Where is test cock number one located on an approved double check valve assembly?

Test cock number one on an approved double check valve assembly is located upstream of shutoff valve number one. This positioning is essential for proper testing and maintenance of the backflow prevention device.

When conducting tests on a double check valve, the location of the test cocks allows technicians to isolate sections of the assembly and measure the pressure across the two check valves effectively. Placing test cock number one upstream means that it is situated on the side that is closest to the source water supply, allowing for an accurate assessment of any potential backflow at the entry point before it encounters shutoff valve number one.

Having this setup ensures that the tests reflect the actual operating conditions that the assembly will experience in the field, which is crucial for evaluating its performance and maintaining water safety standards.