⛽ Checking for free water in liquefied petroleum gas (LPG) by visual inspection — the sample is transferred from the sample cylinder into a transparent 250 ml pressure cylinder filled to about half, cooled in a freezer for at least 1 h below 0 °C and inspected for ice lumps at the bottom; result “pass” (no ice) or “fail” (ice), PN-EN 15469

Petrochemistry PN-EN 15469

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN 15469:2009 (Polish version), in full (our translation): “A method is given for the use of a pressure cylinder to determine the presence of free water in liquefied petroleum gas (LPG) by visual inspection at a temperature below 0 °C”. We read the text of the standard in the sample of SIST EN 15469:2008 (the text of EN 15469:2007 without changes) in full: foreword and Clauses 1–9 (scope, term, principle, significance, apparatus, preparation of apparatus, procedure, report, precision); only the bibliography remains outside the sample, from which the text cites EN ISO 3993 as item [1].

ACCORDING TO THE TEXT OF EN 15469:2007 (foreword, Clauses 1–9). The standard was prepared by CEN/TC 19 “Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin” (secretariat NEN); approved by CEN on 7 October 2007. Scope (1): method using a pressure cylinder to determine the presence of free water in LPG by visual inspection below 0 °C. Term (2.1): liquefied petroleum gases (LPG) — petroleum gas that can be stored and/or handled in the liquid phase under moderate pressure and at ambient temperature, consisting predominantly of propane and butanes with small proportions of propene, butenes and pentanes/pentenes. Principle (3): the LPG sample is transferred into a transparent pressure cylinder filled to 50 % of its capacity, left below 0 °C for not less than 1 h and inspected for ice lumps; the result is given as “pass” if ice is absent or “fail” if ice is present. An LPG sample with dissolved and/or free water, at saturated vapour pressure and above 0 °C, is clear and does not become cloudy, which makes it difficult to distinguish the two liquid phases — both liquids are colourless and the separation surface can be seen at laboratory temperature only in a transparent container under optimal lighting; ice is far less transparent than water, so freezing improves the visibility of the water. Significance (4): the test detects liquid water transported with LPG; excess water in LPG can cause corrosion of equipment and can also separate and freeze, blocking valves, pumps and regulators. Apparatus (5): sample cylinder preferably with a bottom valve whose stem is short enough not to retain free water during transfer of the sample — if not possible, a classical cylinder is used with the procedure of 7.1.2; test cylinder — a transparent container of 250 ml capacity, suitable for the pressure of the product, with a thermometer in contact with the liquid, a bottom valve and a top vent valve (note: a transparent plastic or glass container as in EN ISO 3993 or any other transparent LPG container with bottom and top vent valves may be used); a freezer easily maintaining a temperature below 0 °C (note: a cooling bath is not appropriate for this test method). Preparation of apparatus (6): before cleaning, the test cylinder is emptied of the previous sample by removing the liquid phase rather than the vapour phase, so that no residue remains on the walls; it is cleaned with a suitable solvent (e.g. ethanol or isopropanol), dried with nitrogen or dry air, which is then removed by vacuum; the vacuum is released with dry vaporized butane; the closed cylinder is stored in dry conditions; it shall not be suspected to retain liquid (water or solvent) in the bottom valve. Procedure (7.1): the test cylinder at least 30 min in the freezer before transferring the sample; if the shape of the stem of the bottom valve of the sample cylinder may retain decanted water — shake the sample vigorously to disperse the droplets; immediately connect the bottom valve of the vertically standing sample cylinder to the inlet valve of the test cylinder with small-diameter tubing (so as not to introduce much air) and check for leaks; open the bottom valve of the sample cylinder, then the inlet valve of the test cylinder, if necessary slightly open the vent valve, and fill the test cylinder to about 50 % of its capacity; close all valves, disconnect the cylinder, check for leaks with valves closed — if leaks are found, the sample is discarded and sampling repeated with a repaired cylinder. Testing (7.2): the cylinder with the sample is placed horizontally in the freezer for at least 1 h (note: depending on the mass of the cylinder and the quantity of product, more time may be needed); after removal, make sure the temperature is below 0 °C and immediately observe the liquid for small ice lumps at the lower generatrix or at the bottom; if the walls are rapidly covered with frost from air humidity, wipe it off as fast as possible and observe again; record any presence of ice. Training note: it is useful to simulate a “fail” by adding 1 ml of water to the test cylinder and following the whole procedure — ice lumps will certainly appear and the operator will know what to look for; the same test is performed by introducing 1 ml of water into the sample cylinder, to check whether water is not trapped in it. Report (8): “pass” if ice is absent, “fail” if ice is present. Precision (9): it cannot be specified, because the test is a pass/fail test, not a quantitative measurement.

