Containers for compressed or liquefied gas, of iron, steel or aluminium

1. Scope and Applicability

This PCR applies to the cradle-to-gate production of empty iron, steel, or aluminium pressure containers made to contain compressed, liquefied, or dissolved gas. Covered products include refillable or non-refillable cylinders, tubes, pressure drums, and comparable metal pressure receptacles when their principal pressure-retaining body is iron, steel, or aluminium.

The foreground boundary starts with accepted metal stock and other purchased inputs at the manufacturing site and ends with a conforming, empty container released at the factory gate. It covers shell forming, route-specific joining, required heat treatment, machining and opening preparation, cleaning and surface finishing, pressure and mechanical testing performed by the manufacturer, rejection, and final release. Gas production and filling, valve manufacture when the valve is supplied as a separate product, distribution, use, periodic inspection or requalification, repair, and end-of-life are outside this PCR.

Composite pressure vessels whose load-bearing structure is not principally iron, steel, or aluminium, aerosol dispensers, small gas cartridges, and stationary reservoirs or tanks not intended for compressed or liquefied gas are excluded. A dataset must declare the vessel family, refillability, material and alloy, manufacturing route, water capacity, service pressure, test pressure, applicable design/manufacturing standard, included accessories, surface finish, geography, and reporting period.

2. Product Category Identity

Field	Value
canonical_pcr_id	pcr.metal-products-machinery-and-equipment.fabricated-metal-products-except-machinery-and-equipment.containers-for-compressed-or-liquefied-gas-of-iron-steel-or-aluminium
classification_refs	CPC 3.0: 42220 (exact classification context)
covered_products	Empty iron, steel, or aluminium pressure receptacles for compressed, liquefied, or dissolved gas, including cylinders, tubes, pressure drums, and comparable metal containers
excluded_products	Filled gas packages; composite vessels not principally load-bearing metal; aerosol dispensers; gas cartridges; stationary non-gas tanks; separately supplied valves; use, requalification, repair, and end-of-life services
representative_product	Empty refillable steel or aluminium gas cylinder that has passed the declared manufacturing conformity tests
production_route	Seamless steel from billet or tube; welded steel from plate; seamless aluminium from alloy billet; route-specific heat treatment, finishing, testing, and release
market_state	Empty, finished, inspected, pressure-tested, marked where required, and ready for dispatch at the manufacturing gate

3. Reference Flow

Field	Value
What	Provide an empty metal pressure receptacle capable of containing the declared compressed, liquefied, or dissolved gas under the declared service conditions
How much	1 kg of accepted empty container product at the manufacturing gate
How well	Conforming to the declared material, water capacity, service pressure, test pressure, manufacturing route, inspection plan, and applicable design/manufacturing standard
How long or cycle	One factory-gate production output; service life and refill cycles must be declared for downstream use but are not modelled in this cradle-to-gate reference flow
reference_flow_link	1 kg net mass of conforming empty container output, excluding separately supplied gas and accessories unless explicitly included

Field	Value
Reference amount	1 kg
Reference product flow	Empty iron, steel, or aluminium container for compressed or liquefied gas
Reference flow property	Mass 93a60a56-a3c8-11da-a746-0800200b9a66
Reference unit group	Units of mass 93a60a57-a4c8-11da-a746-0800200c9a66
Reference unit	kg
Required qualifiers	vessel family; refillability; pressure-shell material and alloy; input stock form; seamless or welded route; water capacity; service pressure; test pressure; gas-service compatibility; design/manufacturing standard; inspection and test plan; included accessories; surface finish; net empty mass; production geography; reporting period

When constructing a foreground data package, every item in Required qualifiers must be declared in dataset metadata, process notes, the reference flow comment, the product description, or an equivalent field. Missing qualifiers make the reference flow incomplete.

