PIPING FLEXIBILITY AND STRESS DESIGN SPECIFICATION
ANALYSIS CRITERIA
Brown & Root
International
Q-CHEM PETROCHEMICAL COMPLEX P55-1D-7979
MESAIEED INDUSTRIAL CITY, STATE OF QATAR
REV: 0 ENGINEERING SERVICES BY BROWN & ROOT INTERNATIONAL, Inc./ TECHNIP PAGE 1 OF 7
Revision No. 0 1 2 3 4 5 6
Date 03DEC99
By JB
Checked By JJP
Approved By HJR
PIPING FLEXIBILITY AND STRESS DESIGN SPECIFICATION
ANALYSIS CRITERIA
Brown & Root
International
Q-CHEM PETROCHEMICAL COMPLEX P55-1D-7979
MESAIEED INDUSTRIAL CITY, STATE OF QATAR
REV: 0 ENGINEERING SERVICES BY BROWN & ROOT INTERNATIONAL, Inc./ TECHNIP PAGE 2 OF 7
TABLE OF CONTENTS
Section Title Page No.
1. GENERAL..................................................................................................................................... 2
1.1 Scope............................................................................................................................................ 2
1.2 Q-Chem Specifications, Brown & Root International, Inc./Technip (KBRT) Documents, Codes,
and Industry Standards................................................................................................................. 2
2. DESIGN CONDITIONS................................................................................................................. 3
2.1 Thermal Effects............................................................................................................................. 3
2.2 Friction Effects.............................................................................................................................. 3
2.3 Wind Effects.................................................................................................................................. 3
2.4 Seismic Requirements.................................................................................................................. 3
2.5 Snow and Ice Loads...................................................................................................................... 3
2.6 Safety Valves................................................................................................................................ 3
3. ALLOWABLE LOADS.................................................................................................................. 3
3.1 Vessels and Shell and Tube Heat Exchangers.............................................................................3
3.2 Machinery...................................................................................................................................... 4
3.3 Air Fin Coolers.............................................................................................................................. 4
3.4 Fired Heaters................................................................................................................................ 4
3.5 Battery Limit "Anchors".................................................................................................................. 4
4. FLEXIBILITY................................................................................................................................. 4
5. PIPING FLEXIBILITY ANALYSIS CRITERIA...............................................................................5
5.1 General......................................................................................................................................... 5
5.2 Mandatory Computer Analysis...................................................................................................... 5
5.3 Mandatory Investigation................................................................................................................ 6
1. GENERAL
1.1 Scope
1.1.1 The purpose of this document is to provide basic piping stress analysis design data requirements and the
requirements for documentation of the piping stress analyses.
1.1.2 All piping systems shall be evaluated for adequate flexibility and stress level in accordance with the
applicable codes and standards referenced herein.
1.2 Q-Chem Specifications, Brown & Root International, Inc./Technip (KBRT) Documents, Codes, and
Industry Standards
Documents, Codes, and Industry Standards referred to herein, or in the commodity code description, form a
part of the requirements of this Specification in the manner and to the extent specified. Unless otherwise
specified, the date of edition or revision of the referenced Codes or Industry Standards shall be as specified in
Appendix E of ASME B31.3.
Q-CHEM SPECIFICATIONS
9.7, "Units of Measurement and Language" (Exhibit A)
BROWN & ROOT INTERNATIONAL, INC./TECHNIP (KBRT)
QCC-A4-00-EM-008, "Project Design Data"
QCC-A4-00-S-1001, "Structural Design Criteria"
AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)
ASME B31.1, "Power Piping"
ASME B31.3-96, "Process Piping" including Addenda through B31.3b-97
AMERICAN PETROLEUM INSTITUTE (API)
API 610, "Centrifugal Pumps for Petroleum, Heavy Duty Chemical, and Gas Industry Services"
API 611, "General-Purpose Steam Turbines for Refinery Service"
API 612, "Special-Purpose Steam Turbines for Refinery Services"
API 617, "Centrifugal Compressors for General Refinery Service"
PIPING FLEXIBILITY AND STRESS DESIGN SPECIFICATION
ANALYSIS CRITERIA
Brown & Root
International
Q-CHEM PETROCHEMICAL COMPLEX P55-1D-7979
MESAIEED INDUSTRIAL CITY, STATE OF QATAR
REV: 0 ENGINEERING SERVICES BY BROWN & ROOT INTERNATIONAL, Inc./ TECHNIP PAGE 3 OF 7
API 618, "Reciprocating Compressors for General Refinery Service"
API 661, "Air-Cooled Heat Exchangers for General Refinery Services"
API 676, "Positive Displacement Pumps - Rotary"
NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)
NEMA SM 23, "Steam Turbines for Mechanical Drive Service"
2. DESIGN CONDITIONS
2.1 Thermal Effects
2.1.1 The maximum and minimum ambient temperature to be considered for thermal calculations are defined
in Project Design Data.
