ASTM F722-18(2022)

Standard Specification for Welded Joints for Shipboard Piping Systems

ABSTRACT
This specification covers typical details of welded joints commonly used in shipboard piping systems. These joints and other joints may be used provided the welding procedures used have been qualified in accordance with the applicable regulatory rules and regulations. The maximum butt weld reinforcement of differnet nominal wall thicknesses of pipe or tube shall be discussed.
SCOPE
1.1 This specification covers typical details of welded joints commonly used in shipboard piping systems. These joints and other joints may be used provided the welding procedures used have been qualified in accordance with the applicable regulatory rules and regulations.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 25.160.40 - Welded joints and welds
• Technical Committee: F25 - Ships and Marine Technology
• Drafting Committee: F25.11 - Machinery and Piping Systems

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F722 −18 (Reapproved 2022) An American National Standard
Standard Specification for
Welded Joints for Shipboard Piping Systems
ThisstandardisissuedunderthefixeddesignationF722;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 Butt-Welded Joints for Pipes, Valves, Fittings, and
Flanges:
1.1 This specification covers typical details of welded joints
Fig. 1 Butt Joint, Square
commonly used in shipboard piping systems. These joints and
Fig. 2 Butt Joint, V-Grooved
other joints may be used provided the welding procedures used
Fig. 3 Butt Joint, V-Grooved, Welded Both Sides
have been qualified in accordance with the applicable regula-
Fig. 4 Butt Joint, Double V-Grooved, Welded Both Sides
tory rules and regulations.
Fig. 5 Butt Joint, Compound Bevel V-Grooved, Welded
1.2 The values stated in inch-pound units are to be regarded
Both Sides
as standard. The values given in parentheses are mathematical
Fig. 6 Butt Joint, V-Grooved, Miter Type
conversions to SI units that are provided for information only
Fig. 7 Butt Joint, V-Grooved, Welded with Bevel End-
and are not considered standard.
Type Backing Ring
1.3 This international standard was developed in accor-
Fig. 8 Butt Joint, Compound Bevel V-Grooved, Welded
dance with internationally recognized principles on standard-
with Bevel End-Type Backing Ring
ization established in the Decision on Principles for the
Fig. 9 Butt Joint, V-Grooved Welded with Bevel End
Development of International Standards, Guides and Recom-
Lug-Type Backing Ring
mendations issued by the World Trade Organization Technical
Fig. 10 Butt Joint, V-Grooved, Welded with Square End-
Barriers to Trade (TBT) Committee.
Type Backing Ring
2. Referenced Documents
Fig. 11 Butt Joint, V-Grooved, Welded with Consumable
Insert Ring
2.1 ASME Standards:
Fig. 12 Butt Joint, Compound Bevel V-Grooved, Welded
B31.1 Power Piping
with Consumable Insert Ring
2.2 Federal Standards:
Code of Federal Regulations Title 46 Fig. 13 Butt Joint, U-Grooved, Welded with Consumable
Shipping, Parts 41 to 69 Insert Ring
Fig. 14 Butt Joint, V-Grooved, Welded with Consumable
3. Application, Service, Limitations, and List of Weld
Insert Ring
Joint Details
Fig. 15 Butt Joint, Socket Weld to Socket Weld Valve,
3.1 Details of welded joints, including application, service,
Fitting or Flange Welded on Pipe Nipple
and limitation notes, are provided in the appropriate figures, as
Fig. 16 Butt Joint, Transition Between Unequal Inside and
follows:
Outside Diameter Components
3.1.2 Fillet Welded Joints for Valves, Fittings, and Flanges:
This specification is under the jurisdiction of ASTM Committee F25 on Ships
Fig. 17 Fillet Welded Sleeve-Type Pipe Coupling
and Marine Technology and is the direct responsibility of Subcommittee F25.11 on
Fig. 18 Fillet Welded Socket Weld Fitting or Valve
Machinery and Piping Systems.
Current edition approved Oct. 1, 2022. Published October 2022. Originally
Fig. 19 Fillet Welded Socket Weld-Flange
approved in 1981. Last previous edition approved in 2018 as F722 – 18. DOI:
Fig. 20 Double Fillet Welded Slip-On Flange (Forged)
10.1520/F0722-18R22.
