1 Scope

NOTE This standard covers the devices and fabricated piping configurations used to accommodate thermal expansion and contraction in mechanical piping systems for commercial, institutional, and industrial buildings. (1.1)

NOTE Covered devices include metallic bellows expansion joints (single unrestrained, tied, hinged, gimbal, pressure-balanced, and externally pressurized), slip/sleeve expansion joints, rubber and elastomeric expansion joints, ball-joint pairs, and fabricated expansion loops and offsets. (1.2)

NOTE Thermal movement is the controlling design action. (1.3)

NOTE Pipe grows and shrinks as its temperature changes; a long run develops force and displacement that fixed anchors and standard hangers cannot safely absorb. This standard governs the devices that take up that movement and the anchors and guides that direct it. (1.3.1)

NOTE Covered services include hydronic heating and cooling piping, steam and condensate piping, domestic hot-water recirculation, and other piped services where temperature differentials produce significant pipe growth. (1.4)

NOTE Anchors and guides are included only to the extent they are integral to the function of a thermal-movement device. (1.5)

NOTE The hanger and brace catalog itself - rod sizing, clevis types, spring hangers, riser clamps, and seismic bracing - is specified in Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current edition.sync/hangers-and-supports; this standard cites it for guide and anchor hardware but does not repeat it. (1.5.1)

NOTE This standard applies to new construction and renovation, from small commercial through large institutional and industrial facilities. (1.6)

NOTE Pipe material, pressure class, joining method, and insulation for the host system are specified in the governing piping standard, not here. (1.7)

NOTE Hydronic systems are governed by Hydronic PipingHydronic PipingResolves to the current edition.sync/hydronic-piping, steam and condensate by Steam And Condensate PipingSteam and Condensate PipingResolves to the current edition.sync/steam-and-condensate-piping, and chilled and condenser water by Chilled And Condenser Water PipingChilled and Condenser Water PipingResolves to the current edition.sync/chilled-and-condenser-water-piping. (1.7.1)

NOTE Water-hammer and hydraulic-shock arrestors are specified in Water Hammer ArrestorsWater Hammer Arresters and Shock ControlResolves to the current edition.sync/water-hammer-arrestors and are not a substitute for thermal-movement devices. (1.8)

NOTE Vibration-isolating flexible pump connectors are coordinated through Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current edition.sync/hangers-and-supports; an expansion joint is not a vibration isolator. (1.9)

NOTE Structural building expansion joints in the floor, wall, or roof envelope, and HVAC duct expansion joints on the air side, are outside the scope of this standard. (1.10)

2 Referenced Standards

2.1 Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.

2.2 Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

Standard	Title
ASME B31.1-2024	Power Piping (Mandatory Appendix P, metallic bellows expansion joints)
ASME B31.3-2024	Process Piping (Appendix X, metallic bellows fatigue)
ASME B31.9-2022	Building Services Piping
EJMA Standards, 11th Edition	Standards of the Expansion Joint Manufacturers Association
ASTM F1120-87 (2019)	Circular Metallic Bellows Type Expansion Joints for Piping Applications
ASTM F2686-14 (2020)	Rubber Expansion Joints
MSS SP-129-2019	Piping Expansion Joints - Application, Design, and Fabrication
ASME B16.5-2017	Pipe Flanges and Flanged Fittings
ASHRAE Handbook - HVAC Systems and Equipment (2020)	Piping chapter, thermal expansion accommodation

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following action submittals for review before fabrication or ordering:

Product data for each expansion device, including type, size, end-connection class, materials, rated working pressure and temperature, rated axial/lateral/angular movement, spring rate, and effective bellows area.
Manufacturer's cycle-life rating for each metallic bellows joint, with the basis (EJMA or ASTM F1120) stated.
Shop drawings showing each anchor and guide, with locations dimensioned relative to the device, anchor and guide types, and the structural attachment detail.
A piping movement diagram for each run with an expansion device, showing calculated thermal movement (ΔL), the cold-set offset, and the direction each device absorbs.
Anchor reaction loads (pressure thrust, weight, and friction) transmitted to the structure, in a form the Structural Engineer of Record can review.
Manufacturer's installation instructions, including bolt torque sequence, shipping-bar removal, and field test-pressure limits.

