+---
+title: Expansion Fittings and Loops for Piping
+category: Mechanical / Piping & Pumps
+toc_depth: 3
+description: >
+ When to use: Selecting and installing devices and fabricated configurations that absorb thermal
+ growth in mechanical piping - metallic bellows joints (single, tied, hinged, gimbal,
+ pressure-balanced), slip/sleeve joints, rubber/elastomeric joints, ball-joint pairs, and fabricated
+ expansion loops (U-loops, L-offsets, Z-offsets) - for hydronic, steam and condensate, and domestic
+ hot-water recirculation systems, plus the anchors and guides integral to their function.
+ Not intended for: pipe material, pressure class, and insulation for hydronic systems
+ (sync/hydronic-piping), steam and condensate piping (sync/steam-and-condensate-piping), or
+ chilled/condenser water (sync/chilled-and-condenser-water-piping); hanger and seismic-brace hardware
+ itself (sync/hangers-and-supports); water-hammer/shock arrestors (sync/water-hammer-arrestors);
+ vibration-isolating flexible pump connectors (sync/hangers-and-supports); and structural building
+ expansion joints and HVAC duct expansion joints, which are outside mechanical-piping scope.
+---
+
+# Scope {toc}
+
+## 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. {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. {note}
+
+## Thermal movement is the controlling design action. {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. {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. {note}
+
+## Anchors and guides are included only to the extent they are integral to the function of a thermal-movement device. {note}
+
+### The hanger and brace catalog itself - rod sizing, clevis types, spring hangers, riser clamps, and seismic bracing - is specified in [[sync/hangers-and-supports]]; this standard cites it for guide and anchor hardware but does not repeat it. {note}
+
+## This standard applies to new construction and renovation, from small commercial through large institutional and industrial facilities. {note}
+
+## Pipe material, pressure class, joining method, and insulation for the host system are specified in the governing piping standard, not here. {note}
+
+### Hydronic systems are governed by [[sync/hydronic-piping]], steam and condensate by [[sync/steam-and-condensate-piping]], and chilled and condenser water by [[sync/chilled-and-condenser-water-piping]]. {note}
+
+## Water-hammer and hydraulic-shock arrestors are specified in [[sync/water-hammer-arrestors]] and are not a substitute for thermal-movement devices. {note}
+
+## Vibration-isolating flexible pump connectors are coordinated through [[sync/hangers-and-supports]]; an expansion joint is not a vibration isolator. {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. {note}
+
+# Referenced Standards {toc}
+
+## Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## 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 |
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### 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.
+
+```datasheet
+label: Action submittals required
+type: checkbox
+options:
+ - 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
+default:
+ - 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
+```
+
+### 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.
+
+### 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.
+
+```datasheet
+label: Formal pipe-stress analysis required
+type: radio
+options:
+ - Not required (B31.9 simplified rules apply)
+ - Required for steam and HTHW systems
+ - Required for all expansion-device runs
+default: Required for steam and HTHW systems
+```
+
+## Closeout Submittals {toc}
+
+### 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.
+
+```datasheet
+label: Closeout submittals required
+type: checkbox
+options:
+ - O&M data for each device
+ - Record drawings (anchors, guides, cold-set)
+ - Warranty documentation
+ - Field test reports
+default:
+ - O&M data for each device
+ - Record drawings (anchors, guides, cold-set)
+ - Warranty documentation
+ - Field test reports
+```
+
+## Informational Submittals {toc}
+
+### 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.
+
+```datasheet
+label: Informational submittals required
+type: checkbox
+options:
+ - Factory hydrostatic test certificates
+ - Material test reports / mill certs
+ - Welder qualification records
+default:
+ - Factory hydrostatic test certificates
+ - Welder qualification records
+```
+
+# Quality Assurance {toc}
+
+## Metallic bellows expansion joints shall be designed and manufactured in accordance with the EJMA Standards, 11th Edition, and the governing ASME B31 code.
+
+## ASME B31.1 Mandatory Appendix P shall govern metallic bellows joints in power-piping, steam, and high-temperature hot-water service. {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. {note}
+
+## Rubber and elastomeric expansion joints shall comply with ASTM F2686.
+
+## Application, anchor and guide arrangement, and field installation shall comply with MSS SP-129.
+
+## 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.
+
+## 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. {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. {note}
+
+# Environmental and Service Conditions {toc}
+
+## 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.
+
+## 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.
