To solve the problem of oil-vapor coun-terflow and escape in the adjacent gas-phase arms without loading and unloading operation under the condition of gas pressure change and untight sealing of the lower joint of the gas-phase arms for oil and gas recovery under the road loading and unloading operation of oil depots,a solution of installing a clamping piece check valve at the interface of the gas-phase tube is proposed,which can provide a refer-ence for solving the oil-vapor counterflow and es-cape problem in the gas-phase arms under the road loading and unloading operation of oil depots.