Action submittals requiredcheckbox

☑ Product data for each expansion device

☑ Cycle-life rating (basis stated)

☑ Anchor and guide shop drawings

☑ Piping movement diagram with cold-set offset

☑ Anchor reaction loads for structural review

☑ Manufacturer's installation instructions

3.1.2 A formal pipe flexibility and stress analysis shall be submitted for steam, high-temperature hot-water (above 250°F), and any run exceeding 200 ft without natural flexibility.

3.1.3 The stress analysis shall be performed to the governing code (ASME B31.1 or B31.3) using recognized pipe-stress software and shall be sealed by a licensed Professional Engineer.

Formal pipe-stress analysis requiredradio

○ Not required (B31.9 simplified rules apply)

● Required for steam and HTHW systems

○ Required for all expansion-device runs

3.2 Closeout Submittals

3.2.1 The Contractor shall submit the following closeout submittals before substantial completion:

Operation and maintenance data for each expansion device, including inspection intervals and packing-replacement procedure for slip joints.
Record drawings showing as-built anchor and guide locations and the as-installed cold-set position of each device.
Manufacturer's warranty documentation.
Field test reports for the piping in which each device is installed.

Closeout submittals requiredcheckbox

☑ O&M data for each device

☑ Record drawings (anchors, guides, cold-set)

☑ Warranty documentation

☑ Field test reports

3.3 Informational Submittals

3.3.1 The Contractor shall submit the following informational submittals:

Factory hydrostatic test certificates for each metallic bellows and rubber expansion joint.
Material test reports or mill certificates for bellows and end-connection materials where required by the governing code.
Welder qualification records for any field-fabricated loops or butt-welded joints.

Informational submittals requiredcheckbox

☑ Factory hydrostatic test certificates

☐ Material test reports / mill certs

☑ Welder qualification records

4 Quality Assurance

4.1 Metallic bellows expansion joints shall be designed and manufactured in accordance with the EJMA Standards, 11th Edition, and the governing ASME B31 code.

NOTE ASME B31.1 Mandatory Appendix P shall govern metallic bellows joints in power-piping, steam, and high-temperature hot-water service. (4.2)

NOTE Appendix P, new in the 2024 edition, consolidates the design, fatigue, and pressure-thrust requirements that previously had to be assembled from EJMA and the base code; calling it out removes ambiguity about which rules apply to bellows joints in code-governed service. (4.2.1)

4.3 Rubber and elastomeric expansion joints shall comply with ASTM F2686.

4.4 Application, anchor and guide arrangement, and field installation shall comply with MSS SP-129.

4.5 The manufacturer of metallic bellows joints shall have a minimum of five years of production experience with bellows of the specified type and size range.

NOTE A formal flexibility analysis is the default expectation for code-governed and long runs, and the simplified route is reserved for genuinely low-energy HVAC piping. (4.6)

NOTE ASME B31.9 simplified rules are acceptable for low-temperature, low-pressure building HVAC loops; ASME B31.1 or B31.3 formal analysis is required for steam, HTHW, large-diameter, or geometrically complex runs. Choosing the simplified route on a system that does not qualify is a common and consequential error. (4.6.1)

5 Environmental and Service Conditions

5.1 Each expansion device shall be selected for the maximum and minimum metal temperatures and the design pressure of the service in which it is installed.

System serviceselect

Chilled water

Condenser water

Hydronic hot water

High-temperature hot water (HTHW)

Low-pressure steam

Condensate return

Domestic hot-water recirculation

Design pressurerange

psig

50300

Default: 150 psig

5.2 Thermal movement shall be calculated for each pipe run segment as ΔL = α × L × ΔT, where α is the material thermal expansion coefficient, L is the anchored length, and ΔT is the temperature change from installation to operating condition.

Pipe material (sets thermal coefficient)select

Carbon steel

Stainless steel

Copper

CPVC

Calculated thermal movement per run (ΔL)range

in

0.2512

Default: 1 in

NOTE The thermal expansion coefficient varies by pipe material and is the single largest driver of calculated movement. (5.3)

NOTE Carbon steel grows about 0.78 in per 100 ft per 100°F (α ≈ 6.5 × 10⁻⁶ in/in·°F); stainless steel α ≈ 9.6 × 10⁻⁶ and copper α ≈ 9.5 × 10⁻⁶ in/in·°F move roughly half again as much; CPVC at α ≈ 34 × 10⁻⁶ moves several times more and almost always needs deliberate expansion provisions. (5.3.1)

5.4 The temperature difference used in sizing shall be the full range the pipe experiences, from the coldest installation or shutdown condition to the maximum operating temperature.