4. Measurement and Unit Rules

rule_id	Applies to	Required property	Required unit	Rule
reference_mass	Reference product and mass-based material, waste, and emission rows	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Use calibrated net mass. Exclude contained gas, test water, removable transport packaging, and separately supplied accessories unless the declared product system explicitly includes them.
energy_conversion	Electricity and fuels	Net calorific value for energy reporting	MJ	Preserve measured purchase units and conversion factors. Report electricity in MJ using 1 kWh = 3.6 MJ; use supplier- or laboratory-specific net calorific value for fuels and disclose it.
gas_volume_conditions	Natural gas and industrial oxygen	Volume 93a60a56-a3c8-22da-a746-0800200c9a66	m3	Declare temperature, absolute pressure, gas composition, and compressibility convention for every volume record; convert all records to one declared reference condition before aggregation.
water_mass_conversion	Process and test water	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Prefer mass metering; when volume is measured, apply a documented density at the measured temperature and retain the raw volume and conversion record. Count net make-up only when water is recirculated.
piece_to_mass	Containers recorded by count	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Convert accepted pieces to net empty product mass using calibrated unit or batch weighing; retain piece count, tare definition, sample coverage, and variability.

5. System Boundary

Boundary Abstraction

Field	Value
declared_starting_condition	Accepted iron, steel, or aluminium stock and other purchased inputs at the manufacturing-site receiving gate
starting_condition_role	Foreground manufacturing starts after upstream production and delivery of purchased materials and energy carriers
product_classification_scope	Empty metal containers whose defining function is containment of compressed, liquefied, or dissolved gas
recursive_input_rule	If an already manufactured in-scope gas container is consumed as an input, record it as a purchased product with a separate upstream dataset; do not recursively reproduce its manufacturing inventory inside this foreground process
upstream_dataset_requirement	Link every purchased product, energy, and waste-treatment service to a geographically and technologically representative upstream dataset; disclose substitutions and data gaps
disclosure	Declare included operations, route, material/alloy, input stock form, testing standard, rejected product treatment, surface-finishing route, included accessories, cut-offs, allocation, geography, and time period

rule_id	Applies to	Rule	source_ids
sb_factory_gate	foreground manufacturing	Include all site operations from accepted stock through a conforming empty container at the factory gate, including forming, applicable joining and heat treatment, machining, cleaning/finishing, pressure testing, inspection, rejects, and directly attributable utilities, wastes, and emissions.	us-dot-49-cfr-178-37; us-dot-49-cfr-178-46; us-dot-49-cfr-178-50
sb_upstream_links	purchased inputs and services	Keep purchased-input production and external waste treatment outside the foreground gate but connect each crossing flow to an appropriate upstream or treatment dataset.	ec-pef-method-2021
sb_exclusions	downstream stages	Exclude gas filling, distribution, use, periodic inspection/requalification, repair, and end-of-life unless a broader study explicitly adds them as separate downstream processes.	un-cpc-3-0-structure-2025
sb_cutoff_disclosure	completeness	Do not apply an automatic mass, energy, or environmental-significance cut-off. Quantify and justify every excluded crossing flow and disclose the cumulative omission.	ec-pef-method-2021

6. Process Inventory Structure

Process Map

process_id	process_name	inclusion	inclusion_condition	role	quantitative_reference
material_preparation_and_shell_forming	Material preparation and pressure-shell forming	required		Foreground shell production	Accepted formed shell mass and route-specific metal balance
pressure_shell_joining	Pressure-shell seam and attachment joining	conditional	Include when the declared design uses a welded or brazed pressure shell or flux-cored welding for a qualifying joint	Foreground joining	Joined shell mass and qualified joint records
heat_treatment	Route-specific heat treatment	conditional	Include whenever the declared alloy, forming route, or manufacturing standard requires normalizing, quenching, tempering, solution treatment, ageing, stress relief, or another thermal cycle	Foreground material conditioning	Heat-treated shell mass and recorded furnace cycle
machining_cleaning_and_finishing	Machining, cleaning, and surface finishing	required		Foreground finishing	Finished shell surface and accepted pre-test container mass
inspection_pressure_test_and_release	Inspection, pressure test, marking, and release	required		Foreground conformity and product release	Net mass of conforming empty containers released

Process: Material preparation and pressure-shell forming (material_preparation_and_shell_forming)

Inputs

Product flows

Non-alloy steel billet feedstock (steel_billet)

Record purchased billet only for a qualified seamless-steel route using this stock form. Preserve grade, heat number, supplier, delivery state, and assigned batch.

• Selected flow: Billet 7de70586-42d8-40bb-a687-e0e0c05722e4
• Flow property / unit: Mass / kg
• Amount rule: Measured accepted billet mass issued to the declared production batch
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg conforming empty container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_balance
• Sources:

Seamless steel tube feedstock (seamless_steel_tube)

Record circular seamless steel tube only where the cylinder route starts from qualified tube stock. The Tiangong UUID remains unresolved because the audited candidates were pipeline, non-circular, seamed, or different-metal products.

