Overview
The high-pressure hydrogenation process is an important means for deep processing of petroleum. It can not only increase the recovery rate of light oil per unit of crude oil, but also can improve the quality of fuel oil, improving the overall benefit of the refinery. The high-pressure hydrogenation device can also provide raw materials with good quality for petrochemical units, which is also an ideal device for oil desulfurization. China has started the construction of high-pressure hydrogenation devices in the 1990s. It is expected that in the next few years, the construction of high-pressure hydrogenation units will still be a hot topic in the petrochemical industry, as the amount of oil refining increases year by year. Various petrochemical enterprises also want to improve their capacity for petroleum refining so as to meet the challenge of joining the WTO.
 
Working conditions
The medium environment of the high-pressure hydrogenation unit has two outstanding features, namely high pressure and hydrogen with hydrogen sulfide operation. High-pressure operation not only refers to high operating pressure which is generally from 14 to 20MPa, but also because its medium is flammable and explosive high-pressure gas that is hydrogen or oil and gas and hydrogen. Gas stores a large amount of pressure energy. Once its storage and transportation equipment including pipelines and valves are damaged, the resulting accident will be catastrophic.
Hydrogen with hydrogen sulfide operation means that the requirements for the materials of storage and transportation equipment are strict. Hydrogen is a medium that can penetrate into metal materials and cause material denaturation or deterioration at room temperature or high temperature. Hydrogen can cause embrittlement and deformation of metal materials at room temperature, and can cause internal and external decarburization of metal materials at high temperatures. The corrosion of hydrogen sulfide to metal materials is also a very tricky problem. Hydrogen can cause stress corrosion cracking of many metal materials at room temperature, and it can cause rapid and uniform corrosion of metal materials at high temperatures. All these characteristics put forward strict requirements for the material, structural design and strength design of the high-pressure hydrogenation valve.
 
Demand situations
The valves in the high-pressure hydrogenation unit have both hydrogen and non-hydrogen conditions, as well as high-pressure and non high-pressure conditions. This article only discusses valves used under high pressure and hydrogen conditions. Although the amount of such valves is small, their prices take up a large proportion. These valves include gate valves, globe valves, check valves, ball valves and plug valves. The pressure rate is ASME CL900 to CL2500; the temperature is from normal temperature to 400℃; the main materials are ASTMA105, A182-F11/F22/F321, A216-WCB, A217-WC6/WC9 and A351-CF8C; the valve diameter is from DN15 to 400mm.

Valve manufacturers in China currently have the ability and conditions to produce high-pressure hydrogenation valves, and they have been successfully applied to hydrofining units with operating pressure from 8 to 10MPa. The design, manufacturing, inspection, testing and quality control for high-pressure hydrogenation valves is done well.