Fig. 21 Double Fillet Welded Slip-On Flange (Plate Type)
Available from American Society of Mechanical Engineers (ASME), ASME
International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
Fig. 22 Fillet Welded Slip-On Flange (Plate Type), Single
www.asme.org.
Bevel
Available from U.S. Government Printing Office, Superintendent of
Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F722−18 (2022)
3.1.3 Fabricated Joints: Fig. 32 Fillet Reinforced External Root Connection,
Fig. 23 Fillet Welded Internal Root Connection Single Bevel with Integrally Reinforced Outlet
Fig. 24 Fillet Welded External Root Connection Fig. 33 Fillet Reinforced External Root Connection
Fig. 25 Fillet Reinforced External Root Connection Single Welded Both Sides, Single Bevel with Integrally Reinforced
Bevel Outlet
Fig. 26 Fillet Reinforced External Root Connection,
Single Bevel, Welded Both Sides 4. Piping Classifications and Butt Weld Reinforcements
Fig. 27 Fillet Reinforced External Root Connection,
4.1 Piping classifications in accordance with Subpart 56.04
Single Bevel, Welded with Square End Backing Ring
of USCG Regulations apply to this specification.
Fig. 28 Fillet Reinforced Internal Root Connection, Single
4.2 Maximum thickness of butt weld reinforcements in
Bevel, Welded with Square End Backing Ring
accordance with 46 CFR Subpart 56.70, Table 56.70-15, of
3.1.4 Outlet and Boss Connections:
USCG Regulations are listed in Table 1.
Fig. 29 Fillet Reinforced Boss Connection Without Pilot,
Single Bevel
5. Keywords
Fig. 30 Fillet Reinforced Boss Connection with Pilot,
Single Bevel 5.1 backing ring pipe welds; boss connections; flange
Fig. 31 Fillet Reinforced Boss Connection (Couplet) with welds; miter joint weld; pipe welds; root connections; sleeve
Integral Backing Ring pipe welds; socket welds; welded joints
F722−18 (2022)
⁄16 in. = 2 mm
⁄8 in. = 3 mm
⁄8 in. = 3 mm
⁄16 in. = 5 mm
⁄8 in. = 22 mm
Application—Class II piping.
Application—Class I and II piping above 2-in. NPS.
Systems or Service—For services such as gravity drains (including plumbing),
System or Service—All.
vents, and overflows.
Remarks—1. Internal weld shall be made first and ground, chipped, or cleaned
Remarks—1. Root of weld need not be ground.
by some other means to assure sound welds.
FIG. 1 Butt Joint, Square
2. The “L” dimension should be held to a minimum to facilitate welding and
inspection on the inside surface of the pipe.
FIG. 3 Butt, Joint, V-Grooved, Welded Both Sides
⁄16 in. = 2 mm
⁄16 in. = 2 mm
1 ⁄8 in. = 3 mm
⁄8 in. = 3 mm
⁄8 in. = 22 mm
⁄8 in. = 22 mm
Application—Class I and II piping above 2-in. NPS.
Application—Class II piping.
System or Service—All.
System or Service—All provided root of weld is visually inspected where
Remarks—1. Internal weld shall be made first and ground, chipped, or cleaned
possible to ensure complete weld penetration.
by some other means to assure sound welds.
Remarks—1. For services such as vents, overflows, and gravity drains (includ-
2. The “L” dimension should be held to a minimum to facilitate welding and
ing plumbing) the root of the weld need not be ground.
inspection on the inside surface of the pipe.
FIG. 2 Butt Joint, V-Grooved
FIG. 4 Butt Joint, Double V-Grooved, Welded Both Sides
F722−18 (2022)
1 1 3 7
in. ⁄16 ⁄8 ⁄16 ⁄8
mm 2 3 5 22
1 1 3 7
in. ⁄16 ⁄8 ⁄4 ⁄8
Application—Class I and II piping.
mm 2 3 19 22
System or Service—All, except as noted in remarks.
Remarks—1. Backing ring may be tack-welded in place to facilitate fabrication.
Application—Class I and II piping above 2-in. NPS.
2. When used in the following services, backing rings shall be removed.
Systems or Service—All.