• Selected flow: Circular seamless steel tube for pressure-cylinder manufacture
• Flow property / unit: Mass / kg
• Amount rule: Measured accepted seamless tube mass issued to the declared production batch
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg conforming empty container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_balance
• Sources:

Steel plate feedstock (steel_plate)

Record pressure-shell plate only for the declared welded-steel route. Preserve grade, thickness, heat number, supplier, and batch assignment.

• Selected flow: Steel Plate 421db3a5-394d-410b-8ebf-af23a37fc878
• Flow property / unit: Mass / kg
• Amount rule: Measured accepted steel plate mass issued to the declared welded-container batch
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg conforming empty container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_balance
• Sources:

Aluminium-alloy billet feedstock (aluminium_alloy_billet)

Record traceable aluminium-alloy billet only for a qualified seamless-aluminium route. Alloy, cast, heat-treatment batch, supplier, and delivery state are mandatory foreground qualifiers; the mass-based Tiangong UUID is unresolved.

• Selected flow: Aluminium-alloy billet for seamless gas-cylinder manufacture
• Flow property / unit: Mass / kg
• Amount rule: Measured accepted aluminium-alloy billet mass issued to the declared production batch
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg conforming empty container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_balance
• Sources:

Forming electricity (forming_electricity)

Record metered electricity assigned to cutting, heating, extrusion, drawing, spinning, pressing, and other shell-forming equipment without including heat-treatment or downstream finishing electricity.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Metered or reconciled electricity attributable to material preparation and shell forming
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted formed shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Oxygen for oxy-fuel preparation (cutting_oxygen)

Record oxygen only when oxy-fuel cutting, heating, or edge preparation is actually used in this process. Keep it separate from air and shielding gas.

• Selected flow: Industrial oxygen bd4b0f96-2090-4806-a648-335ab20ff401
• Flow property / unit: Volume / m3
• Amount rule: Metered or cylinder-balance oxygen attributable to the declared preparation route
• Value mode: Foreground record (foreground_record)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted formed shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Post-industrial steel forming scrap (forming_steel_scrap)

Record segregated steel offcuts, chips, and rejected formed steel shell material leaving the process. Do not include accepted product mass or scrap internally remelted without crossing the process boundary.

• Selected flow: Post-industrial steel scrap c143745d-be4f-4d8f-b403-2dcbfe685349
• Flow property / unit: Mass / kg
• Amount rule: Weighed steel scrap leaving shell forming, reconciled to the steel material balance
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg accepted formed steel shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_balance
• Sources:

Aluminium forming scrap (forming_aluminium_scrap)

Record segregated aluminium offcuts, chips, and rejected formed aluminium shell material leaving the process. Preserve alloy and contamination status.

• Selected flow: Aluminium Scrap 96c5f842-ea53-419b-b1cd-c02c479efb45
• Flow property / unit: Mass / kg
• Amount rule: Weighed aluminium scrap leaving shell forming, reconciled to the aluminium material balance
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg accepted formed aluminium shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_material_balance
• Sources:

Elementary flows

Process: Pressure-shell seam and attachment joining (pressure_shell_joining)

Inputs

Product flows

Flux-cored welding wire (flux_cored_wire)

Record flux-cored wire only for a qualified welding procedure that uses it. Preserve consumable grade, batch, deposited-metal compatibility, and joint assignment.

• Selected flow: Flux Cored Wire 1b74a576-06e0-4764-97ce-11a73f8a4752
• Flow property / unit: Mass / kg
• Amount rule: Issued mass minus verified return of unused wire for qualifying pressure-shell and attachment joints
• Value mode: Foreground record (foreground_record)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted joined shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_welding_consumables
• Sources:

Joining electricity (joining_electricity)

Record electricity metered or allocated to qualified welding and brazing equipment for the declared container route.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Metered or reconciled electricity attributable to pressure-shell and attachment joining
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted joined shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Elementary flows

Process: Route-specific heat treatment (heat_treatment)

Inputs

Product flows

Natural gas for furnace firing (heat_treatment_natural_gas)

Record gaseous natural gas only for heat-treatment equipment that actually consumes it. Declare gas composition, reference conditions, net calorific value, and furnace assignment.

