Abstract
We have succeeded to develop parts of screw joint for API standard FRP pipes which include centrifugal winding (CW) type and filament winding (FW) type. It is a remarkable feature that the developed screw joint parts are pressure-durable and cost-effective, and it can be applicable to almost all FRP pipes. Even if we hit the screw with a hammer, its thread does not be broken different from steel one. Originally it is developed for CW pipes which have breaking inner pressure of almost 100 MPa and working inner pressure of 50 MPa. There are various sealing materials for the screw. Most tight one is to fix by resin, and it will have almost the same durability of the CW pipe as it is. However, it becomes impossible to loosen. If we use urethane, the breaking pressure will be 50MPa, and it is half cured with the fastening torque of 20 kg/m and loosening of 200 kg/m. Other selection will be silicone sealant of 40 MPa and seal tape of 25 Mpa.