Maximum operating temperaturerange

°F

60400

Default: 200 °F

NOTE Typical HVAC ranges are chilled water 40-60°F (ΔT vs. ambient ≈ 30-50°F), hydronic hot water 120-200°F (ΔT ≈ 100-170°F), high-temperature hot water 250-400°F (ΔT ≈ 150-350°F), and low-pressure steam ≈ 215-250°F. (5.4.1)

6 Device Selection

6.1 The expansion-device type shall be selected on the basis of available space, pipe size, pressure, temperature, and the structural capacity available for anchors.

NOTE Fabricated loops and offsets are the preferred solution wherever space permits because they have no wear parts and require no maintenance. (6.2)

NOTE A field- or shop-fabricated loop is the same material and pressure class as the run it serves, has nothing to wear out or repack, and never voids a warranty by being installed wrong; it is preferred over any manufactured joint wherever ceiling, shaft, or chase space allows the loop legs to fit. (6.2.1)

NOTE The rubber sphere joint is the default for typical hydronic HVAC below 200°F. (6.3)

NOTE More than two-thirds of commercial HVAC hydronic work uses a single-sphere EPDM rubber joint rated 150 psig and 200°F with Class 150 flanged ends; it is compact, absorbs axial, lateral, and angular movement, and doubles as a mild vibration buffer. It is the default specified here and the starting point unless temperature, pressure, or movement rules it out. (6.3.1)

NOTE Metallic bellows joints dominate steam and high-temperature hot-water service. (6.4)

NOTE Above 200°F, elastomers degrade rapidly; stainless bellows are the rated solution for steam and HTHW and for any service where an elastomer is not listed for the temperature or fluid. (6.4.1)

6.5 Elastomeric expansion joints shall not be used on steam or on any service exceeding the elastomer's rated temperature.

6.6 The expansion device type shall be selected as scheduled.

Expansion device typeradio

○ Fabricated U-loop

○ Fabricated L-offset or Z-offset

● Rubber sphere expansion joint

○ Rubber spool expansion joint

○ Single unrestrained metallic bellows joint

○ Tied metallic bellows joint

○ Hinged or gimbal metallic bellows pair

○ Pressure-balanced metallic bellows joint

○ Externally pressurized metallic bellows joint

○ Slip/sleeve expansion joint

○ Ball-joint pair

6.7 End-Connection and Pressure Class

6.8 The end-connection type and pressure class shall match the adjacent piping connection standard and the system pressure class.

NOTE A mismatched flange class makes the joint the weak link in the system. (6.9)

6.9.1 Expansion joints are frequently ordered Class 150 flanged out of habit while the adjacent system is Class 300; the joint then becomes the lowest-rated component in the run. The end-connection class shall be verified against the system class, not assumed.

6.9.2 Flanged connections shall conform to ASME B16.5 for the specified pressure class.

End-connection typeradio

● Flanged

○ Grooved / coupled

○ Threaded

○ Butt-weld

Flange pressure classradio

● Class 150

○ Class 300

7 Metallic Bellows Expansion Joints

7.1 Metallic bellows joints shall be furnished as the sub-type required by the piping geometry and the structural anchor capacity, and the sub-type shall be scheduled.

Bellows joint sub-typeradio

● Single unrestrained (axial)

○ Tied (lateral / angular)

○ Hinged (single-plane angular)

○ Gimbal (multi-plane angular)

○ Pressure-balanced

○ Externally pressurized

NOTE The bellows sub-type determines what movement the joint absorbs and whether it imposes pressure thrust on the anchors. (7.2)

NOTE A single unrestrained joint absorbs axial movement only and transmits full pressure thrust to main anchors; a tied joint absorbs lateral and angular movement while its tie rods carry the thrust internally; hinged joints take angular movement in one plane and gimbal joints in multiple planes, used in pairs to cancel thrust; a pressure-balanced joint carries no net thrust to the anchors at all. (7.2.1)

7.3 A single unrestrained joint shall be installed only between main anchors sized for the full pressure thrust.

7.4 Pressure thrust on an unrestrained joint shall be calculated as F = P × A_eff, where P is the design pressure and A_eff is the effective bellows area from the manufacturer's EJMA data.