• Selected flow: natural gas in the gaseous state 4f19ca0e-7b3b-11dd-ad8b-0800200c9a66
• Flow property / unit: Volume / m3
• Amount rule: Metered or supplier-reconciled natural gas consumed by qualifying heat-treatment cycles
• Value mode: Foreground record (foreground_record)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted heat-treated shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Diesel for furnace firing (heat_treatment_diesel)

Record diesel only where it is the actual heat-treatment fuel. Keep it separate from mobile-equipment diesel and declare grade, biogenic fraction, and net calorific value.

• Selected flow: Diesel fuel 9d258d75-6792-4f1c-9856-81602ed8f816
• Flow property / unit: Mass / kg
• Amount rule: Tank-balance or invoice-reconciled diesel consumed by qualifying heat-treatment cycles
• Value mode: Foreground record (foreground_record)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted heat-treated shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Heat-treatment electricity (heat_treatment_electricity)

Record electricity used by resistance, induction, controls, pumps, and fans assigned to the declared heat-treatment cycle. Do not double count electricity already represented through purchased heat.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Metered or reconciled electricity attributable to qualifying heat-treatment cycles
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted heat-treated shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Quench-water make-up (quench_water)

Record only fresh process-water make-up crossing the heat-treatment boundary. Recirculated water is not counted again.

• Selected flow: Process Water 94a04f7e-2d5c-41f0-b182-d54a3b373a02
• Flow property / unit: Mass / kg
• Amount rule: Metered make-up water assigned to qualifying quench operations, net of returned or recirculated water
• Value mode: Foreground record (foreground_record)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted heat-treated shell output
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_water_balance
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Elementary flows

Direct fossil carbon dioxide (heat_treatment_co2)

Record direct fossil carbon dioxide released from on-site combustion of natural gas or diesel assigned to heat treatment. Exclude upstream electricity emissions and avoid duplicating stack measurements with fuel-balance calculations.

• Selected flow: carbon dioxide (fossil) 08a91e70-3ddc-11dd-923d-0050c2490048
• Flow property / unit: Mass / kg
• Amount rule: Calculate from collected fuel consumption and verified fossil carbon content, or use validated stack measurement, with one method selected for the reporting period
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted heat-treated shell output
• Basis kind: Process output (process_output)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_direct_emissions
• Sources:

Process: Machining, cleaning, and surface finishing (machining_cleaning_and_finishing)

Inputs

Product flows

Sodium hydroxide for aqueous cleaning (cleaning_sodium_hydroxide)

Record sodium hydroxide only when it crosses the foreground boundary as the declared cleaning or pretreatment chemical. Preserve solution concentration and supplier state.

• Selected flow: Sodium hydroxide e0abcced-0611-4c24-9290-5a2c5a0c4169
• Flow property / unit: Mass / kg
• Amount rule: Active sodium hydroxide mass calculated from issued solution mass and measured concentration
• Value mode: Calculated value (calculated_value)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted finished container before pressure testing
• Basis kind: Process output (process_output)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_surface_chemicals
• Sources:

Cleaning-water input (cleaning_water)

Record process water used for washing, rinsing, and aqueous surface preparation. Count net make-up and keep it separate from pressure-test water.

• Selected flow: Process Water 94a04f7e-2d5c-41f0-b182-d54a3b373a02
• Flow property / unit: Mass / kg
• Amount rule: Metered net cleaning and rinse-water make-up assigned to the declared finishing route
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted finished container before pressure testing
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_water_balance
• Sources:

Powder coating input (powder_coating)

Record powder coating only when this finish is applied. Preserve resin chemistry, colour, batch, cured-film specification, and recovered-powder practice.

• Selected flow: Powder Coating 0c581697-0eed-4b86-a070-b94966eb7344
• Flow property / unit: Mass / kg
• Amount rule: Issued coating mass minus verified reusable powder returned to stock
• Value mode: Foreground record (foreground_record)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted powder-coated container before pressure testing
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_chemicals
• Sources:

Finishing electricity (finishing_electricity)

Record electricity assigned to machining, washing, drying, coating application, coating recovery, and curing within this process.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Metered or reconciled electricity attributable to machining, cleaning, and finishing
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted finished container before pressure testing
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Cleaning wastewater (cleaning_wastewater)

Record wastewater leaving aqueous cleaning and rinsing before off-site or on-site treatment. Preserve pH, principal contaminants, treatment state, and destination.

