SH/T 0635-1996 Sampling method for liquid petroleum products (semi-automatic method)

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Card type: Test method

1. Method number / full title / English name / replacement relationship

• Standard number: SH/T 0635-1996
• Chinese name: Sampling method for liquid petroleum products (semi-automatic method)
• English name: not provided in the available source
• Replacement relationship: not provided in the available source

2. Scope of application and non-applicability

• Scope of application: This standard specifies the method for taking samples of liquid petroleum and liquid petrochemical products from vertical oil tanks (Chapter 1).
• Not applicable: Not applicable to taking samples from horizontal oil tanks, tank cars, oil tankers, and pipeline transportation (Chapter 1).
• Sample use: The samples taken are suitable for inspecting the quality of the batch of uniform petroleum products; estimating the quality of non-uniform petroleum products; their density can be used for calculating oil quantity (Chapter 1).

3. Method principle

When fluid flows out from a thin-walled small hole, the linear velocity v (m/s) of the fluid flowing out of the thin-walled small hole and the height h (m) of the hole from the liquid surface conform to the relationship of formula (1):

v = f·√(2g·h) ……(1)

Where:

• f—— velocity coefficient of the fluid;
• g—— gravitational acceleration, m/s².

According to the above principle, a sampler is installed in the storage tank. The sampler can take equal amounts of sample at equal intervals, so that a representative sample can be collected from the sampling port at the bottom of the tank (Chapter 2).

4. Reagents and materials (purity / preparation)

not provided in the available source.

5. Instruments and equipment

5.1 Sampler (3.1)

Includes a sampling tube equipped with standard sampling holes, a sampling pump, and sampling valves, etc. (see Figure 1). Figure 1 Sampler schematic labels: 1- float; 2- sampling tube; 3- outlet valve; 4- inlet valve; 5- sampling valve; 6- sampling pump; 7- water sampling valve. Note 1): The sampler is supervised by the petroleum product standardization technical centralized unit and provided by Jinzhou Petrochemical Company Jinzhou Refinery.

5.2 Sample container (3.2)

Used to hold samples, the capacity is usually between 0.25～5 L, depending on the need. The sample container should not leak, be resistant to solvents, have sufficient strength, and have a suitable stopper. The following options are available:

• 3.2.1 Glass bottle: should be clean, dry, and equipped with a stopper that can seal. Cork stoppers should not be used for volatile liquids. If the oil product is light-sensitive, a dark glass bottle should be used. Glass bottles should not be used for samples with a Reid vapor pressure greater than 180 kPa.
• 3.2.2 Oil can: made of galvanized iron sheet. Before use, check for leakage and rust. The oil can should be clean, rust-free, and dry. When there are welds, rosin flux may only be used on the outer surface of the oil can for welding. Cork stoppers cannot be used. The oil can should be equipped with a screw cap with an oil-resistant gasket. The gasket can only be used once.
• 3.2.3 Plastic bottle: made of uncolored polyethylene. Wall thickness not less than 0.7 mm. It may be used when it does not affect the properties of the oil product being tested.

5.3 Sample cooler (3.3)

It can be made by winding stainless steel tubing with an inner diameter of 6～8 mm. The outlet end of the coil is used to connect to the sample container, and the inlet end should be equipped with a flange or connected to other suitable devices of the sampling valve. When in use, the cooling coil can be immersed in a suitable cooling medium.

6. Recommended operating conditions

not provided in the available source (for sampling pump operating frequency see Section 8 5.3, 5.4).

7. Sampling and sample preparation

not provided in the available source (for sampling operation see Section 8).

8. Analytical procedure

8.1 Safety precautions (Chapter 4)

• 4.1 The sampling pump and the pump inlet and outlet valves should be checked frequently to prevent leakage. The pump body should be overhauled once a year.
• 4.2 In areas where flammable vapors may be generated, operators should not wear shoes that can produce sparks or clothing made of synthetic fibers.
• 4.3 Lamps and flashlights should be explosion-proof.
• 4.4 When sampling, operators should stand on the upwind side to avoid inhaling toxic and harmful petroleum vapors.
• 4.5 When taking samples at higher temperatures, operators should wear protective gloves to prevent burns.
• 4.6 In winter, the inlet and outlet oil pipelines and pump body should be properly insulated to prevent the sample from solidifying due to cold or water from the bottom of the tank entering the pipeline and pump body, causing equipment damage from freezing and oil spill accidents.

8.2 Operating method (Chapter 5)

• 5.1 Before sampling, the operator should carefully inspect the sample container to ensure there is no leakage, it is clean and dry, and the sealing stopper is tight.
• 5.2 It is necessary to check whether the sampling pump is flexible and usable. When operating normally, check according to the following method: when the inlet and outlet valves are closed, shaking the sampling pump should be very laborious; when the inlet and outlet valves are open and the sampling pump is shaken, putting your ear close to the pipe wall, you can hear the sound of oil product flowing. When the sampling pump operates abnormally, it should be stopped and overhauled.
• 5.3 Check whether the sampling pump inlet and outlet valves are in the normally open state. Move the sampling pump handle at a reciprocating frequency of more than 30 times per minute for more than 30 s, so that all the oil stored in the sampling tube returns to the tank, forming an "empty tube".
• 5.4 While continuing to move the sampling pump handle at the frequency of 5.3, open the sampling valve, discharge more than 100 mL of oil head, discard it into a waste oil bottle, and then use the pre-prepared sample container to collect the sample to the specified amount.
• 5.5 Close the sampling valve, and at the same time stop moving the sampling pump.

9. Qualitative and quantitative and calculation formula

See Chapter 3 formula (1): v = f·√(2g·h). Where: f is the velocity coefficient of the fluid; g is the gravitational acceleration, m/s²; h is the height of the hole from the liquid surface, m; v is the linear velocity of the fluid flowing out of the thin-walled small hole, m/s. (In the original formula (1), the velocity coefficient symbol source-text extraction appears as "f", and the gravitational acceleration symbol source-text extraction appears as "『", requires confirmation against the source standard (source-text extraction).)

10. Precision

not provided in the available source.

11. Report

not provided in the available source.

12. Referenced documents

not provided in the available source.

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick Q&A