2.1.2 In long pipeways, the effect of solar heating on uninsulated lines normally operating close to ambient
temperature shall be considered.
2.2 Friction Effects
The effect of friction shall be calculated based on the following:
Surfaces Friction Factor
Steel to steel 0.3
Stainless steel to PTFE 0.1
PTFE to PTFE 0.1
2.3 Wind Effects
The design of piping systems subjected to wind effects shall be in accordance with Project Specification
QCC-A4-00-S-1001.
2.4 Seismic Requirements
Seismic design requirements on piping systems shall be in accordance with Project Specification
QCC-A4-00-S-1001.
2.5 Snow and Ice Loads
No analysis for snow loads shall be undertaken. For uninsulated cold lines where ice formation is anticipated,
the additional sustain load due to ice shall be accounted for in the pipe support design and stress evaluation.
2.6 Safety Valves
Forces and moments due to relief valve discharge in open systems shall be calculated in accordance with
ASME B31.1 Appendix II.
3. ALLOWABLE LOADS
3.1 Vessels and Shell and Tube Heat Exchangers
For all nozzles of ASME Section VIII, Division 2 Vessels, piping engineers must provide piping nozzle loads to
the Vessel Mechanical group, to be included into their mechanical design.
Thermal loads are to be calculated with design temperature.
In the case of ASME Section VIII, Division 1 Vessels, for all lines analyzed, which are NPS 30 and larger, piping
nozzle loads must be transmitted to the Vessel Mechanical group to be included into their mechanical design.
Same for Exchangers.
PIPING FLEXIBILITY AND STRESS DESIGN SPECIFICATION
ANALYSIS CRITERIA
Brown & Root
International
Q-CHEM PETROCHEMICAL COMPLEX P55-1D-7979
MESAIEED INDUSTRIAL CITY, STATE OF QATAR
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In the case of ASME Section VIII, Division 1 Vessels, for all lines analyzed, which are NPS 28 and smaller,
piping nozzle loads have to be transmitted to the Vessel Mechanical group to be included into their mechanical
design, only when the thermal stress exceeds 703. Kgf/cm2 (10 000 psi). This criteria also assume that most of
weight loads will be taken away from the nozzle through pipe supports and that the lines are properly guided.
Similar for Exchangers.
3.2 Machinery
Forces and moments for rotating and reciprocating equipment shall comply with the requirements of the
applicable standard listed below. Loads not in compliance with, or outside the scope of these standards shall
be qualified by agreement with the equipment supplier.
API 610, "Centrifugal Pumps for Petroleum, Heavy Duty Chemical, and Gas Industry Services"
API 611, "General-Purpose Steam Turbines for Refinery Service"
API 612, "Special-Purpose Steam Turbines for Refinery Services"
API 617, "Centrifugal Compressors for General Refinery Service"
API 618, "Reciprocating Compressors for General Refinery Service"
API 676, "Positive Displacement Pumps - Rotary"
NEMA SM23, "Steam Turbines for Mechanical Drive Service"
3.3 Air Fin Coolers
Forces and moments on Air Fin Cooler nozzles shall be in accordance with API 661. Loads not in compliance
with these allowables shall be qualified by agreement with the equipment supplier.
3.4 Fired Heaters
Loads on heater nozzles shall be as specified or approved by the Supplier.
3.5 Battery Limit "Anchors"
3.5.1 In general, all lines shall be "anchored" at the battery limits. If this design is not considered practical in a
special case, because a valid reason, the situation shall be brought to the attention of the Piping Mechanical
Work Group Leader in HOC for resolution. "Anchored" for this purpose shall mean restrained from movements
by axial stops and lateral guides.
3.5.2 When the battery limit is between a unit and offsites, pipe anchor will be located in the unit at the nearest
support to the battery limit. For example: Pipe anchors for the ethylene unit will be located in the ethylene unit
close to the battery limit. Exact location of anchor steel will be defined at a later date. The operating center
designing the offsites will transmit on time, the loads to its counterpart, only when the loads from his side
exceeds the following:
- 1700 N load acting in the transverse direction applied at each pipe support level.
- 3400 N load acting in the longitudinal direction applied at the center of each pipe support level.
Also, any individual load greater than 1150 N with its location must be communicated too.
4. FLEXIBILITY
4.1 Piping systems shall be designed in accordance with the requirements of ASME B31.3, and ASME 31.1, if
applicable.
4.2 Piping systems shall be analyzed for expansion, contraction, differential settlement, thermal bowing/shock,
relief valve reactions, and for the effects due to weight, wind, or earthquake, and other mechanical loadings
based on applicable piping codes and Project Specifications.
4.3 The design of piping systems for temperature shall take into account the worst thermal condition expected
during operation.
PIPING FLEXIBILITY AND STRESS DESIGN SPECIFICATION
ANALYSIS CRITERIA
Brown & Root
International
Q-CHEM PETROCHEMICAL COMPLEX P55-1D-7979
MESAIEED INDUSTRIAL CITY, STATE OF QATAR
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4.4 Piping flexibility shall be provided by change of direction in the piping using bends, loops, or offsets.