+
+## The thermal expansion coefficient varies by pipe material and is the single largest driver of calculated movement. {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. {note}
+
+## 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.
+
+### 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. {note}
+
+```datasheet
+label: System service
+type: select
+options:
+ - Chilled water
+ - Condenser water
+ - Hydronic hot water
+ - High-temperature hot water (HTHW)
+ - Low-pressure steam
+ - Condensate return
+ - Domestic hot-water recirculation
+default: Hydronic hot water
+```
+
+```datasheet
+label: Pipe material (sets thermal coefficient)
+type: select
+options:
+ - Carbon steel
+ - Stainless steel
+ - Copper
+ - CPVC
+default: Carbon steel
+```
+
+```datasheet
+label: Design pressure
+type: range
+min: 50
+max: 300
+step: 25
+unit: psig
+default: 150
+```
+
+```datasheet
+label: Maximum operating temperature
+type: range
+min: 60
+max: 400
+step: 10
+unit: °F
+default: 200
+```
+
+```datasheet
+label: Calculated thermal movement per run (ΔL)
+type: range
+min: 0.25
+max: 12
+step: 0.25
+unit: in
+default: 1
+```
+
+# Device Selection {toc}
+
+## The expansion-device type shall be selected on the basis of available space, pipe size, pressure, temperature, and the structural capacity available for anchors.
+
+## Fabricated loops and offsets are the preferred solution wherever space permits because they have no wear parts and require no maintenance. {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. {note}
+
+## The rubber sphere joint is the default for typical hydronic HVAC below 200°F. {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 80%-case default and the starting point unless temperature, pressure, or movement rules it out. {note}
+
+## Metallic bellows joints dominate steam and high-temperature hot-water service. {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. {note}
+
+## Elastomeric expansion joints shall not be used on steam or on any service exceeding the elastomer's rated temperature.
+
+## The expansion device type shall be selected as scheduled.
+
+```datasheet
+label: Expansion device type
+type: radio
+options:
+ - 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
+default: Rubber sphere expansion joint
+```
+
+## End-Connection and Pressure Class {toc}
+
+## The end-connection type and pressure class shall match the adjacent piping connection standard and the system pressure class.
+
+## A mismatched flange class makes the joint the weak link in the system. {note}
+
+### 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. {note}
+
+### Flanged connections shall conform to ASME B16.5 for the specified pressure class.
+
+```datasheet
+label: End-connection type
+type: radio
+options:
+ - Flanged
+ - Grooved / coupled
+ - Threaded
+ - Butt-weld
+default: Flanged
+```
+
+```datasheet
+label: Flange pressure class
+type: radio
+options:
+ - Class 150
+ - Class 300
+default: Class 150
+```
+
+# Metallic Bellows Expansion Joints {toc}
+
+## 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.
+
+## The bellows sub-type determines what movement the joint absorbs and whether it imposes pressure thrust on the anchors. {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. {note}
+
+## A single unrestrained joint shall be installed only between main anchors sized for the full pressure thrust.
+
+## 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.
+
+## Tied, hinged, gimbal, and pressure-balanced joints shall be used where the structure cannot accept the pressure-thrust reaction of an unrestrained joint.
+
+### Pressure-balanced joints are the appropriate choice on rooftops, suspended piping, and at equipment nozzles where no anchor structure can take the thrust load. {note}
+
+## Externally pressurized joints should be considered for large-diameter or high-pressure axial movement because the bellows convolutions are inherently resistant to squirm.
+
+## Bellows shall be austenitic stainless steel.
+
+### 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. {note}
+
+## The factory cycle-life rating shall meet or exceed the specified minimum for the service.
+
+## Building HVAC systems see a modest but real number of thermal cycles over their life, and the cycle rating must cover them with margin. {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. {note}
+
+```datasheet
+label: Bellows joint sub-type
+type: radio
+options:
+ - Single unrestrained (axial)
+ - Tied (lateral / angular)
+ - Hinged (single-plane angular)
+ - Gimbal (multi-plane angular)
+ - Pressure-balanced
+ - Externally pressurized
+default: Single unrestrained (axial)
+```
+
+```datasheet
+label: Bellows material
+type: select
+options:
+ - 304 stainless steel
+ - 316 stainless steel
+ - Nickel alloy (UNS N06625)
+default: 304 stainless steel
+```
+
+```datasheet
+label: Number of plies
+type: radio
+options:
+ - Single-ply
+ - Multi-ply
+default: Single-ply
+```
+
+```datasheet
+label: Rated axial movement
+type: range
+min: 0.5
+max: 12
+step: 0.5
+unit: in
+default: 2
+```
+
+```datasheet
+label: Minimum cycle life
+type: radio
+options:
+ - 3,000 cycles
+ - 5,000 cycles
+ - 10,000 cycles
+default: 3,000 cycles
+```
+
+# Rubber and Elastomeric Expansion Joints {toc}
+
+## 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.