• Selected flow: Wastewater from cleaning f0402393-e82c-47e8-9cd8-a486c97f3e89
• Flow property / unit: Mass / kg
• Amount rule: Metered or mass-balanced cleaning wastewater crossing the process boundary
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted finished container before pressure testing
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_water_balance
• Sources:

Unrecovered powder-coating residue (powder_coating_waste)

Record only spent powder and unrecovered overspray leaving the process as waste. Do not count powder internally recovered and returned to the application system.

• Selected flow: Powder coating waste 9aa53a82-5462-400e-9096-efab7718201f
• Flow property / unit: Mass / kg
• Amount rule: Weighed powder-coating waste dispatched from the finishing process
• Value mode: Foreground record (foreground_record)
• Specificity: Route-specific (route_specific)
• Normalization basis: per 1 kg accepted powder-coated container before pressure testing
• Basis kind: Process output (process_output)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_chemicals
• Sources:

Elementary flows

Process: Inspection, pressure test, marking, and release (inspection_pressure_test_and_release)

Inputs

Product flows

Hydrostatic pressure-test water (pressure_test_water)

Record fresh process-water make-up for hydrostatic testing. Reused test water remains inside the process and is not counted again.

• Selected flow: Process Water 94a04f7e-2d5c-41f0-b182-d54a3b373a02
• Flow property / unit: Mass / kg
• Amount rule: Metered fresh test-water make-up net of recovered water during the reporting period
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg conforming empty container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_water_balance
• Sources:

Testing and release electricity (test_electricity)

Record electricity for pressure pumps, test controls, drying, marking, handling, and final inspection assigned to released containers.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Metered or reconciled electricity attributable to inspection, pressure testing, drying, marking, and release
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg conforming empty container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_energy_and_fuel
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Conforming empty metal gas container (reference_product)

This is the accepted empty pressure container released at the manufacturing gate. The Tiangong product-flow UUID is unresolved; the row remains mass-based and fully qualified by the declared product specification.

• Selected flow: Empty iron, steel, or aluminium container for compressed or liquefied gas
• Flow property / unit: Mass / kg
• Amount rule: Calibrated net empty mass of containers that passed all required inspections and tests
• Value mode: Calculated value (calculated_value)
• Specificity: Product-specific (product_specific)
• Normalization basis: 1 kg conforming empty container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_final_product_and_tests
• Sources:

Waste flows

Rejected steel container scrap (rejected_steel_container)

Record the net mass of rejected steel containers or destructive steel test specimens leaving the process as scrap. Prevent duplication with forming scrap.

• Selected flow: Post-industrial steel scrap c143745d-be4f-4d8f-b403-2dcbfe685349
• Flow property / unit: Mass / kg
• Amount rule: Weighed rejected steel container and destructive-test scrap dispatched from final inspection
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg conforming empty steel container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_final_product_and_tests
• Sources:

Rejected aluminium container scrap (rejected_aluminium_container)

Record the net mass of rejected aluminium containers or destructive aluminium test specimens leaving the process as scrap. Prevent duplication with forming scrap.

• Selected flow: Aluminium Scrap 96c5f842-ea53-419b-b1cd-c02c479efb45
• Flow property / unit: Mass / kg
• Amount rule: Weighed rejected aluminium container and destructive-test scrap dispatched from final inspection
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg conforming empty aluminium container output
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_final_product_and_tests
• Sources:

Elementary flows

7. Allocation and Co-product Handling

rule_id	Applies to	Rule	source_ids
al_subdivision_first	shared manufacturing operations	Avoid allocation by sub-metering, batch assignment, equipment time, furnace charge, surface area, joint length, test count, or another causal physical record before applying an allocation factor.	ec-pef-method-2021
al_shared_utilities	utilities serving multiple products	Allocate only the residual shared quantity using a documented causal driver. Mass may be used only when it represents resource demand; otherwise use machine time, thermal load, surface area, or another justified driver and disclose a sensitivity check.	ec-pef-method-2021
al_scrap	metal scrap outputs	Report steel and aluminium scrap as waste outputs at the point they leave the foreground process. Do not subtract an avoided-primary-metal credit from the foreground inventory; any recycling substitution belongs to an explicitly declared downstream method.	ec-pef-method-2021
al_rework	internal rework	Keep rework that does not cross the process boundary inside the batch balance and assign its incremental energy and material use to the resulting accepted output. Record material leaving the system as waste only once.

