Technical Specification for Design of Water Piping Systems

1. SCOPE……………………………………2. REFERENCE DOCUMENTS
3. DEFINITIONS
4. GENERAL REQUIREMENTS ……5. POTABLE WATER

1. Scope
This specification covers the general requirements to be used in the layout of piping arrangements in
water services such as cooling water, utility water and potable water.
2. Reference Documents
SABIC Engineering Standards
P04-S01 Piping Material Standard Specifications- Part 3- Utility Service
P01-E20 Industrial Insulation
3. Definitions
4. General Requirements
4.1 Water piping shall be routed on the utility level of the pipe rack. Do not locate water piping next to hot
lines. Radiated heat from the hot line can heat the water line. Place ambient temperature lines, such as air
lines, between them to act as a buffer area.
4.2 Consider routing large diameter water lines, over 24 inches, underground to minimize the rack loads,
to maximize the available rack space for other lines and to decrease the overall width of the rack.
4.3 Branches from water headers shall be taken off the top of the header.
4.4 Cooling water lines smaller than 1 inch NPS running to equipment shall be taken from the top of the
supply line to prevent plugging.
4.5 Dead legs in cooling water lines shall be avoided.
4.6 Allow for thermal expansion of the water between two closed block valves by adding a thermal relief
valve. The tail pipe from the thermal relief valve shall be routed to grade and properly supported.
4.7 Verify necessity of load pads on large diameter water lines.
4.8 If winter weather conditions will drop below freezing, avoid dead ends and non-flowing lines in water
piping.
5. Potable Water
5.1 The maximum temperature of potable water to safety showers and eyewash stations is 37°C nor be
lower than 15°C. A water chiller may be required for specific locations to maintain the potable water
temperature supplied to safety showers and eyewash stations.
5.2 Potable water piping shall be routed underground to keep it cool. Any potable water piping routed
above ground shall be insulated as specified in SES P01-E20.
5.3 Verify that there is enough volume of proper temperature water available for a 10 to 15 minute
continuous supply to each safety shower and eyewash.