Seven checks for dealers and users to spot a compliant LPG cylinder: stamped data, welds, body, paint, valve, tare weight and the records that come with it.
An LPG cylinder holds pressure for many years, so its quality directly affects users’ safety and the dealer’s reputation. Without special tools, the 7 checks below let dealers and users identify a compliant LPG cylinder and reject cylinders that show warning signs.
A compliant cylinder has data stamped on the collar or handle: the manufacturer’s name or mark, serial number, tare weight, capacity, test pressure, month and year of manufacture, and inspection date. The characters must be sharp, not ground off, re-punched or hidden under paint. A cylinder without a serial number or with erased data should be rejected immediately.
Cylinders in circulation must be periodically re-inspected according to the regulation; the latest inspection date is shown on the cylinder. A cylinder past its inspection date must not be filled until it is re-inspected. New batches come with inspection records from the manufacturer — see LPG cylinder inspection records.
A steel cylinder is welded from two body halves (plus the collar, foot ring and handle). A good weld runs evenly around the body with a continuous surface — no pores, no cracks, no overlapping repair beads. Cylinders showing manual weld repairs on the body should not be used.
Light scratches in the paint do not affect pressure resistance, but should be touched up to stop rust spreading.
A quality cylinder is surface-cleaned before powder coating, so the paint is uniform in colour and well bonded, with no blistering or peeling. Good paint protects the steel from rust throughout outdoor circulation and handling. For private-label cylinders, consistent colour between batches is also a sign the manufacturer controls its process well.
The valve is the part customers handle every day. Check that it is the right type (POL or QCC) for the customer’s regulator, that the thread and seal are undamaged, and that there is a protective cap for transport. After filling, test for leaks around the valve with soapy water — never use a flame. See also our LPG cylinder valves.
Weigh the empty cylinder and compare it with the stamped tare weight. A large difference may mean corrosion, repairs or incorrect markings. Typical tare weights: 12kg LPG cylinder about 13.5 – 15kg, 45kg LPG cylinder about 38 – 42kg depending on the specification.
| Check | Pass | Reject |
|---|---|---|
| Stamped data | Clear, serial and date present | Missing serial, ground off or re-punched |
| Inspection period | Valid | Expired |
| Welds | Even, continuous, no pores | Cracks, pores, repair beads |
| Body | Round and even, no dents | Deep dents, bulges, patchy rust |
| Paint | Even, well bonded | Peeling, blistering |
| Valve | Correct type, tight, capped | Leaking, damaged thread |
| Tare weight | Matches marking | Large difference |
Light scratches in the paint do not affect pressure resistance. Touch them up to prevent rust; if the scratch reaches the steel, or there are dents or patchy rust, have the cylinder assessed at inspection.
Buy from a manufacturer whose cylinders carry complete stamped data and come with batch inspection records; compare the serial numbers on the cylinders with the list in the records on delivery.
New cylinders have been pressure-tested at the factory. Dealers only need to check their appearance, stamped data and records on delivery; note any transport damage immediately on the delivery report.
VietnhatGas manufactures cylinders in batches with a 7-step quality control process and a pressure test on every cylinder — see our LPG cylinder manufacturing service or send a request on our quotation page.
Written by the VietnhatGas technical and sales team — a batch manufacturer of LPG cylinders. This content is for reference; regulations and standards may change, so please check the current texts.
A comparison of steel and composite gas cylinders covering construction, weight, durability, cost, inspection and how common each is in Vietnam, to help dealers choose the right type of cylinder.
Read articleA weak gas stove flame, a red or yellow flame or uneven burning can be caused by a nearly empty cylinder, the regulator, the hose, dirty burners or incorrect air adjustment. How to check each cause and when to call a technician.
Read articleHow long a 12kg gas cylinder lasts depends on the stove’s output and your cooking time. How to estimate your own gas use, how to tell a cylinder is running low by weighing it and tips for saving gas when cooking.
Read articleSend us the capacity, quantity and brand printing requirements — VietnhatGas will reply with a batch quotation.