8. Foreground Data Collection, Calculation, and Quality Rules

Data Collection Protocols

protocol_id	process_id	flow_role	record_type	raw_fields	collection_method	unit	frequency	temporal_coverage	site_scope	aggregation_rule	quality_evidence
cp_material_balance	material_preparation_and_shell_forming	Each metal stock input and each segregated metal scrap output	Batch issue, weighment, return, scrap, and inventory record	row_id; material/alloy; heat/cast; supplier; opening stock; receipts; issued mass; returned mass; accepted work-in-process; scrap mass; batch; unit	Reconcile calibrated scales, stock ledger, production issue, and scrap dispatch records for each material and row_id	kg	Each batch with monthly closure	Complete reporting period	All in-scope forming operations	Sum only records assigned to the row and batch; prevent duplicate scrap assignment; normalize by accepted output	Scale calibration; material certificate; heat/cast traceability; stock reconciliation; scrap ticket
cp_welding_consumables	pressure_shell_joining	Flux-cored welding wire	Consumable issue and return record	row_id; consumable grade; batch; opening stock; receipts; issued mass; returned mass; joint/work order; accepted output	Reconcile stores and work-order records for each qualified welding procedure	kg	Each batch with monthly closure	Complete reporting period	In-scope joined pressure shells and attachments	Net consumption equals issue minus verified unused return; normalize by accepted joined-shell mass	Consumable certificate; qualified procedure; stores reconciliation; work order
cp_energy_and_fuel	material_preparation_and_shell_forming; pressure_shell_joining; heat_treatment; machining_cleaning_and_finishing; inspection_pressure_test_and_release	One electricity, natural-gas, diesel, or oxygen row	Meter, invoice, tank, or cylinder record	row_id; meter/source id; opening/closing reading or stock; receipts; returns; reference conditions; calorific value; equipment/process; batch; allocation driver	Read calibrated meters or reconcile supplier and stock records separately for each carrier and row_id	MJ; kWh; kg; m3	Each batch or monthly, with reporting-period closure	Complete reporting period	All directly controlled in-scope equipment	Apply declared unit conversion and causal allocation; never combine carriers; normalize to process or reference output	Calibration; invoice; tank/cylinder ledger; fuel specification; allocation worksheet
cp_water_balance	heat_treatment; machining_cleaning_and_finishing; inspection_pressure_test_and_release	One process-water input or cleaning-wastewater output	Meter and recirculation balance	row_id; meter id; opening/closing reading; make-up; recirculated; discharged; transferred; temperature; density; process; batch	Reconcile inlet, reuse, inventory, and discharge meters; sample composition where wastewater crosses the boundary	kg; m3	Each batch or monthly, with reporting-period closure	Complete reporting period	In-scope quench, cleaning, rinsing, and hydrostatic-test systems	Count only net make-up as input and boundary-crossing wastewater as output; convert volume to mass with documented density	Meter calibration; water balance; density record; wastewater analysis; discharge or transfer record
cp_surface_chemicals	machining_cleaning_and_finishing	Sodium hydroxide, powder coating, and powder-coating waste as separate rows	Chemical issue, concentration, recovery, return, and waste record	row_id; chemical/product; concentration; batch; opening stock; receipts; issued; recovered; returned; closing stock; waste mass; destination	Reconcile each named chemical independently using calibrated mass records and measured concentration	kg	Each batch with monthly closure	Complete reporting period	Declared cleaning and coating route	Calculate active sodium hydroxide separately; exclude reusable recovered powder from net input and waste; normalize by accepted finished output	Supplier specification; concentration test; scale calibration; stock balance; waste ticket
cp_direct_emissions	heat_treatment	Fossil carbon dioxide from on-site fuel combustion	Fuel-carbon balance or validated stack measurement	row_id; fuel quantity; fuel carbon content; biogenic fraction; oxidation basis; stack result; monitoring period; assigned furnace output	Use one declared method per emission and period; reconcile calculated and measured values when both exist without double counting	kg	Each furnace batch with annual/reporting-period closure	Complete reporting period	In-scope fuel-fired heat-treatment equipment	Apply cr_fossil_co2; allocate only assigned fuel or measured stack mass; normalize by accepted heat-treated output	Fuel analysis or supplier specification; calibrated meter; stack QA record; reconciliation worksheet
cp_final_product_and_tests	inspection_pressure_test_and_release	Accepted product and rejected steel or aluminium container rows	Test, inspection, weighment, marking, and rejection record	row_id; serial/lot; material; route; empty mass; water capacity; service pressure; test pressure; test method; result; rejection reason; scrap mass; release date	Link calibrated weighing and required inspection/test records to each serial number or production lot	kg; item; pressure unit as declared	Each item or prescribed lot	Complete reporting period	All in-scope containers released or rejected	Sum accepted net empty mass for the denominator; assign rejected material once by material; normalize all rows to accepted mass	Scale and pressure-gauge calibration; test certificate; material traceability; release authorization; rejection disposition

