| 摘要 |
FIELD: general engineering. ^ SUBSTANCE: invention relates to safety valves and fittings for pipelines and it is designed for cutting off working medium in different pipelines at higher flow rates and low pressures in case of rise of pressure of liquid or gaseous medium in pipelines over tolerable values and in can be used in process lines of thermoelectric plants, nuclear power plants and gas and oil processing enterprises. Proposed safety unit contains housing with inlet and outlet branch pipes and direct-acting safety valve. The latter is arranged in housing and is provided with seat with through hole for engaging with locking member. Locking member is spring-loaded relative to housing and is installed for closing through hole in case of pressure drop of working medium. Locking member is furnished with screen enclosing the seat. Restrictor is arranged on inlet branch pipe. Restrictors of different design versions are provided. According restrictors of different design versions are provided. According to first design version, restrictor is made in form of spring-loaded piston installed on inlet branch pipe for changing area of ring hole between piston and screen when opening and closing the valve. According to second design versions, restrictor is made in form of disk of elastic flexible material for changing are of ring hole between piston and screen when opening and closing the valve. According to third design version, restrictor is made in form of spring-loaded disk of elastic flexible material installed on inlet branch pipe for movement and changing area of ring hole between piston and screen when opening and closing the valve. ^ EFFECT: prevention of influence of working medium forces in outlet channel of safety valve members at final stage of valve closing. ^ 4 cl, 6 dwg |