+
+## The sphere type is compact and the spool type accommodates larger axial movement. {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. {note}
+
+## The elastomer compound shall be selected for the fluid and temperature of the service.
+
+### EPDM is the default for water, glycol, and steam condensate; Neoprene suits general service; Nitrile is required where the water may be oil-contaminated. {note}
+
+## 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.
+
+## Control rods shall be furnished on rubber joints to limit extension under pressure, in accordance with MSS SP-129.
+
+## Control rods shall be set to allow full rated movement while stopping extension at 150% of working pressure.
+
+## Without control rods the joint can be over-extended at startup and fail. {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. {note}
+
+```datasheet
+label: Rubber joint configuration
+type: radio
+options:
+ - Single-sphere
+ - Multi-sphere
+ - Spool (straight body)
+default: Single-sphere
+```
+
+```datasheet
+label: Elastomer compound
+type: select
+options:
+ - EPDM
+ - Neoprene
+ - Nitrile
+default: EPDM
+```
+
+```datasheet
+label: Rated working pressure
+type: range
+min: 75
+max: 250
+step: 25
+unit: psig
+default: 150
+```
+
+```datasheet
+label: Maximum service temperature
+type: range
+min: 120
+max: 250
+step: 10
+unit: °F
+default: 200
+```
+
+```datasheet
+label: Control rods
+type: radio
+options:
+ - Furnished with control rods
+ - Not required (verify with Engineer)
+default: Furnished with control rods
+```
+
+```datasheet
+label: Rated axial movement (rubber)
+type: range
+min: 0.5
+max: 2
+step: 0.25
+unit: in
+default: 0.75
+```
+
+# Slip Joints and Ball Joints {toc}
+
+## Slip/sleeve expansion joints shall be used in straight runs to absorb large axial movement where loops are impractical.
+
+## A slip joint tolerates no lateral misalignment and depends entirely on guides. {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. {note}
+
+## Slip joints shall be installed with the packing gland accessible for periodic adjustment and repacking.
+
+## Ball-joint pairs shall be used in pairs straddling a short offset to absorb angular and lateral movement where space is constrained.
+
+```datasheet
+label: Slip-joint rated axial travel
+type: range
+min: 2
+max: 12
+step: 1
+unit: in
+default: 4
+```
+
+# Fabricated Expansion Loops and Offsets {toc}
+
+## Fabricated loops and offsets shall be the same material, wall thickness, and pressure class as the run they serve.
+
+## Loop legs shall be sized for the calculated thermal movement of the run, with formal stress analysis where the governing code requires it.
+
+## A simplified leg-length estimate is adequate for routine low-temperature steel; code-governed runs need real analysis. {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. {note}
+
+## Loops require substantial perpendicular space and shall be coordinated in the BIM model before fabrication.
+
+## Loops are the most common RFI source for this standard when they are not coordinated with other trades. {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. {note}
+
+## The location, routing, and extent of each fabricated loop shall be as shown. [[drawing: expansion loop layout]]
+
+## L-offsets and Z-offsets formed at natural direction changes should be used to absorb expansion where the routing already provides a perpendicular leg.
+
+```datasheet
+label: Fabricated configuration
+type: radio
+options:
+ - U-loop (square or rectangular)
+ - L-offset
+ - Z-offset
+default: U-loop (square or rectangular)
+```
+
+```datasheet
+label: Loop leg length
+type: range
+min: 2
+max: 20
+step: 1
+unit: ft
+default: 6
+```
+
+# Anchors and Guides {toc}
+
+## Anchors and guides integral to an expansion device shall be furnished and located in accordance with EJMA and MSS SP-129.
+
+## Anchors direct movement; guides keep the pipe and bellows straight. {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. {note}
+
+## 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.
+
+## Omitting or undersizing main anchors transfers pressure thrust into equipment and structure. {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. {note}
+
+## The first guide shall be located no more than 4 pipe diameters from the anchor face.
+
+## The second guide shall be located no more than 14 pipe diameters from the first guide.