7.5 Tied, hinged, gimbal, and pressure-balanced joints shall be used where the structure cannot accept the pressure-thrust reaction of an unrestrained joint.

NOTE Pressure-balanced joints are the appropriate choice on rooftops, suspended piping, and at equipment nozzles where no anchor structure can take the thrust load. (7.5.1)

7.6 Externally pressurized joints should be considered for large-diameter or high-pressure axial movement because the bellows convolutions are inherently resistant to squirm.

7.7 Bellows shall be austenitic stainless steel.

Bellows materialselect

304 stainless steel

316 stainless steel

Nickel alloy (UNS N06625)

NOTE Single-ply 304 stainless steel is the default for building steam and HTHW service; 316 stainless or nickel alloy is required where the fluid or process environment demands higher corrosion resistance. (7.7.1)

7.8 The factory cycle-life rating shall meet or exceed the specified minimum for the service.

NOTE Building HVAC systems see a modest but real number of thermal cycles over their life, and the cycle rating must cover them with margin. (7.9)

NOTE A typical building system experiences 1,000-5,000 thermal cycles over a 30-year life; a 3,000-cycle minimum suits daily-cycling systems, while condensate and domestic hot-water systems that cycle frequently warrant 10,000 cycles. Under-rating the bellows for cycle count is a slow-failure mode that does not show up at startup. (7.9.1)

7.9.2 The number of bellows plies shall be specified for each metallic expansion joint based on the thermal cycling demands of the service.

Number of pliesradio

● Single-ply

○ Multi-ply

7.9.3 The rated axial movement of each metallic bellows expansion joint shall be specified based on the piping thermal movement it must accommodate.

Rated axial movementrange

in

0.512

Default: 2 in

Minimum cycle liferadio

● 3,000 cycles

○ 5,000 cycles

○ 10,000 cycles

8 Rubber and Elastomeric Expansion Joints

8.1 Rubber expansion joints shall comply with ASTM F2686 and shall be furnished as the single-sphere, multi-sphere, or spool configuration required for the movement.

Rubber joint configurationradio

● Single-sphere

○ Multi-sphere

○ Spool (straight body)

NOTE The sphere type is compact and the spool type accommodates larger axial movement. (8.2)

NOTE A single-sphere joint is the most compact and is the standard choice for hydronic HVAC; a spool (straight-body) joint accommodates greater axial movement where the run requires it. (8.2.1)

8.3 The elastomer compound shall be selected for the fluid and temperature of the service.

Elastomer compoundselect

EPDM

Neoprene

Nitrile

NOTE EPDM is the default for water, glycol, and steam condensate; Neoprene suits general service; Nitrile is required where the water may be oil-contaminated. (8.3.1)

8.4 The default rubber sphere joint for hydronic HVAC shall be EPDM with nylon reinforcement, rated 150 psig and 200°F maximum, with Class 150 flanged ends and galvanized carbon-steel control rods.

8.5 Control rods shall be furnished on rubber joints to limit extension under pressure, in accordance with MSS SP-129.

Control rodsradio

● Furnished with control rods

○ Not required (verify with Engineer)

8.6 Control rods shall be set to allow full rated movement while stopping extension at 150% of working pressure.

NOTE Without control rods the joint can be over-extended at startup and fail. (8.7)

NOTE Control rods limit the joint's extension to its rated travel and prevent over-extension under full pressure or vacuum at zero-flow startup; an uncontrolled joint can be torn open before flow is even established, voiding the warranty. (8.7.1)

8.7.2 The rated working pressure of the rubber expansion joint shall be specified consistent with the pressure of the service in which it is installed.

Rated working pressurerange

psig

75250

Default: 150 psig

8.7.3 The maximum service temperature of the rubber expansion joint shall be specified consistent with the fluid, temperature, and elastomer compound selected for the service.

Maximum service temperaturerange

°F

120250

Default: 200 °F

8.7.4 The rated axial movement of each rubber expansion joint shall be specified, and control rods shall be provided to limit extension to that rating.

Rated axial movement (rubber)range

in

0.52

Default: 0.75 in

9 Slip Joints and Ball Joints

9.1 Slip/sleeve expansion joints shall be used in straight runs to absorb large axial movement where loops are impractical.

