1.1 This standard specifies the method of sampling liquid hydrocarbon, oil tank residue and precipitate specimen from the fixed oil tank, railway tank wagon, road tank car, tank vessel, lighter, barrel and can, or from the pipeline for transporting liquid (see 4.3) through manual sampling.
1.2 This standard is applicable to sampling from the liquid petroleum products, crude oil and intermediate products in the storage oil tank or in transporting pipeline; the in-tank pressure shall be normal pressure or approach to normal pressure, and the petroleum or liquid petroleum products sampled shall in liquid state during ambient temperature up to 100℃.
The sampling method specified in this standard is not applicable to the analytic sampling for special features of the petroleum specialties. For this type of oil products, the analytical sampling of special features shall be in accordance with the provisions in relevant standards: for example, there are special requirements on sampling from electric insulating oil, liquid petroleum gas, LNG, asphalt and chemical products as well as unstable crude oil with Reid vapor pressure higher than 180 kPa (1.8 bar).
1.3 The basic manual samplings are:
a) Tank sampling;
b) Pipeline sampling.
While oil products are received or shipped, they either adopt tank sampling or pipeline sampling, or both. If two samplings are both adopted, the two sets of specimen shall be separated.
1.4 This standard specifies the method of minimizing or eliminating the light component loss in the specimen. During the sample treatment or transfer, aforesaid losses may appear which may the specimen loss its representativeness.
1.5 If the method applicable to sampling representative sample from the storage or moving even petroleum liquid is applied to sampling specimen from uneven liquids which has distinctive differences in composition, precipitate and (or) moisture content, the specimen sampled may loss its representativeness.
1.6 The sampling methods specified in this standard are applicable to sampling for the following purposes:
a) Determining the product quality;
b) Determining the water content in the oil products;
c) Determining other pollutants in the transported liquids.
If the sampling conditions in a), b) and c) have differences, the specimen shall be sampled independently.
1.7 This standard also specifies the sampling method of determining the degree of unevenness in the uneven oil product in the tank and estimating its quality and quantity.
1.8 This standard also specifies the method of sampling residue and precipitate from the tank, and the sampling technique of sampling under the pressure of inert gases.
Foreword I ISO Foreword II 1 Scope 2 References 3 Definitions 4 Sampling principles 5 Apparatus 5.1 Summary 5.2 Tank sampler 5.3 Barrel and can sampler 5.4 Pipeline sampler 5.5 Vessel 5.6 Vessel sealer 5.7 Sample cooler 6 Safety precautions 6.1 Summary 6.2 Equipment 6.3 Sampling point 6.4 Static 7 Operation methods 7.1 Introduction 7.2 Precautions 7.3 Tank sampling 7.4 Package sampling 7.5 Pipeline sampling 8 Sampling methods for crude oil and other uneven petroleum liquids 8.1 Summary 8.2 Sampling method 9 Sample handling 9.1 Summary 9.2 Sample equalization 9.3 Inspection on mixing time 9.4 Sample transfer
1.1 This standard specifies the method of sampling liquid hydrocarbon, oil tank residue and precipitate specimen from the fixed oil tank, railway tank wagon, road tank car, tank vessel, lighter, barrel and can, or from the pipeline for transporting liquid (see 4.3) through manual sampling.
1.2 This standard is applicable to sampling from the liquid petroleum products, crude oil and intermediate products in the storage oil tank or in transporting pipeline; the in-tank pressure shall be normal pressure or approach to normal pressure, and the petroleum or liquid petroleum products sampled shall in liquid state during ambient temperature up to 100℃.
The sampling method specified in this standard is not applicable to the analytic sampling for special features of the petroleum specialties. For this type of oil products, the analytical sampling of special features shall be in accordance with the provisions in relevant standards: for example, there are special requirements on sampling from electric insulating oil, liquid petroleum gas, LNG, asphalt and chemical products as well as unstable crude oil with Reid vapor pressure higher than 180 kPa (1.8 bar).
1.3 The basic manual samplings are:
a) Tank sampling;
b) Pipeline sampling.
While oil products are received or shipped, they either adopt tank sampling or pipeline sampling, or both. If two samplings are both adopted, the two sets of specimen shall be separated.
1.4 This standard specifies the method of minimizing or eliminating the light component loss in the specimen. During the sample treatment or transfer, aforesaid losses may appear which may the specimen loss its representativeness.
1.5 If the method applicable to sampling representative sample from the storage or moving even petroleum liquid is applied to sampling specimen from uneven liquids which has distinctive differences in composition, precipitate and (or) moisture content, the specimen sampled may loss its representativeness.
1.6 The sampling methods specified in this standard are applicable to sampling for the following purposes:
a) Determining the product quality;
b) Determining the water content in the oil products;
c) Determining other pollutants in the transported liquids.
If the sampling conditions in a), b) and c) have differences, the specimen shall be sampled independently.
1.7 This standard also specifies the sampling method of determining the degree of unevenness in the uneven oil product in the tank and estimating its quality and quantity.
1.8 This standard also specifies the method of sampling residue and precipitate from the tank, and the sampling technique of sampling under the pressure of inert gases.
Contents of GB/T 4756-1998
Foreword I
ISO Foreword II
1 Scope
2 References
3 Definitions
4 Sampling principles
5 Apparatus
5.1 Summary
5.2 Tank sampler
5.3 Barrel and can sampler
5.4 Pipeline sampler
5.5 Vessel
5.6 Vessel sealer
5.7 Sample cooler
6 Safety precautions
6.1 Summary
6.2 Equipment
6.3 Sampling point
6.4 Static
7 Operation methods
7.1 Introduction
7.2 Precautions
7.3 Tank sampling
7.4 Package sampling
7.5 Pipeline sampling
8 Sampling methods for crude oil and other uneven petroleum liquids
8.1 Summary
8.2 Sampling method
9 Sample handling
9.1 Summary
9.2 Sample equalization
9.3 Inspection on mixing time
9.4 Sample transfer
