PURPOSE: To contrive to reduce a cost of manufacture while contriving to decrease a number of part items, by constituting a press contact connecting mechanism of pins protrusively provided in the periphery of each pipe and of a tension spring extended between the opposed pins of each pipe.

CONSTITUTION: A spherical joint is provided with a seal part 32A and a press contact connecting mechanism 30A. As the press contact connecting mechanism 30A of building the seal part 32A with prescribed set force, the mechanism 30A comprises pins 40 protrusively provided in the periphery of each pipe 6, 7 and a tension spring 50 extended between the opposed pins 40. The pin 40 is formed in both ends of a single curved bar member 44. The curved bar member 44, by fitting a semicircular curved part 44a provided in the intermediate part welded, is integrally formed with the pipes 6, 7. By only engaging a hook 52 in both ends of the tension spring 50 with the opposed pin 40, while introducing a prescribed set pressure into the seal part 32A, the pipes 6, 7 can be connected. In this way, assembly work can be easily performed, to attain reducing a cost of manufacture.