GB/T 4985-2021 English PDF (GBT4985-2021)

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GB/T 4985-2021: Standard test method for needle penetration of petroleum waxes
GB/T 4985-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 75.140
CCS E 42
Replacing GB/T 4985-2010
Standard test method for needle penetration of petroleum
waxes
ISSUED ON: OCTOBER 11, 2021
IMPLEMENTED ON: MAY 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 5
4 Principle ... 6
5 Instruments and reagents ... 6
6 Specimen preparation ... 9
7 Test steps ... 9
8 Results report ... 10
9 Quality control ... 10
10 Precision and deviation ... 11
Bibliography ... 13
Standard test method for needle penetration of petroleum
waxes
WARNING -- Personnel using this document shall have practical experience in
formal laboratory work. The use of this document may involve certain hazardous
materials, equipment and operations, but it does not provide recommendations for
all safety issues related to this. Before using this document, the user is responsible
for formulating appropriate safety and protection measures and determining the
applicability of relevant regulatory restrictions.
1 Scope
This document describes a method for evaluating wax hardness by measuring the depth
of penetration of a standard needle into a wax specimen.
This document is applicable to petroleum wax with a needle penetration value not
greater than 250 1/10 mm. It can also be used to determine Fischer-Tropsch wax,
synthetic wax and bio-wax, etc. However, this document does not give the precision of
determining synthetic wax and bio-wax, etc.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 514-2005, Specification for liquid-in-glass thermometers for testing of
petroleum products
GB/T 2539, Determination of melting point of petroleum wax - Cooling curve
method
NB/SH/T 0843, Evaluation of test systems for the petrochemical industry Statistical
techniques
SH/T 0132, Determination method for petroleum wax congealing point
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 penetration of petroleum wax
The depth to which a standard needle vertically penetrates into a wax specimen under
specified conditions, expressed in 1/10 mm.
NOTE: For example, a reading of 85 on the penetrometer dial indicates a penetration value of 85
1/10 mm and a penetration depth of 8.5 mm.
3.2 penetrometer
An instrument (or device) for determining the consistency or hardness of a solid or
semisolid sample by measuring the depth to which a needle or cone of a specified
weight penetrates into the sample under a specified gravity.
4 Principle
Heat the specimen to at least 17°C above the expected freezing point or melting point,
melt it, and pour it into the molding machine. Cool it in the air under specified
conditions. Then control the temperature of the molded specimen at the test temperature
in a water bath. Use the standard needle of the penetrometer to penetrate the sample for
5 s under a load of 100 g. Measure its penetration. The test temperature can be selected
from any temperature in the range of 25°C~55°C. Commonly used are 25°C, 35°C,
40°C, 45°C or 55°C.
5 Instruments and reagents
5.1 Penetrometer
5.1.1 Penetrometer: The schematic diagram is shown in Figure 1. In this document, a
standard needle is used to measure the hardness of wax specimens. The total load
includes the standard needle, the slide bar and the 50 g weight, a total of 100 g.
5.1.2 Manual penetrometer: It is used to make the standard needle contact the specimen
surface and measure the penetration depth of the standard needle into the specimen
when the test is completed. When the indicator of the manual penetrometer reads "zero",
the needle tip shall be accurately placed on the surface of the wax specimen through the
adjustment device. One type of adjustment device is an adjustable test table. The other
type is an adjustable needle assembly. Either one is selected. The instrument is equipped
with a horizontal adjustment screw and a level to ensure that the slide shaft is in a
vertical position. When releasing the loaded standard needle, the standard needle shall
fall off without obvious resistance. The scale of the indicator shall be calibrated to 1/10
mm. The scale range shall be not less than 250 1/10 mm.
5.1.3 Automatic penetrometer: used to make the standard needle contact the surface of
the specimen. The penetration time is controlled by an automatic timing device when
5.7 Thermometer
It is a precision thermometer for measuring water bath temperature. It is a full
immersion type. The scale range is 25℃~55℃. It meets the requirements of GB-71
thermometer specified in GB/T 514-2005.
5.8 Brass plate
The specifications are 63.5 mm ± 1.6 mm in length, 38.0 mm ± 1.6 mm in width, and
6.4 mm ± 1.6 mm in thickness. It is used to support the sample when it is prepared for
molding. The plate is placed on an insulating material such as a cork or rubber stopper
during the cooling of the sample.
5.9 Reagent
Glycerol aqueous solution (50% by volume).
6 Specimen preparation
Heat the wax specimen to melt at least 17℃ above its expected freezing point
(determined by the method in SH/T0132) or melting point (determined by the method
in GB/T2539). Prevent local overheating. Ensure that the wax specimen is uniform and
free of bubbles. In a test room or test box (5.5) at 24.0℃ ± 2.0℃, place the brass plate
(5.8) on a stable support such as a rubber stopper or cork stopper. Then wet the upper
surface of the brass plate with the reagent (5.9). Place the specimen former (5.4) on the
brass plate. Then pour the molten wax specimen into the specimen former to form a
convex meniscus. Cool it at 24.0℃ ± 2.0℃ for 1 h. Scrape off the excess wax specimen
on the top of the specimen former. Remove the brass plate. Place the wax specimen
surface in contact with the brass plate facing up. Place it on a porous specimen holder.
Place in a water bath (5.6) at the test temperature ± 0.1 °C for 60 min. Very hard wax
may sometimes separate from the specimen former due to shrinkage. In this case, it is
permissible to use a wedge to plug the wax specimen in the former tightly.
7 Test steps
7.1 Manual penetrometer
7.1.1 Place the head of the manual penetrometer on the edge of the water bath (5.6) and
over the porous specimen holder that supports the specimen. A weight may be placed
on the base of the penetrometer to balance the head. Adjust the penetrometer and the
porous specimen holder in the water bath to a level position.
7.1.2 Ensure that the specimen former and porous specimen holder do not shake during
the test. Adjust the water bath surface to at least 25 mm above the upper surface of the
specimen. Maintain the test temperature (within ± 0.1°C). Before measuring each
sample, measure the temperature of the water bath using the thermometer specified in
5.7.
7.1.3 Add a 50 g weight to the standard needle so that the total mass of the standard
needle and its accessories is 100 g ± 0.15 g. Check whether the release device is stuck.
The indicator shall be at the "zero" position. Adjust the needle ...