Technical Specification for Design of Steam Piping Systems

1. SCOPE
……………………………………………..
2. REFERENCE DOCUMENTS
3. DEFINITIONS
4. GENERAL REQUIREMENTS ………………5. BOOTLEGS AND TRAPS
6. TIE-IN TO EXISTING STEAM SYSTEMS

1.Scope
This specification covers the general requirements to be used in the layout of piping arrangements in
steam services.
2.Reference Documents
SABIC Engineering Standards (SES)
P04-S01 Piping Material Standard Specifications- Part 3- Utilities Services
P01-E19 Utility Piping System – Connection to Process Equipment, Safety Showers, and Eyewash
Stations
P01-E20 Industrial Insulation
3. Definitions
4. General Requirements
4.1 Steam piping shall be routed on the utility level of the pipe rack. Steam headers in the rack shall be
located near the column with the hottest line to the outside with cooler steam and condensate lines inside
of that. This is to maximize the available length of expansion loops.
4.2 All steam lines larger than 2 ½” shall be on shoes to prevent damage to the insulation.
4.3 If the design temperature is above 315°C, do not insulate the pipe flanges if the material spec calls for
standard bolts. Above this temperature the bolts can stretch or back out. Confirm with Material Engineer
which type of bolt is specified.
4.4 Make all branch connections on top of the steam headers.
4.5 Relief valve tail pipes in steam service that are routed to atmosphere shall have drip rings near the
bottom of the vertical run to collect hot condensate running down the outside of the pipe. The drip ring
shall have a drain line to grade to prevent hot condensate from falling on personnel and equipment. A ½
inch weep hole shall be made in the bottom of the elbow immediately downstream of the relief valve to
drain off any condensate that would collect inside of the tail pipe. This weep hole shall be piped to grade.
5. Bootlegs and Traps
5.1 Steam lines shall be provided with bootlegs and steam traps before any riser, at dead ends or on
excessively long runs of piping (See SES P01-E19) for sufficient condensate removal and to ensure dry
quality steam at destination.
5.2 Bootlegs and traps shall be located immediately up stream of all control valves and steam turbine
inlets, and downstream of all steam turbine outlet valves (unless the exhaust header from a turbine slopes
to the section header without a pocket).
5.3 Steam traps shall be located below and as close as possible to the equipment or line being drained.
Traps shall be accessible from grade or platform. Check with Material Engineer whether trap may be
installed in the vertical or must be horizontal position.
6. Tie-in to Existing Steam Systems
If the new steam line ties into an existing steam system, the following items must be verified.
a. Confirm that the existing steam system has flanges and valves with the correct flange rating to be
compatible to the new steam system.
b. Confirm that the existing steam system still has the necessary wall thickness for the design pressure of
the new system. Verify with plant ultrasonic testing records or request that new tests be performed.