(A) Lube oil service discharge piping from the lube oil pumps to the reduction
Remarks—1. Internal weld shall be made first and ground, chipped, or cleaned
gears, HP and LP turbines, and lube oil gravity tank.
by some other means to assure sound welds.
(B) Superheated steam outlet piping from the main boilers to the HP and LP
2. The “L” dimension should be held to a minimum to facilitate welding and
turbines and turbo generators and desuperheated steam from the main boilers to
inspection on the inside surface of the pipe.
turbine driven main feed pumps.
(C) Central hydraulic systems.
FIG. 5 Butt Joint, Compound Bevel V-Grooved, Welded Both
FIG. 7 Butt Joint, V-Grooved, Welded with Bevel End-Type
Sides
Backing Ring
1 1 1 3 3 7
⁄16 in. = 2 mm
in. ⁄16 ⁄8 ⁄4 ⁄8 ⁄4 ⁄8
⁄8 in. = 3 mm
mm 2 3 6 10 19 22
⁄8 in. = 22 mm
Application—Class I and II piping.
Application—Class II piping where use will not cause objectionable pressure
System or Service—All, except as noted in remarks.
drop or turbulence.
Remarks—1. Backing ring may be tack-welded in place to facilitate fabrication.
System or Service—All provided root of weld is visually inspected where
2. When used in the following services, backing rings shall be removed.
possible to ensure complete weld penetration.
(A) Lube oil service discharge piping from the lube oil pumps to the reduction
Remarks—1. For services such as vents, overflows, and gravity drains (includ-
gears, HP and LP turbines, and lube oil gravity tank.
ing plumbing), the root of the weld need not be ground.
(B) Superheated steam outlet piping from the main boilers to the HP and LP
2. Miter segments shall be designed in accordance with ASME B31.1, para-
turbines and turbo generators and desuperheated steam from the main boilers to
graph 104.3.3, and 46 CFR 56.07-10(f).
turbine driven main feed pumps.
FIG. 6 Butt Joint, V-Grooved, Miter Type (C) Central hydraulic systems.
FIG. 8 Butt Joint, Compound Bevel V-Grooved, Welded with
Bevel End-Type Backing Ring
F722−18 (2022)
1 1 1 3 7
in. ⁄64 ⁄32 ⁄16 ⁄4 ⁄8
⁄8 in. = 22 mm
mm 0.4 1 2 19 22
Application—Class I and II piping.
Application—Class I and II piping.
Systems or Service—All, except as noted in remarks.
System or Service—All.
Remarks—1. Backing ring may be tack-welded in place to facilitate fabrication. 1
Remarks—1. Internal misalignment of pipes shall not exceed ⁄16 in. (2 mm).
2. When used in the following services, backing rings shall be removed.
2. Consumable insert ring shall be centered before welding.
(A) Lube oil service discharge piping from the lube oil pumps to the reduction
FIG. 12 Butt Joint, Compound Bevel V-Grooved, Welded with
gears, HP and LP turbines, and lube oil gravity tank.
Consumable Insert Ring
(B) Superheated steam outlet piping from the main boilers to the HP and LP
turbines and turbo generators and desuperheated steam from the main boilers to
turbine driven main feed pumps.
(C) Central hydraulic systems.
FIG. 9 Butt Joint, V-Grooved Welded with Bevel End Lug-Type
Backing Ring
1 1 1 3
in. ⁄64 ⁄32 ⁄16 ⁄16
mm 0.4 1 2 5
Application—Class I and II Piping.
System or Service—All.
1 1 3 7
Remarks—1. Internal misalignment of pipes shall not exceed ⁄16 in. (2 mm).
in. ⁄16 ⁄8 ⁄16 ⁄8
2. Consumable insert ring shall be centered before welding.
mm 2 3 5 22
FIG. 13 Butt Joint, U-Grooved, Welded with Consumable Insert
Application—Class I and II piping.
Ring
Systems or Service—All.
Remarks—1. After welding, backing ring shall be machined flush with inside
diameter of pipe or fitting.
FIG. 10 Butt Joint, V-Grooved, Welded with Square End-Type
Backing Ring
0.020 in. = 0.51 mm
Application—Class I and II piping.
System or Service—All.
