What are the pressure ratings and test duration for 5-inch coupling?

• A. 120 psi max non-locking, 180 psi max locking; tested at 200 psi for 5 minutes
• B. 150 psi max non-locking, 180 psi max locking; tested at 200 psi for 5 minutes
• C. 150 psi max non-locking, 160 psi max locking; tested at 210 psi for 5 minutes
• D. 150 psi max non-locking, 180 psi max locking; tested at 200 psi for 4 minutes

Answer: (B)

The main idea is that pressure ratings for hose couplings depend on whether the coupling is locking or non-locking, and the test uses a higher, short-duration hydrostatic pressure to verify integrity. A locking 5-inch coupling can safely handle more pressure than a non-locking one, so the rated working pressure is higher for locking than for non-locking. For this size, the typical maximum working pressures are 150 psi for non-locking and 180 psi for locking. To prove everything holds up under a stress higher than the working limit, the assembly is hydrostatically tested at 200 psi for 5 minutes. This combination—150 psi non-locking, 180 psi locking, tested at 200 psi for 5 minutes—matches the standard testing practice, ensuring there are no leaks or failures under peak load. The other options either give incorrect pressure limits for locking versus non-locking, or wrong test pressure or duration.