Question: how to test a pvb backflow?
Answer: CLOSE TESTCOCK 2. REMOVE HIGH HOSE FROM TESTCOCK 2. OPEN INLET SHUTOFF VALVE. ATTACH COMPENSATING (BLEED-OFF) TEE TO TESTCOCK 1. ATTACH HIGH HOSE TO BLEED-OFF TEE on TESTCOCK 1. OPEN TESTCOCK 1 SLOWLY. OPEN HIGH BLEED - BLEED AIR FROM GAUGE.