⛽ Gasoline vapour pressure (ASVP, DVPE)

Petrochemistry PN-EN 13016-1

Overview

STATUS (as of 02.11.2026). PN-EN 13016-1:2024-11 — Polish version, published 14.01.2026, implements EN 13016-1:2024 [IDT]; it replaced PN-EN 13016-1:2018-05 (Polish and English versions). The PKN catalogue card has no withdrawal note — the standard is current. Changes in EN 13016-1:2024 compared with the 2018 edition (foreword): updated safety warning, 15.1 revised to include details for 250 ml and 1,000 ml sample containers, updated text of 15.2 and 15.3, and a new Annex C giving precision for 1,000 ml containers. The EN 13016 series also includes Part 2 (absolute vapour pressure between 40 °C and 100 °C) and Part 3 (triple expansion method); Part 1 is based on and was developed in parallel with IP 394 and ASTM D5191. The Reid method (ISO 3007) is a different method of determining vapour pressure and is not covered by this description.

SCOPE (clause 1). Determination of the air saturated vapour pressure (ASVP; total vapour pressure) exerted in vacuo by volatile, low-viscosity petroleum products, components, ethanol blends up to 85 % (V/V) and feedstocks containing air; the dry vapour pressure equivalent (DVPE) is calculated from the ASVP. Conditions: vapour-to-liquid ratio 4 : 1 and test temperature 37.8 °C. The apparatus is not wetted with water during the test, so the method is suitable for samples with or without oxygenates; dissolved water in the sample is not taken into account. The method is suitable for air-saturated samples with a DVPE between 15.5 kPa and 106.0 kPa — vapour pressures outside this range can be measured, but the precision has not been determined. The standard applies to fuels containing oxygenated compounds up to the limits of Council Directive 85/536/EEC and to ethanol-fuel blends with up to 85 % (V/V) ethanol.

DEFINITIONS (clause 3). ASVP — the pressure observed in vacuo, consisting of the partial pressure of the product (in the absence of non-dissolved water) and the partial pressure of dissolved air. DVPE — a value calculated by a statistical correlation formula, corresponding to the dry vapour pressure determined by the Reid method according to ASTM D4953.

WHY IT IS TESTED (introduction). Vapour pressure is a classification criterion for the safe handling and carriage of petroleum products, feedstocks and components, it is related to the potential for uncontrolled hydrocarbon emissions and is therefore subject to environmental scrutiny; vapour pressure limits also prevent pump cavitation during transfer. A fuel with a high vapour pressure can vaporize too readily in the fuel system (decreased flow to the engine, possible stoppage by vapour lock), while a fuel with a low vapour pressure vaporizes too little, causing difficult starting, slow warm-up and poor acceleration.

HOW THE TEST PROCEEDS (clauses 4–9). A cooled, air-saturated sample of known volume is injected into a thermostatically controlled evacuated chamber or into a chamber evacuated by a moving piston after the sample has been introduced; the chamber volume is five times that of the test portion introduced. After thermal equilibrium has been reached at 37.8 °C, the total pressure in the chamber — the vapour pressure of the sample plus the partial pressure of the dissolved air — is measured with a pressure sensor, and the DVPE is calculated with a correlation formula (clause 4). The chamber holds from 5 ml to 50 ml of liquid and vapour (accuracy ≤ 1 %), the vapour-to-liquid ratio must lie between 3.95 : 1 and 4.05 : 1, and the temperature is controlled to within ±0.1 °C; the pressure transducer has a range of at least 0–130 kPa, an accuracy of ≤ 0.8 kPa and a resolution of ≤ 0.1 kPa, and the vacuum pump (if needed) reduces the pressure in the chamber to below 0.01 kPa (clause 6). Substances of at least 99 % (m/m) purity are used to verify the apparatus: pentane, 2,2-dimethylbutane, 2,3-dimethylbutane, cyclopentane and toluene (clause 5). Samples are taken according to EN ISO 3170 without water displacement, into a sealed container of at least 250 ml capacity, at least 70 % (V/V) full (clause 7). The vapour pressure determination is the first test performed on a sample: the container is cooled to 0–1 °C, its filling is checked (70–80 % (V/V); below 70 % the sample is discarded), and the sample is air-saturated — the container is quickly opened and closed, shaken vigorously and returned to the cooling equipment for at least 2 min, three times in all (clause 8). Before the sample is introduced, the pressure in the evacuated chamber must be stable and not exceed 0.1 kPa (9.2).

