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In the literature data, much less attention is paid to the study of the stress-strain state of pipelines and metal structures of site facilities than to similar objects of the linear part of main pipelines. This article analyzes the capabilities, advantages and disadvantages of existing approaches to the experimental determination of the parameters of the stress-strain state of technological pipelines and other metal structures used at oil pumping stations and tank farms. For these products, characteristic sizes range fr om several tens of centimeters to several meters. This is a significant difference fr om the linear part, wh ere the characteristic length starts from ten meters (the length of one pipe section).The possibilities of application of tensometry, optical, magnetic and ultrasonic methods are considered. Examples of attempts to practical implementation of these methods at site facilities are given, and problems that hinder the implementation of these methods in the practice of diagnosing objects during operation are noted. Among these problems, the main ones include the following. As a rule, there is no information about the initial state of the metal structure before operation and the history of their loading during operation, the chemical composition and methods of manufacturing controlled metal structures vary widely, the results of measuring and calculating the parameters of the stress-strain state depend on the chemical composition and method of manufacturing metal structures, there are no generally accepted established requirements for samples for standardization of mechanical stresses in a metal. The article states that it is advisable to measure the parameters of the stress-strain state of metal structures using a set of complementary methods. It is also advisable to supplement these measurements with calculation methods for determining stresses. It is noted that currently there are no methods that fully meet the requirements for measuring the parameters of the stress-strain state of metal structures as part of the site facilities of trunk pipelines. Promising methods for determining the stress-strain state are noted. References 1. Makhutov N.A., Prochnost' i bezopasnost': fundamental'nye i prikladnye issledovaniya (Strength and safety: fundamental and applied research), Novosibirsk: Nauka Publ., 2008, 528 p. 2. Lisin Yu.V., Ermish S.V., Makhutov N.A. et al., Impact of stress-strain state of the pipeline on the lim it state of the pipeline (In Russ.), Nauka i tehnologiya truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2017, V. 7, no. 4, pp. 12–16. 3. 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