300 series RUST shut-off valves

RUST shut-off valves of 300 series are designed to shut off the flow of working medium with a certain tightness.
Structurally, the valve consists of a shut-off unit, body, cover and parts of the stem gland seal.
Working medium for valves are liquid and gaseous products: water (drinking, technical, sea), steam, oil, oil products, natural gas, oxygen, acids, alkalis, chemically active, explosion and fire hazardous media, including those containing hydrogen sulphide, liquid hydrocarbons, ethylene glycol, turbine oils, carbon dioxide, methanol (CH3OH), oxygen, water and mechanical impurities.
Service life before writing-off is 40 years, service life before writing-off for DN 10 to 200 - 4000 cycles, for DN over 200 - 2000 cycles. Guaranteed service life of valves is 24 months from the date of commissioning, but not more than 36 months from the date of shipment from the manufacturer.
The valves are hermetically sealed in relation to the environment; if the rules for operation and maintenance are observed, they are not so...