Abstract
Black powder is a common problem in any upstream gas facilities. Black powder causes many problems to the gas treating facility. These problems can be in a form of erosion of gas transportation pipeline, erosion of processing equipment such as gas compressor, impurities in the product and accumulation in flow reduction components and clogging on isolation valves. This all leads to upsetting gas plant operation resulting in numerous cost to restore the plant operation and resolve the problem. One of the critical equipment that encounter black powder problem is isolation valve of safety relief valve. As known, safety relief valves are among the critical equipment in any plant. Safety relief valves are usually installed with an upstream block valve to maintain the operation and facilitate maintenance of the safety relief valve. Therefore, failure of this critical isolation valve will cause difficulties when dismantling the isolation valve as black powder will get accumulated in the cavity area of the valve and damage the seating which will, in turn, prevent full closure of the isolation valve. Realizing this detrimental effect of black powder on isolation valve entails proper selection process of isolation valve type. Nowadays, the industry offers various type of isolation valve. Each type has its own design aspects in terms of the capacity, strength, operator and nature of fluid media. However, the long term reliability comes from experience when valve is put into service. Under black powder operation conditions, passing or leaking after short period of time of operation usually not a good sign of proper valve selection. That is why emphasis have to be given to understand the nature of the processed product and select the right type of isolation valve that will serve for a long time to insure plant safety, reliability and smooth operation. In this paper, a Saudi Aramco gas plant experience will be shared of black powder problem on isolation gate valve of safety relief valve and the remedial action that has been taken to rectify this repeated problem.
