Different thread sealing depends on the geographical region, size of the pressure system, and the environment. For example, In Aisa, such as China, Korea, Japan, etc normally use BSPT; In the U.S, Canada, etc always use NPT, Then the BSP thread is most popular in the UK, Europe, Australia, New Zealand, and South Africa. While one sealing style is not inherently better than another each style has its application.