4.5 Where flexibility cannot readily be provided in accordance with 4.4, expansion joints may be considered.
Expansion joints shall be used when space or pressure drop limitation do not permit pipe bends.
4.6 Forces and moments due to weight, thermal loads and other loads imposed on equipment nozzles shall not
exceed the allowable loads for the equipment as defined in Section 3.
4.7 Directional anchors and guides shall be used to protect terminal equipment or to direct expansion into the
bends, expansion loops, and expansion joints.
4.8 Pipe guides shall be used to limit excessive wind or earthquake displacement that may cause excessive
stresses within the piping system, and to prevent buckling of long piping runs.
5. PIPING FLEXIBILITY ANALYSIS CRITERIA
5.1 General
The general criteria for the method of piping flexibility analysis is shown in Figure 1. The temperature on the
chart refers to design or flex temperature, whichever is higher, for hot lines and whichever is lower for cold
lines.
5.2 Mandatory Computer Analysis
In addition of what is indicated in accordance with Figure 1, computer flexibility analysis is mandatory for the
following. Lines analyzed will be tracked via the stress analysis line status in IPMS.
a. Piping above NPS 3 connected to Rotating equipment such as pumps (excluding in-line pumps), blowers
and compressors, and normally operates at 121ºC or higher. The piping for smaller diameters will be
provided with enough flexibility and it may be computerized only if absolutely necessary (i.e. nozzle size
more than one size smaller than the pipe).
b. Piping NPS 3 and larger connected to Gas/Steam Turbines, or Centrifugal Compressors, and normally
operates at 121ºC or higher. The piping for smaller diameters will be provided with enough flexibility and it
may be computerized only if absolutely necessary (i.e. nozzle size more than one size smaller than the
pipe).
c. Piping NPS 3 and larger connected to Reciprocating pumps and compressors, whose normal operating
temperature exceeds 121ºC or higher. The inclusion in the analysis or not, of NPS 2 and smaller sizes will
be evaluated on a case by case basis.
d. Lines NPS 3 and larger connected to air-fin coolers.
e. All process lines connected to pressure vessels designed in accordance with ASME Section VIII,
Division 2.
f. In general, all aluminum piping, lines with aluminum flanges, and all lines connected to aluminum
equipment (e.g., core exchangers) will be analyzed. However, some lines may be excluded if good
engineering judgement justifies such action (i.e. near ambient temperature, with Expansion Joints, or so).
Note: Calculations shall be done in metric system as defined in Specification 9.7. (Exhibit A).
PIPING FLEXIBILITY AND STRESS DESIGN SPECIFICATION
ANALYSIS CRITERIA
Brown & Root
International
Q-CHEM PETROCHEMICAL COMPLEX P55-1D-7979
MESAIEED INDUSTRIAL CITY, STATE OF QATAR
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5.3 Mandatory Investigation
In addition to what is indicated per Figure 1, the following lines require mandatory investigation:
Note: Mandatory investigation means: Visual inspection, or Hand calculation or Computer analysis to be
defined on case by case basis. A formal computer analysis may not be performed if the piping
systems are duplicates, or very similar to another piping system already calculated with similar or more
severe design conditions.
a. Lines having substantial concentrated loads such as valves or unsupported vertical risers/branches.
b. Lines having local reduction in strength due to installation of special fittings (if reducer, greater than one (1)
size reduction).
c. Lines NPS 3 and larger connected to plate and frame heat exchangers.
d. All piping subject to high cyclic temperatures.
e. All double containment lines, jacketed piping, and glass lined piping.
f. Blowdown headers and flare headers.
g. Lines with slug flow or two-phase flow.
h. Relief valve and rupture disc piping.
i. Unbalanced piping configurations such as a long piping run with a short anchored branch.
j. Critical process lines
k. Underground process lines with a Design temperature greater than 38ºC or less than 4ºC.
l. Piping with short term temperature variations such as steamout.
PIPING FLEXIBILITY AND STRESS DESIGN SPECIFICATION
ANALYSIS CRITERIA
Brown & Root
International
Q-CHEM PETROCHEMICAL COMPLEX P55-1D-7979
MESAIEED INDUSTRIAL CITY, STATE OF QATAR
REV: 0 ENGINEERING SERVICES BY BROWN & ROOT INTERNATIONAL, Inc./ TECHNIP PAGE 7 OF 7
DETAIL 1
FOR CARBON STEEL OR LOW CHROME PIPE
DETAIL 2
FOR STAINLESS STEEL PIPE
FIGURE 1
GENERAL CRITERIA FOR FLEXIBILITY ANALYSIS
NOTES:
1. Lines in this category can be analyzed by visual or approximate methods.
2. Lines in this category require formal analysis. This analysis can be done by approximate or
comprehensive methods. Documentation is required.
3. Line analysis in this category require a comprehensive (typically computer) analysis. Other methods may
be used with owners approval. Documentation is required.
