Attributes . Rated pressure for connected Brass Unvalved Coupler and Brass Plug: 300 PSI (20 bar) Maximum Working and 10,000 PSI (700 bar) Burst; Rated pressure for connected Brass Unvalved Coupler and Steel Plug: 500 PSI (35 bar) Maximum Working and 10,700 PSI (750 bar) Burst . Names