Remarks—1. Internal misalignment of pipes shall not exceed ⁄32 in. (1 mm).
1 1 1 7
in. ⁄64 ⁄32 ⁄16 ⁄8
2. Consumable insert ring shall be centered before welding.
mm 0.4 1 2 22
FIG. 14 Butt Joint, V-Grooved, Welded with Consumable Insert
Ring
Application—Class I and II piping.
System or Service—All.
Remarks—1. Internal misalignment of pipes shall not exceed ⁄16 in. (2 mm).
2. Consumable insert ring shall be centered before welding.
FIG. 11 Butt Joint, V-Grooved, Welded with Consumable Insert
Ring
F722−18 (2022)
⁄16 in. = 2 mm
Application—Class I piping 3-in. NPS max where not subject to full radiography
by 46 CFR 56.95-10. Class II piping all sizes.
⁄16 in. = 2 mm
Systems or Service—All.
⁄4 in. = 6 mm 1
Remarks—1. Size of weld shall be 1.4 T min but not less than ⁄8 in. (3 mm).
⁄8 in. = 10 mm
2. ForClassIpiping,depthofinsertionofpipe,tube,orfittinginsleeveshallnot
be less than ⁄8 in. (10 mm).
Application—Fittings: See Fig. 18. Flanges: See Fig. 19.
3. Weld to be deposited in a minimum of two passes unless specifically
System or Service—See Fig. 18 and Fig. 19.
approved otherwise in a special procedure qualification.
Remarks—1. Size of weld shall be equal to or greater than “T.”
4. For Class I piping, the inside diameter of the sleeve shall not exceed the
2. ForClassIpiping,depthofinsertionofthepipenippleintothefittingshallnot
outside diameter of the pipe, tube, or fitting by more than 0.080 in. (2.03 mm).
be less than ⁄8 in. (10 mm).
5. Couplings may be used with flat or beveled end pipes and fitting.
3. Weld to be deposited in a minimum of two passes unless specifically
FIG. 17 Fillet Welded Sleeve-Type Pipe Coupling
approved otherwise in a special procedure qualification.
FIG. 15 Butt Joint, Socket Weld to Socket Weld Valve, Fitting or
Flange Welded on Pipe Nipple
⁄16 in. = 2 mm
Application—Class I piping 3-in. NPS max where not subject to full radiography
by 46 CFR 56.95-10. Class II piping all sizes.
System or Service—All, except socket welds shall not be used where severe
erosion or crevice corrosion is expected to occur.
1 1
Remarks—1. Size of weld shall be 1 ⁄4 T min but not less than ⁄8 in. (3 mm).
2. ForClassIpiping,depthofinsertionofpipeortubeintothefittingshallnotbe
less than ⁄8 in. (10 mm).
3. Weld to be deposited in a minimum of two passes unless specifically
approved otherwise in a special procedure qualification.
FIG. 18 Fillet Welded Socket Weld Fitting or Valve
FIG. 16 Butt Joint, Transition Between Unequal Inside and
Outside Diameter Components
F722−18 (2022)
⁄16 in. = 2 mm
Application—Class II piping not exceeding 150 psi (1034 kPa) or 450 °F
Application— Class I piping 3-in. NPS max for 600# and lower classes and
(232 °C).
2 ⁄2-in. NPS for 900 and 1500# classes. 3-in. size not permitted where subject to
System or Service—All.
full radiography by 46 CFR 56.95-10. Class II piping all sizes.
Remarks—1.SizeofWeld8aW1shallbe1.4“T”minbutmaybelimitedto ⁄32
System or Service—All, except socket welds shall not be used where severe
in. (13 mm).
erosion or crevice corrosion is expected to occur.
2. Size of Weld W2 shall be equal to “T” or ⁄4 in. (6 mm), whichever is smaller.
Remarks—1. SizeofWeldW1shallbe1.4Tmin.forClassIIpiping,sizeofweld
1 3
3. Distance X shall be T plus ⁄16 in. (2 mm) min but may be limited to ⁄8 in. (10
may be limited to ⁄32 in. (13 mm) max.
mm).
2. Weld to be deposited in a minimum of two passes unless specifically
FIG. 21 Double Fillet Welded Slip-
...