+
+## Subsequent guides shall be spaced per the pipe-support span tables, typically 10-20 ft for water-filled steel.
+
+## Incorrect guide spacing allows the bellows to buckle under compression. {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. {note}
+
+## Anchor reaction loads shall be conveyed to the Structural Engineer of Record for design of beam and slab reinforcing at the anchor.
+
+## Coordinating anchor loads with the structural engineer is a commonly missed step. {note}
+
+### 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. {note}
+
+## Expansion devices shall not be installed across building seismic joints or building separations.
+
+### Thermal joints are not designed for multi-directional seismic displacement; a separate seismic expansion coupling, coordinated through [[sync/hangers-and-supports]], is required where piping crosses a building separation. {note}
+
+```datasheet
+label: Anchor type at device
+type: radio
+options:
+ - Full (main) anchor - resists full thrust
+ - Intermediate (directional) anchor
+default: Full (main) anchor - resists full thrust
+```
+
+```datasheet
+label: First guide distance from anchor
+type: range
+min: 1
+max: 4
+step: 0.5
+unit: pipe dia.
+default: 4
+```
+
+```datasheet
+label: Guide and anchor locations
+type: text
+drawing_ref: anchor and guide layout
+default: deferred
+```
+
+# Testing {toc}
+
+## 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.
+
+## Each rubber expansion joint shall be factory tested to 1.5 times its rated working pressure in accordance with ASTM F2686.
+
+## Each expansion device shall be installed in its cold-set position before the adjacent piping is field hydrostatically tested.
+
+## 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.
+
+## Skipping the cold-set directive wastes half the device's rated travel. {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. {note}
+
+## Devices shall not be over-compressed or fully extended during the field pressure test.
+
+## 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.
+
+```datasheet
+label: Factory test pressure
+type: radio
+options:
+ - 1.5 x design pressure (metallic, ASME)
+ - 1.5 x rated working pressure (rubber, ASTM)
+default: 1.5 x design pressure (metallic, ASME)
+```
+
+```datasheet
+label: Cold-set required before field test
+type: radio
+options:
+ - Yes - install at manufacturer's cold-set offset
+ - No cold-set (verify with Engineer)
+default: Yes - install at manufacturer's cold-set offset
+```
+
+# Installation {toc}
+
+## Expansion devices shall be installed in strict accordance with the manufacturer's published installation instructions, which shall be included in the contract documents.
+
+## Installation instructions belong in the contract documents, not only in a box. {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. {note}
+
+## 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.
+
+## Expansion devices shall not be used to correct piping misalignment; the adjacent piping shall be independently aligned and supported before the device is connected.
+
+## An expansion joint shall not be used as a vibration isolator in place of a flexible pump connector.
+
+### Flexible pump connectors for vibration isolation are a separate product coordinated through [[sync/hangers-and-supports]]; expecting an expansion joint to isolate equipment vibration is a misapplication. {note}
+
+## Field-fabricated loops and any butt-welded joints shall be welded by welders qualified to the governing code.
+
+# Delivery, Storage, and Handling {toc}
+
+## Expansion devices shall be delivered with shipping bars and protective end covers in place and shall be left in place until installation.
+
+## Devices shall be stored indoors, protected from weather, ultraviolet exposure, and physical damage.
+
+### 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. {note}
+
+## Rubber expansion joints shall not be stored compressed, stacked under load, or folded.
+
+## Devices shall be handled by the body or end fittings, never by the bellows convolutions or the elastomer sphere.
+
+# Warranty {toc}
+
+## The manufacturer shall warrant each expansion device against defects in materials and workmanship for the period specified.
+
+## Warranty coverage is preserved only when the device is installed within its rated movement and control limits. {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. {note}
+
+```datasheet
+label: Manufacturer warranty period
+type: radio
+options:
+ - 1 year
+ - 2 years
+ - 5 years
+default: 2 years
+```
+
+# Spare Parts {toc}
+
+## The Contractor shall furnish the spare parts and maintenance materials specified for the installed devices.
+
+## Spare packing shall be furnished for slip/sleeve expansion joints.
+
+### 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. {note}
+
+```datasheet
+label: Spare parts to furnish
+type: checkbox
+options:
+ - Spare packing set per slip-joint size
+ - Spare control rods / hardware per rubber joint
+ - Spare gaskets per flanged connection size
+default:
+ - Spare packing set per slip-joint size
+ - Spare gaskets per flanged connection size
+```