STATUS (catalogue cards as of 03.10.2026). The card of PN-EN 15469:2009 (Polish version, published 28-01-2009, 9 pages, price group E) has no “Withdrawn” header: Chemistry Sector, KT 222 Petroleum Products and Similar Products of Biological and Synthetic Origin, ICS 75.160.20, “Introduces: EN 15469:2007 [IDT]”, “Replaces: PN-EN 15469:2008 — English version”. The card of PN-EN 15469:2008 (English version) has the header “Withdrawn”: withdrawal date 28-01-2009, “Replaced by: PN-EN 15469:2009”. Both introduce the same EN 15469:2007 — the change concerns the language version, not the content. The PKN search engine (query “PN-EN 15469”, 03.10.2026) shows no other editions. The card of PN-C-96008:1998 (liquefied gases C3–C4 — requirements and test methods, KT 223), cited jointly by two laboratories, has no “Withdrawn” header; according to its scope the standard does not apply to liquefied gases used as vehicle fuel.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read 03.10.2026). The number 15469 appears in 9 records at 7 laboratories: AB 009, AB 079, AB 103, AB 474, AB 484, AB 1275, AB 1278. In the current scopes on the PCA website (read 03.10.2026, issues from 18.02.2026 to 25.09.2026) AB 079, AB 103, AB 484 and AB 1275 give “PN-EN 15469:2009”, AB 009 and AB 1278 — the designation alone without the year; for AB 474 (accreditation valid until 16-12-2027) the PCA page does not provide the scope document — here we rely only on the database copy (2009 edition). The “Laboratories” tab (“PN-EN 15469”) shows 6 laboratories — all except AB 103, where the designation stands after “PN-EN 589:2024-08 p. 6.2”; checked with the tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA scopes). “Presence of water”, “visual method”, in gaseous fuels — liquefied petroleum gases (LPG); AB 009 also covers the biocomponent bio propane-butane. In the database copy AB 474 calls this item “Water content”. AB 079 and AB 1275 cite the standard jointly with PN-C-96008:1998 p. 4.4.5, with the same methodology (presence of water, visual method); AB 103 — together with PN-EN 589:2024-08 p. 6.2. In the same scopes, next to it, are among others presence of hydrogen sulfide (PN-EN ISO 8819), copper corrosion (PN-EN ISO 6251), hydrocarbon composition (PN-EN 27941) and odour (PN-EN 589, Annex A).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Sampling and transfer: decanted water retained in a long stem of the bottom valve of the sample cylinder does not reach the test cylinder — a “pass” with water in the sample; hence shaking the sample (7.1.2) and the check with 1 ml of water introduced into the sample cylinder (sentence below the note to 7.2.4). Apparatus: water or solvent left in the bottom valve after cleaning gives ice that was not in the sample — a “fail” not caused by the sample (6); a cylinder emptied via the vapour phase instead of the liquid phase leaves residues on the walls (6). Cooling: a cooling bath is not appropriate (5.3); 1 h is the minimum — a heavier cylinder or more product need longer, and water that is not cooled enough will not freeze (7.2.1); inspection must take place immediately after removal, with the temperature below 0 °C (7.2.2). Inspection: frost on the walls hides the content — wipe it off and observe again (7.2.3); an operator who has never seen ice lumps may miss them — hence the training test with 1 ml of water. Result: the method gives only “pass/fail” and has no precision (3, 9) — a numerical “water content” value given with this reference does not come from this method.

WHAT WE DO NOT GIVE. We read the text of the standard in full (without the bibliography); the standard gives no freezer temperature other than the condition “below 0 °C”, no detection limit for water and no precision — so we do not give them either. Nor do we give the requirements for free water from product standards (PN-EN 589, PN-C-96008), because we have not read their text.

Method principle

Dissolved or free water in LPG at saturated vapour pressure and above 0 °C is invisible, because both liquids are colourless and clear; after cooling the sample in a transparent pressure cylinder below 0 °C, free water freezes into ice lumps visible at the lower generatrix or at the bottom — their absence gives the result “pass”, their presence “fail”.

Applications

• Liquefied petroleum gases (LPG, propane-butane) — quality control of gaseous fuels; 7 laboratories in PCA scopes
• Detection of liquid water transported with LPG, which can cause corrosion and freeze, blocking valves, pumps and regulators (Clause 4)
• Biocomponent bio propane-butane — in the scope of one laboratory

Key parameters

Standard

Standard number

PN-EN 15469:2009

Title (PL)

Przetwory naftowe — Wizualna metoda sprawdzania obecności wolnej wody w skroplonych gazach węglowodorowych

Title (EN)

Petroleum products — Test method for free water in liquefied petroleum gas by visual inspection

Step-by-step procedure

1. Preparation of the cylinder

   Empty of the previous sample via the liquid phase, clean with ethanol or isopropanol, dry with nitrogen or dry air, remove it by vacuum, release the vacuum with dry butane; bottom valve free of liquid. PN-EN 15469:2009 current (PKN catalogue card as of 03.10.2026).

2. Cooling and filling

   Empty test cylinder ≥ 30 min in the freezer; if necessary shake the sample cylinder; connect the bottom valve of the vertical sample cylinder to the inlet of the test cylinder and fill to about 50 %.

3. Leak tightness

   Close the valves, disconnect, check for leaks; if leaking, discard the sample and resample into a repaired cylinder.

4. Freezing and inspection

   Cylinder horizontally in the freezer ≥ 1 h (longer for a heavy cylinder); after removal check that the temperature is < 0 °C and immediately look for ice lumps at the lower generatrix or bottom; wipe off frost.

5. Result

   “Pass” — no ice, “fail” — ice present; no numerical value and no precision.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• LPG is extremely flammable and under pressure — tight connections, no ignition sources, leak check of the cylinder before and after filling (7.1.3, 7.1.6); the text of the standard we read contains no separate warnings
• A plastic or glass test cylinder must be suitable for the pressure of the product (5.2); storing LPG samples in a freezer requires an appliance approved for flammable substances

Frequently asked questions