Calculation Rules

rule_id	Applies to	Formula or rule	Inputs	Output	source_ids
cr_reference_normalization	every inventory row	Normalized amount = reporting-period row quantity / reporting-period net mass of conforming empty containers released within the same product system.	Row quantity; accepted reference-product mass; product and period assignment	Quantity per 1 kg reference product
cr_active_sodium_hydroxide	cleaning_sodium_hydroxide	Active sodium hydroxide mass = solution mass × measured mass fraction of sodium hydroxide; keep carrier water in the water balance when material.	Issued solution mass; measured concentration	kg active sodium hydroxide
cr_fossil_co2	heat_treatment_co2	Fossil CO2 mass = fossil fuel mass × fossil carbon mass fraction × oxidation fraction × 44/12, or the equivalent calculation from standardized gas volume; do not add a stack result representing the same emission.	Fuel quantity; reference conditions or density; fossil carbon content; oxidation fraction	kg fossil carbon dioxide
cr_metal_balance	steel and aluminium material rows	For each material and batch, input mass = accepted work-in-process mass + returned reusable stock + reported scrap/waste + documented inventory change; investigate and disclose residual imbalance.	Material issue; return; accepted output; scrap; inventory change	Material-specific reconciliation and normalized flows
cr_recovered_powder	powder_coating; powder_coating_waste	Net powder input = issued powder − unused return; waste output = collected residue dispatched as waste; powder recovered and reused within the process is neither a new input nor a waste crossing.	Issue; unused return; recovered reuse; waste dispatch	kg powder input and kg powder-coating waste

Data Quality Requirements

requirement_id	Applies to	Requirement	Evidence
dq_product_identity	reference product	Maintain serial- or lot-level linkage among material/alloy, manufacturing route, water capacity, service pressure, test pressure, applicable standard, included accessories, empty mass, and release status.	Product specification; drawing; material certificate; test and release record
dq_primary_data	foreground processes	Use complete site-specific records for directly controlled material, energy, water, waste, test, and emission flows over one representative reporting period; explain missing records and substitutions.	Meter and stock reconciliation; invoices; production ledger; data-gap log
dq_temporal	all rows	Align numerator and accepted-output denominator to the same reporting period and exclude abnormal shutdown, commissioning, or trial production unless separately disclosed.	Production calendar; meter dates; batch mapping; exception log
dq_measurement	measured quantities	Use calibrated devices suitable for the quantity and retain raw readings, units, conversion factors, reference conditions, and correction records.	Calibration certificates; raw readings; conversion worksheet; QA approval
dq_completeness	all boundary crossings	Reconcile material, water, fuel, and product balances; document each exclusion and its cumulative significance rather than relying on an automatic cut-off.	Balance worksheets; exclusion register; completeness review
dq_upstream_matching	linked datasets	Match upstream datasets to material grade/state, energy carrier, geography, technology, and reference unit; disclose proxies and unresolved identities.	Supplier specification; dataset metadata; proxy justification

