PMC/IOC is to be obtained.
• NPSH test shall be performed where ever the difference between NPSH available and NPSH required is less than 0.9 m.
• Vents & Drains in Heat Exchangers
Provide 1” NB x 300# (min.) flanged vents and drains at high and low points respectively on all heat exchangers. All vents and drains shall be valved and blanked off.
Exchangers in total condensing service shall be provided 2” vent connection at the opposite end of the shell inlet.
Sizes of multi-purpose connections and pressure gauge connections on exchanger nozzles shall be 1” NB x 300# (min.) for below 12” nozzles and 2” NB x 300# (min.) for 12 “ & above nozzles.
• Vents & Drains in Piping
Pipe Size in Inches Vent Size, inches Drain Size, Inches
4 & below ¾ ¾
6 to 10 ¾ 1
12 & above 1 1½
• Vents & Drains in Air Coolers
On air coolers, one no. 2” vent shall be provided at the highest point on the inlet header and one no. 2” drain at the lowest point in the outlet header. These connections shall be valved and blanked off.
• Vents & Drains in Pump Casing
For non-volatile services, casing vents and pump drains shall be piped into a sewer or closed drain system.
For volatile services, casing vents and drains are to be piped to the relief header and sewers.
• Double Block Valves Philosophy
Double block valves shall be provided for the following conditions – For cases where cross contamination can’t be tolerated.
For vents and drains in ANSI Class 600 rating and above
For drains containing C5 or lighter hydrocarbons. In this case, the double block valves must be minimum of 1000 mm straight pipe apart.
Where high pressure (above ANSI 300# rating) is likely to be removed on the run; e.g. spare machinery or equipment
For gas stream > 100 bar g or liquid systems > 60 bar g or gas/liquids which are potentially toxic.
For the equipment, which may be opened for maintenance on the run e.g. filters.
• Fire proofing shall be carried out as per OISD-164.
Note:
1. PMC should develop a feed scheme for the MSQ Unit as per discussion with IOCL as there will be some variation from what has been proposed by Axens in the Process Package.
2. Specifying all speciality items identified or implied in process package such as strainers, filters, steam traps, flame arrestors, special purpose valves, heat exchanger isolation valves with blinding provision, Instrument tapping isolation valve, pump/heat exchanger drains to CBD/OWS, control valve upstream & downstream side bleeders, sample points in CW return line, feed & product rundown lines.
3. Installation of Gas Detectors as per OISD/ CCTV/Pegging System/ Fire Water & Foam Network as per OISD, Fire Alarms etc for safety of the equipments & the units.
4. Sight glass may be provided in the drain to CBD lines. CBD/OWS system may be designed as per advice of PMC/Owner.
5. Flare & Fuel gas (with KODs) network is to be developed. All field Instruments shall be suitable for zone 1, IIC T3 shall be certified by a statutory body with gas grouping as per requirement.
6. Steam silencers with proper design are to be provided.
7. Automation (Sequance Logic Diagramfor pumps & dryer operation, will be developed and implemented.
8. For reciprocating compressors, 2out of 3 voting system to be incorporated for important interlocks such as vibration interlock.
9. Provision of DM water to be kept instead of Cooling Water for Compressor seal, Gear Box, Cylinder jacket cooling etc.
10. Critical rotary equipment running signal to be provided at DCS
11. Utility connections to all Heat Exchangers/ Vessels/ Columns are to be provided for flushing. Steam flushing in Isomerisation section is to be avoided..
12. Back flushing facility in water side in all water coolers to be provided. 13. Condensate Recovery network is to be developed.
a.Process assistance in development of PRDS and Steam de-superheater for 3 Bar steam from 10 Bar steam
b.Steam (MP/IP/LP)/ BFW/DM Water/ Instrument Air/Plant Air/ Cooling Water/ Service Water/ Drinking Water/ Hydrogen gas/ Nitrogen Gas distribution networks are to be developed.
c. LICENSOR has recommended MOCs in equipment datasheet. However, the MOCs of all critical equipments which are subjected to corrosive service are to be cross checked and confirmed.
14. Packages e.g Compressor with interstage KOD/s & Intercooler/s and other associated facilities like lube oil system, cooling system, instrumentation & control philosophy with selection of proper unloading technology, start-up ejector system, HDT fired heater with auxiliary facilities inclusive passivation facility for heater tubes & flue gas analyzer, sulfiding agen (DMDS) injection & passivation package, corrosion inhibitor (CHIMEC 1044) injection package, chloriding agent (C2CL4) injection package, caustic solution preparation package, dryer package, electrical heater with auxiliary facilities, steam condensate pots & accessories, analyzer package, Ammonia & HCL dosing package etc Process interlocks/instrumentation linked to central control room for operator interface are to be indicated.
15. Utility connection to be provided to Vessels/ Columns for flushing. Steam flushing in Isomerisation section is to be avoided. Vessel isolation system, drain points and utility connections are to be shown in upgraded P&IDs.
16. All Heat Exchangers isolation system, drains at both ends i.e tube side as well as shell side & utility connections are to be provided in upgraded P&IDs.
17. Analyzer package for analyzers if required like Oxygen analysers e.g Orbisphere 410. 18. Flare Load Summary: PMC shall check the adequacy of flare header.
19. Details for package items like Feed Filter, Compressors Package, Fired Heater Package, Electric Heater Package, Sulfiding Agent Dosing Package, Corrosion Inhibitor Dosing Package, Chloriding Agent Dosing Package, Dryer Package, Steam Condensate Recovery Package including condensate pots, Analyzer Package, Caustic Solution Preparation Package, Ammonia & HCL Dosing Package Prefilter – Coalescer, Ejector, etc to be developed by PMC/LSTK.
Index of Revisions
Rev. Sheet Prepared, revised Checked Approved Remark, kind of revision
Name Date Name Date Name Date Status
00 ALL CS 24.12.07 TSM 26.12.07 SMK 26.12.07 IFC Issued for Comments