NOTE A slip joint tolerates no lateral misalignment and depends entirely on guides. (9.2)

NOTE A telescoping sleeve packed at a gland absorbs large axial travel - 2 to 12 in is standard - but binds and leaks if the pipe is allowed to deflect laterally; precise guide placement on both sides is mandatory, and the packing is a maintenance item that must be accessible. (9.2.1)

9.3 Slip joints shall be installed with the packing gland accessible for periodic adjustment and repacking.

9.4 Ball-joint pairs shall be used in pairs straddling a short offset to absorb angular and lateral movement where space is constrained.

Slip-joint rated axial travelrange

in

212

Default: 4 in

10 Fabricated Expansion Loops and Offsets

10.1 Fabricated loops and offsets shall be the same material, wall thickness, and pressure class as the run they serve.

10.2 Loop legs shall be sized for the calculated thermal movement of the run, with formal stress analysis where the governing code requires it.

NOTE A simplified leg-length estimate is adequate for routine low-temperature steel; code-governed runs need real analysis. (10.3)

NOTE For steel pipe a first-pass leg length is L (ft) ≈ √(3 × D × Δ / 0.00307), where D is pipe OD in inches and Δ is thermal movement in inches; this sets the size of the loop early in coordination. Steam, HTHW, and large-diameter runs require a formal ASME B31 analysis rather than the estimate. (10.3.1)

10.4 Loops require substantial perpendicular space and shall be coordinated in the BIM model before fabrication.

NOTE Loops are the most common RFI source for this standard when they are not coordinated with other trades. (10.5)

NOTE A U-loop needs roughly 2-4 ft of perpendicular leg per inch of growth, and that space routinely conflicts with ductwork, conduit, and structural beams in ceiling plenums; resolving the loop in the coordination model before fabrication prevents the field conflicts that otherwise generate change orders. (10.5.1)

10.6 The location, routing, and extent of each fabricated loop shall be as shown. expansion loop layout

10.7 L-offsets and Z-offsets formed at natural direction changes should be used to absorb expansion where the routing already provides a perpendicular leg.

Fabricated configurationradio

● U-loop (square or rectangular)

○ L-offset

○ Z-offset

Loop leg lengthrange

ft

220

Default: 6 ft

11 Anchors and Guides

11.1 Anchors and guides integral to an expansion device shall be furnished and located in accordance with EJMA and MSS SP-129.

Guide and anchor locationstext

Enter value...

Per drawings — anchor and guide layout (deferred by default)

NOTE Anchors direct movement; guides keep the pipe and bellows straight. (11.2)

NOTE Anchors fix the pipe at chosen points so that each device absorbs a defined movement; full (main) anchors resist full pressure thrust plus pipe weight and friction, while intermediate (directional) anchors divide a run into independently controlled segments. Guides allow free axial movement while preventing the pipe and bellows from buckling sideways. (11.2.1)

11.3 Main anchors shall be provided on both sides of every unrestrained metallic bellows joint and shall be designed for the full pressure thrust plus pipe weight and friction reactions.

Anchor type at deviceradio

● Full (main) anchor - resists full thrust

○ Intermediate (directional) anchor

NOTE Omitting or undersizing main anchors transfers pressure thrust into equipment and structure. (11.4)

NOTE When an unrestrained joint has no adequate main anchor, the pressure-thrust force (P × A_eff) is delivered straight into the nearest equipment nozzle or building element; this is a leading cause of field damage and RFIs and must never be left to chance. (11.4.1)

11.5 The first guide shall be located no more than 4 pipe diameters from the anchor face.

First guide distance from anchorrange

pipe dia.

14

Default: 4 pipe dia.

11.6 The second guide shall be located no more than 14 pipe diameters from the first guide.

11.7 Subsequent guides shall be spaced per the pipe-support span tables, typically 10-20 ft for water-filled steel.

NOTE Incorrect guide spacing allows the bellows to buckle under compression. (11.8)

NOTE Placing the first guide more than 4 pipe diameters from the anchor lets the bellows squirm - buckle sideways - under thermal compression load, a catastrophic and sudden failure mode. The 4D / 14D rule is not advisory. (11.8.1)

11.9 Anchor reaction loads shall be conveyed to the Structural Engineer of Record for design of beam and slab reinforcing at the anchor.

NOTE Coordinating anchor loads with the structural engineer is a commonly missed step. (11.10)

11.10.1 Full anchor forces combine pressure thrust, pipe weight, and friction and often require local reinforcing at the structural penetration; this coordination is routinely overlooked and shall be a tracked deliverable.

