Проблемы разработки методики испытаний неметалли- ческих труб и фитингов и гибких металлических труб на пожаростойкость

Abstract

Advantages of use of nonmetallic pipes as pipeline systems for drencher and sprinkler wet and dry pipe automatic fire extinguishing installations (AUP) are considered. The analysis of advantage of use of nonmetallic pipes and flexible metal pipes in drencher and sprinkler wet and dry AUP is performed. Regulations for design of pipeline networks consisting of these pipes are provided. Distinctions in methods of fire testing of substances, materials and products for flammability, flame distribution, combustibility, fire resistance and fire endurance are shown. The domestic and foreign stands and methods connected with direct pipe testing for fire endurance are considered in detail. It is noted that the bench equipment, test methods and modes stated in domestic and foreign standards and patents for invention do not answer fully assigned purposes. The dependence of change of sprinkler angular attitude on its weight and console length is considered. It is shown that fire endurance as an integral characteristic allows carrying out an engineering choice of specific pipes and fittings for real fire-hazardous objects. There is reasoned the interconnection of test parameters and wet AUP functioning both in operating and standby conditions (wet or dry) with the pipe condition in the course of their operation (with or without water discharge). Nomenclature and the values of the set of parameters characterizing fire endurance are proved. As a set of parameters characterizing fire endurance, there are proposed the test duration before the depressu-rization of the pipe, temperature of tests, hydraulic or pneumatic pressure and water discharge through the pipe carried out automatically in fixed time after the beginning of the test. Test validation of the nature of the orientation angle change of the sprinkler axis (or a spray) must be given depending on its weight, console length and manner of pipe fastening (sliding or rigid). The criterion for the positive assessment of each test is lack of integrity loss of the test pipes and fittings, and also orientation stability of the sprinkler (or spray) in space (within the possible deflection angle). The special design of the test pipe is offered for the orientation check of sprinkler axis concerning the initial position. The stand is developed for the fire endurance definition of nonmetallic pipes (with and without fittings) and the sequence of performing operations is formulated. For control automation of depressurization there were used various technical means responding to pressure drop, to appearance of water streams or smell (at control by a dry pipe).