9. Validation Rules

rule_id	Applies to	Rule	source_ids
vr_identity_complete	reference product	Reject a data package that omits vessel family, refillability, shell material/alloy, stock form, seamless/welded route, water capacity, service pressure, test pressure, applicable standard, included accessories, surface finish, geography, reporting period, or net empty mass.	un-cpc-3-0-structure-2025; us-dot-49-cfr-178-37; us-dot-49-cfr-178-46; us-dot-49-cfr-178-50
vr_route_consistency	process inventory	Require each reported flow and process to match the declared route. A conditional row may be absent only when its operation or material is demonstrably not applicable; zero must not substitute for missing data.	us-dot-49-cfr-178-37; us-dot-49-cfr-178-46; us-dot-49-cfr-178-50
vr_test_traceability	inspection and release	Require traceable inspection and pressure/mechanical-test evidence at the frequency prescribed by the declared standard, and exclude failed containers from accepted output.	us-dot-49-cfr-178-37; us-dot-49-cfr-178-46; us-dot-49-cfr-178-50
vr_mass_balance	metals and finished product	Require separate steel and aluminium balances to close within the site's documented measurement uncertainty; investigate residuals and prevent double counting of forming scrap, destructive-test specimens, and rejected containers.
vr_energy_no_double_count	electricity and fuels	Reconcile process-level energy with facility totals and reject overlap among forming, joining, heat treatment, finishing, testing, purchased heat, and upstream electricity emissions.
vr_emission_no_double_count	direct fossil carbon dioxide	Accept either a validated fuel-carbon calculation or a representative stack result for the same source and period; if both exist, use one and retain the other as a reconciliation check.
vr_cutoff_and_allocation	completeness and shared operations	Require disclosed exclusions, allocation drivers, residual shared quantities, and sensitivity where the allocation choice can materially affect results.	ec-pef-method-2021

10. Published Dataset Profile

Field	Value
dataset_role	Cradle-to-gate foreground production dataset for empty iron, steel, or aluminium compressed- or liquefied-gas containers
downstream_use	secondary_dataset; background_dataset
allowed_use	Product LCAs, supply-chain models, procurement comparisons, and lifecycle models that match the declared vessel design, material, route, service conditions, geography, included accessories, and factory-gate boundary
excluded_use	Filled-gas packaging without a separate gas/filling model; composite vessels outside the scope; use-stage safety or lifetime claims; periodic requalification; repair; end-of-life; or comparison of containers with materially different pressure service without functional adjustment
required_metadata	canonical PCR id; CPC context; vessel family; refillability; material/alloy; stock form; route; water capacity; service pressure; test pressure; standard; inspection plan; accessories; finish; empty mass; geography; reporting period; allocation; cut-offs; source and dataset versions
required_quality_disclosure	Primary-data coverage; meter and scale calibration; material and test traceability; material/water/energy reconciliations; rejected-product handling; direct-emission method; allocation drivers; exclusions; proxies; unresolved UUIDs; uncertainty and representativeness
update_trigger	Change in alloy or stock form, forming/joining/heat-treatment route, vessel design or pressure class, testing standard, finish, included accessories, site energy or water system, allocation, geography, or representative reporting period

11. Data Sources

Source id	Type	Reference	Used for
un-cpc-3-0-structure-2025	Official guidance (official_guidance)	United Nations Statistics Division, CPC Version 3.0 Structure, 30 June 2025, https://unstats.un.org/unsd/classifications/Econ/Download/In%20Text/CPC_Ver_3.0_Structure_30Jun2025.csv (retrieved 2026-06-23; SHA-256 5cd2c1c4890dd6be16af48e9bb940fed48efff9865f39ff15edaa921da25fb7c)	Product classification identity and separation from non-pressure tanks
us-dot-49-cfr-178-37	Standard (standard)	U.S. Department of Transportation, 49 CFR 178.37, Specification 3AA and 3AAX seamless steel cylinders, https://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-178/subpart-C/section-178.37 (accessed 2026-09-05)	Seamless-steel scope, material traceability, manufacture, heat treatment, inspection, pressure testing, and rejection records
us-dot-49-cfr-178-46	Standard (standard)	U.S. Department of Transportation, 49 CFR 178.46, Specification 3AL seamless aluminium cylinders, https://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-178/subpart-C/section-178.46 (accessed 2026-09-05)	Seamless-aluminium scope, traceable stock, backward extrusion, solution heat treatment and ageing, pressure testing, and mechanical testing
us-dot-49-cfr-178-50	Standard (standard)	U.S. Department of Transportation, 49 CFR 178.50, Specification 4B welded or brazed steel cylinders, https://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-178/subpart-C/section-178.50 (accessed 2026-09-05)	Welded-steel scope, joining, material traceability, pressure testing, and mechanical testing
ec-pef-method-2021	Official guidance (official_guidance)	European Commission, Commission Recommendation (EU) 2021/2279 on the use of the Environmental Footprint methods, https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:32021H2279 (accessed 2026-09-05)	Functional-unit framing, system-boundary and cut-off disclosure, foreground data quality, and allocation hierarchy