11.11 Expansion devices shall not be installed across building seismic joints or building separations.

NOTE Thermal joints are not designed for multi-directional seismic displacement; a separate seismic expansion coupling, coordinated through Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current edition.sync/hangers-and-supports, is required where piping crosses a building separation. (11.11.1)

12 Testing

12.1 Each metallic bellows joint shall be factory hydrostatically tested to 1.5 times its design pressure in accordance with ASME B31.1 Appendix P and EJMA.

12.2 Each rubber expansion joint shall be factory tested to 1.5 times its rated working pressure in accordance with ASTM F2686.

12.3 Each expansion device shall be installed in its cold-set position before the adjacent piping is field hydrostatically tested.

12.4 The cold-set, or cold-spring, offset shall be the value calculated by the manufacturer so the device operates near mid-travel at operating temperature.

NOTE Skipping the cold-set directive wastes half the device's rated travel. (12.5)

NOTE A joint installed neutral at ambient reaches one extreme of its travel at operating temperature and has nothing left for the return swing; pre-positioning it to the manufacturer's cold-set offset centers the travel band so the full rated movement is usable. Omitting this is a quiet design error that halves capacity. (12.5.1)

12.6 Devices shall not be over-compressed or fully extended during the field pressure test.

12.7 Shipping bars and other protective restraints shall be removed only after installation is complete and the system is ready for cold-set, per the manufacturer's instructions.

Factory test pressureradio

● 1.5 x design pressure (metallic, ASME)

○ 1.5 x rated working pressure (rubber, ASTM)

Cold-set required before field testradio

● Yes - install at manufacturer's cold-set offset

○ No cold-set (verify with Engineer)

13 Installation

13.1 Expansion devices shall be installed in strict accordance with the manufacturer's published installation instructions, which shall be included in the contract documents.

NOTE Installation instructions belong in the contract documents, not only in a box. (13.2)

NOTE Bolt torque sequence, shipping-bar removal order, and rubber-joint test-pressure limits are frequently absent from the drawings and generate RFIs during installation; including the manufacturer's instructions in the contract set closes that gap. (13.2.1)

13.3 Flanged joints shall be made up with the manufacturer's specified bolt torque sequence and full-face gaskets suited to the elastomer or metal face.

13.4 Expansion devices shall not be used to correct piping misalignment; the adjacent piping shall be independently aligned and supported before the device is connected.

13.5 An expansion joint shall not be used as a vibration isolator in place of a flexible pump connector.

NOTE Flexible pump connectors for vibration isolation are a separate product coordinated through Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current edition.sync/hangers-and-supports; expecting an expansion joint to isolate equipment vibration is a misapplication. (13.5.1)

13.6 Field-fabricated loops and any butt-welded joints shall be welded by welders qualified to the governing code.

14 Delivery, Storage, and Handling

14.1 Expansion devices shall be delivered with shipping bars and protective end covers in place and shall be left in place until installation.

14.2 Devices shall be stored indoors, protected from weather, ultraviolet exposure, and physical damage.

NOTE Rubber elastomers degrade under prolonged UV and ozone exposure, and bellows convolutions are easily dented; indoor, covered storage protects both until the device is installed. (14.2.1)

14.3 Rubber expansion joints shall not be stored compressed, stacked under load, or folded.

14.4 Devices shall be handled by the body or end fittings, never by the bellows convolutions or the elastomer sphere.

15 Warranty

15.1 The manufacturer shall warrant each expansion device against defects in materials and workmanship for the period specified.

Manufacturer warranty periodradio

○ 1 year

● 2 years

○ 5 years

NOTE Warranty coverage is preserved only when the device is installed within its rated movement and control limits. (15.2)

NOTE Most manufacturers void coverage if a joint is over-extended, over-compressed, or installed without the required control rods or cold-set; the installation requirements of this standard are also the conditions of the warranty. (15.2.1)

16 Spare Parts

16.1 The Contractor shall furnish the spare parts and maintenance materials specified for the installed devices.

Spare parts to furnishcheckbox

☑ Spare packing set per slip-joint size

☐ Spare control rods / hardware per rubber joint

☑ Spare gaskets per flanged connection size

16.2 Spare packing shall be furnished for slip/sleeve expansion joints.

NOTE Slip joints are the only covered device with a routinely replaceable wear part; a spare packing set per joint size keeps the system maintainable without a special order at the first repack. (16.2.1)