Receiving a Refrigerant Delivery: Net-Weight Verification and Pre-Unloading Checks (49 CFR/IMDG/CISG)
· QUZHOU HUAFU NEW REFRIGERATION MATERIAL CO., LTD.
Receiving a Refrigerant Delivery: Net-Weight Verification and Pre-Unloading Checks (49 CFR/IMDG/CISG)
You cannot count your way to the right quantity in a refrigerant delivery. Two cylinders with the same product can differ in tare weight, so quantity is verified by weighing — and the check has to happen before the cylinders leave the truck.
1. Why “how many cylinders” is not a quantity
Cylinders are sold with a net contents figure, and the physical cylinder is not part of the product:
| Term | Meaning | Where it appears |
|---|---|---|
| Gross weight | Cylinder + valve + residual + product | What a scale shows on arrival |
| Tare weight (TW) | The empty cylinder as built and stamped | Marked on the cylinder |
| Net contents | gross − tare | The invoiced quantity (kg) |
⇒ The arithmetic is trivial and it is the only verifiable quantity check:
| Step | Action |
|---|---|
| 1 | Weigh the cylinders as received (per cylinder, or pallet + tare of the pallet) |
| 2 | Read TW off each cylinder and subtract |
| 3 | Compare the total net mass against the packing list and invoice |
| 4 | Record the numbers on the delivery receipt before signing |
⇒ Why it matters in practice: fill-to-net-weight is the industry method, so a shortfall shows up as a weight difference, not as a missing cylinder. A delivery “one cylinder short” is visible; a delivery 2 % light in every cylinder is not — unless you weigh. The declared net weight also has to sit inside the fill limit for the gas (filling ratios and temperature compensation).
2. Read the markings before you unload
Every transport cylinder carries a permanent set of markings on the shoulder or the neck. In US practice these are set out in 49 CFR 178.35 (initial qualification at the point of build) and 180.213 (re-qualification):
| Marking | What it tells the receiver |
|---|---|
| Specification / design code | The pressure vessel standard the cylinder was built to |
| Service pressure | Basis for the filling limit and for the fill-ratio check |
| Serial number | Ties the cylinder to its own filling and test history |
| Cylinder build date | Age; and it anchors the retest cycle (retest and requalification) |
| Requalification mark (e.g. “5A 2026”, with the requalifier’s registered symbol / RIN) | The retest date, together with the identifier of the requalifier that certified it (49 CFR 180.213) — an out-of-test cylinder must not be filled |
| TW (tare weight) | Required for §1 above; if it is not legible, the quantity check is impossible |
| UN number + proper shipping name | UN 3159 — 1,1,1,2-Tetrafluoroethane (Refrigerant gas R 134a), Class 2.2 |
⇒ The rule of thumb: if a marking that the quantity check depends on — TW particularly — is unreadable, ask for it in writing (the filling record) before unloading. Once the cylinders are in your rack, the argument about the delivered mass becomes a matter of opinion.
3. The five checks that are cheaper before unloading than after
| # | Check | Failure signal |
|---|---|---|
| 1 | Valve, cap and tamper indication intact | Open valve, missing cap, disturbed seal |
| 2 | Visible damage — dents, corrosion at the base, frost on a supposedly ambient cylinder | Damage or leakage in transit |
| 3 | Labels and class markings legible and matching the packing list | Wrong class or mislabelled product |
| 4 | COA lot number matches the cylinder batch on the packing list | Certificate for a different lot |
| 5 | Weigh-in (§1) | Mass shortfall |
⇒ Check 4 is the one most often skipped and the most expensive: a COA is only evidence for the lot it names. A certificate quoting a “typical analysis” without a lot identifier certifies nothing about your cylinders.
4. Keep four things, and start the clock
| Keep | Why |
|---|---|
| The weight ticket (per cylinder, or pallet-based with the calculation shown) | The primary evidence of the quantity actually delivered |
| Photographs at unloading — markings, valve, label, and any damaged cylinder | Evidence that cannot be recreated later |
| The packing list showing UN number, class and net mass per cylinder group | Links the documents to the goods; a list saying only “refrigerants” cannot be checked |
| A written discrepancy notice to the supplier, promptly | Under the CISG the buyer must give notice of non-conformity within a reasonable time of discovery (Art. 39) — the outer limit is two years from delivery, but “reasonable time” is the clause that actually decides claims |
⇒ The practical sequencing: weigh → photograph → notify in writing → then unload into stock and settle commercial terms. A claim raised after the product has been mixed into stock, or after several weeks of silence, is a substantially weaker claim — and usually a goodwill negotiation.
5. What a supplier can do to make the receiver’s check arithmetic
Two things make the arriving check possible instead of arguable:
- A weight ticket per cylinder (or per pallet, with the tare of each cylinder listed) — the receiver re-weighs and compares, no interpretation needed.
- A packing list by cylinder group carrying UN number, transport class and net mass — which also lets the receiving warehouse keep different classes physically segregated without re-sorting (storage and segregation).
⇒ This is the difference between a delivery that is accepted in ten minutes and one that opens a three-week correspondence.
What we can provide
The documents this article’s checks depend on can travel with the delivery: a per-cylinder weight ticket (gross, tare and net), a packing list stating the UN number, transport class and net mass per cylinder group, and a COA whose lot number matches the group it is issued for — so the weigh-in and the lot check become arithmetic instead of a correspondence. Stowage with the classes physically separated is supplied on request.
Contact us with: the product, the cylinder size and net mass required, the destination, and whether your warehouse needs classes stowed separately.
Sources
- 49 CFR 178.35 / 180.213 / 180.209 — US DOT cylinder markings, requalification markings and requalification intervals (PHMSA / eCFR).
- IMDG Code (IMO) / ADR (UNECE) — UN numbers, proper shipping names and classes for UN 3159, UN 3252, UN 3163 and UN 1593.
- CISG Article 39 — notice of non-conformity (UNCITRAL); the contract between the parties governs any claim.
Prepared by Quzhou Huafu New Refrigeration Material Co., Ltd — a warehousing and filling operation (storage and cylinder filling/repacking), not a manufacturer. The marking, retest and transport references above are to publicly available frameworks (49 CFR 178.35 / 180.213, IMDG, CISG Art. 39); site-specific requirements and any claim remain subject to the applicable law and the contract between the parties.
Need current specs, quota status, or a mixed-load quote for Net-Weight Verification and Pre-Unloading Checks (49 CFR/IMDG/CISG)? Contact sales@hufluor.com with your spec & destination port.