Project Nº.
R202-00 Revision B1
SEA WATER R.O.-4 POTABLE
Project Title. Page 18 of 23
WATER, JUBAIL
Document Nº. R202-00/P.02a/0002 Date 3 Jun 2010
4.8 PIPING SYSTEMS
Pressure profiles and line sizes will be calculated at 100% of design flow.
4.8.1 LINE SIZING CRITERIA
LINE SIZING CRITERIA FOR LIQUIDS
SERVICE LINE SIZE MAXIMUM PRESSURE
VELOCITY DROP
Normal Max.
(in) (m/s)
(bar/100m) (bar/100m)
Pump suction, bubble point ≤2 0.6 0.06 0,09
(1) 3 ≤ - ≤ 10 0.9 " "
12 ≤ - ≤ 18 1.2 " "
= > 20 1.5 " "
Pump suction, subcooled ≤2 0.9 0.23 0.35
3 ≤-≤6 1.2 " "
8 ≤ - ≤ 18 1.5 " "
= > 20 1.8 " "
Pump discharge, P < 50 bar g ≤8 2.5 0.35 0.45
10 ≤ - ≤ 12 3
14 ≤ - ≤ 16 3.5
Pump discharge, P > 50 bar g 18 ≤ - ≤ 24 4 (3) 0.7 0.9
Reciprocating pump
Suction 1
Discharge 2
Gravity flow 0.6 0.025 0.045
Thermosiphon reboiler (5) 0.02 0.04
Side-stream draw-off (2) <2 0.6 0.06 0.09
>3 0.9 “ “
Hydrocarbon liquids 4.6
Rich amine
Carbon steel 1.1
Stainless steel 1.5
Caustic soda 2.0
Acid (HCl) 1.6
Lean amine 2.0
Stripped sour water 2.0
Sour water 1.5
Cooling water / Service water 3.0 0.15 (6)
0.23 (7) 0.35 (7)
BFW, DMW, Process water, 3 to 4 0.35 0.45
Potable water
Notes :
(1) Also applicable to liquid containing dissolved gas (except for 12 in – 18 in: 0.9 m/s max).
(2) Provide a vertical run of 3 meters minimum from nozzle, at nozzle size, before reducing the size of the line
(3) Up to 5 m/s for big lines
(4) For loading line, velocity can be increased up to 5 m/s. Before 50 to 100 m of upstream the tank inlet, the velocity shall be
reduced to 1 m/s to limit risks associated with static electricity.
(5) To be checked by Heat Exchange Design Engineer
(6) For long headers
(7) For short lines
(8) Reference is made to Saudi Aramco Engineering Standard SAES-L-132 for everything that is not covered by above table
Project Nº. R202-00 Revision B1
SEA WATER R.O.-4 POTABLE
Project Title. Page 19 of 23
WATER, JUBAIL
Document Nº. R202-00/P.02a/0002 Date 3 Jun 2010
LINE SIZING CRITERIA FOR GASES AND STEAM
SERVICE PRESSURE LINE SIZE MAXIMUM MAXIMUM PRESSURE DROP
VELOCITY ρV2
Normal Max.
(barg) in (m/s) (kg/m s2)
(bar/100m) (bar/100m)
Gases (general) (1) P < 20 35 10 000 (3)
20 < P < 50 35 10 000 (3)
50 < P < 80 35 14 000 (3)
P > 80 30 14 000
Column ovhd 25 10 000
Air/nitrogen <20
Flare lines 0.4 Mach 25 000
(4)
0.3 Mach
Compressor suction
Reciprocating 10 3000 0.02 0.07
Centrifugal 10 6000 0.05 0.12
Compressor discharge (5) 0.04 0.115
Steam, saturated (6) <2 10 10 000 (2)
3-8 30 "
> 10 40 "
Steam, superheated (1) (6) <2 10 10 000 (2)
3-8 40 "
> 10 50 "
Notes :
(1) Updated maximum velocity requirements due to gas lines mostly being operated in a saturated condition.
The above indicated line sizing criteria are valid for continuous operation. In that case, the pressure drop in bar/100m
shall be less than 5% of the static absolute pressure for long headers and 10% for short headers. For intermittent
operation, these limits may be exceeded on a case by case analysis.
(2) ρV2 limit of 10 000 can be increased to 25 000 for steam let down stations
(3) Indicative value. Do not exceed 14 000
(4) 0.3 Mach for subheaders, 0.4 Mach for main headers
(5) Compressor vendor requirements, if any, will prevail
(6) Maximum velocity for steam:
P < 5 barg 30 m/s
P = 5 - 20 barg 45 m/s
P > 20 barg 60 m/s
LINE SIZING CRITERIA FOR TWO PHASE FLOWS
For two-phase flows the average density will be calculated and the lines will be sized according to the following criteria:
* Average velocity: 10 to 23 m/s
* ρ (average) x V² (average): 5 000 to 15 000 kg/m/s²
Flow characteristic shall be evaluated, and slug flow shall be avoided when feasible.
For steam condensate at saturation point (i.e. not subcooled), lines are to be sized for maximum vapor flashing duty and
increased by one line size to avoid high velocity slugs of water.