LEGAL REQUIREMENTS. Motor petrols: vapour pressure (DVPE method) from 45.0 kPa to 60.0 kPa in the summer period (1 May – 30 September), from 45.0 kPa to 90.0 kPa in the transition period (1 March – 30 April and 1–31 October) and from 60.0 kPa to 90.0 kPa in the winter period (1 November – end of February); in the transition period the vapour lock index VLI = 10 DVPE + 7 E70 at most 1164 for petrols with up to 3.7 % (m/m) oxygen and 1150 for petrols with up to 2.7 % (m/m) oxygen (Regulation of the Minister of Climate and Environment of 26.06.2024 on quality requirements for liquid fuels, Journal of Laws 2024, item 1018, Annexes 1 and 2 items 15 and 19). The regulation on test methods for the quality of liquid fuels (Journal of Laws 2024, item 1058, Annex Part I point 14) describes the ASVP method — injection of a cooled, air-saturated sample into a chamber with a pressure not exceeding 0.1 kPa or into a chamber with a moving piston, and calculation of the DVPE from the ASVP — according to PN-EN 13016-1, and gives the VLI formula in point 16.

WHAT WE DO NOT GIVE HERE. The publicly available text of the standard ends at the beginning of calibration (10.1.1). We do not give the calibration and verification of the apparatus (clauses 10–11), the measurement procedure (clause 12), the DVPE correlation formula (clause 13), the expression of the result (clause 14) or the precision values (clause 15, Annexes A and C); the accepted reference values for the verification substances are in normative Annex B.

Method principle

A cooled, air-saturated sample of known volume is injected into a thermostatically controlled evacuated chamber or into a chamber evacuated by a moving piston after the sample has been introduced; the chamber volume is five times that of the test portion introduced (vapour-to-liquid ratio 4 : 1). After thermal equilibrium has been reached at 37.8 °C, the total pressure in the chamber — the sum of the vapour pressure of the sample and the partial pressure of the dissolved air (ASVP) — is measured with a pressure sensor.

The measured total vapour pressure is converted with a correlation formula into the dry vapour pressure equivalent (DVPE) (clause 4), which corresponds to the dry vapour pressure determined by the Reid method according to ASTM D4953 (definition 3.2).

Applications

• Motor petrols — vapour pressure (DVPE) 45.0–60.0 kPa in summer, 45.0–90.0 kPa in the transition period and 60.0–90.0 kPa in winter (Journal of Laws 2024, item 1018, Annexes 1 and 2 item 15); method according to Journal of Laws 2024, item 1058, Annex Part I point 14
• Calculation of the vapour lock index of petrols VLI = 10 DVPE + 7 E70 (Journal of Laws 2024, item 1058, Annex Part I point 16)
• Volatile, low-viscosity petroleum products, components and feedstocks containing air (clause 1)
• Fuels with oxygenates and ethanol-fuel blends with up to 85 % (V/V) ethanol (clause 1)
• Classification for safe handling and carriage of products; assessment of the potential for hydrocarbon emissions (introduction)

Key parameters

Standard

Standard number

PN-EN 13016-1:2024-11

Title (PL)

Ciekłe przetwory naftowe — Prężność par — Część 1: Oznaczanie prężności par nasyconych powietrzem (ASVP) i obliczanie równoważnika prężności par suchych (DVPE)

Title (EN)

Liquid petroleum products — Vapour pressure — Part 1: Determination of air saturated vapour pressure (ASVP) and calculated dry vapour pressure equivalent (DVPE)

Step-by-step procedure

1. Sampling

   According to EN ISO 3170, without the water displacement technique; automatic sampling (EN ISO 3171) is not recommended unless it has been shown not to lose light ends. Sealed container of at least 250 ml, at least 70 % (V/V) full; samples are protected from excessive temperatures, and samples in leaking containers are discarded (7.1–7.5).

2. Cooling and checking the filling

   The vapour pressure determination is the first test on the sample. The closed container is cooled to 0–1 °C, wiped dry and its filling checked: it should be 70–80 % (V/V) — below 70 % the sample is discarded, above 80 % the excess is poured out (sample once poured out is never returned) (8.1–8.4).

3. Air saturation

   The container at 0–1 °C is wiped, quickly opened and closed without letting water in, shaken vigorously and returned to the cooling equipment for at least 2 min; this is done three times in all (8.5–8.6). For referee testing only one test portion is taken from the container (8.1).

4. Preparation of the apparatus

   According to the manufacturer’s instructions; the pressure in the evacuated chamber must be stable and not exceed 0.1 kPa — otherwise residual volatile components or the calibration of the transducer are checked. The syringe is cooled to 0–1 °C with its outlet sealed (clause 9).

5. Calibration and verification of the apparatus

   The calibration of the pressure transducer is checked at 37.8 °C or at the temperature recommended by the manufacturer when indicated by quality control or reference fluid checks (10.1.1); further calibration and verification requirements (clauses 10–11, Annex B) — outside the available text.

6. Measurement and result

   Introduction of the test portion, equilibration at 37.8 °C and reading of the total pressure (ASVP) — clause 12; calculation of the DVPE with the correlation formula and expression of the result — clauses 13–14 (outside the available text).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The standard does not address all hazards associated with its use — safety measures are established by the user (warning in clause 1)
• Highly volatile petroleum products are cooled in a suitably safe refrigerator (6.2)
• Petrols and the verification substances (pentane, dimethylbutanes, cyclopentane, toluene) are flammable — precautions according to the safety data sheets

Frequently asked questions